All Wheel Drive Auto: Independent Seattle Subaru Service


Seattle Area Subaru Burnt Exhaust Valve

A fairly common repair we have had to make to the 2004 and up Turbo charged 2.5l is a valve job as a result of one or more burnt valves, but what is a burnt valve and more importantly how can I avoid it?

Subaru Exhaust Valve Issue in Seattle
Subaru Exhaust Valve Issue in Seattle
Subaru Exhaust Valve
Subaru Exhaust Valve Problem
Subaru Burnt Exhaust Valve
Seattle Subaru Burnt Exhaust Valve

Typically what causes a valve to become burnt, worn or cracked is excessive heat either do to lack of lubrication or excessive combustion chamber temperature as a result of the  incorrect  fuel mixture.  A weak fuel injector is typically the culprit on an DOHC Turbo charged models from 2004 to 2008.  This usually starts out as some rough running when cold and finally setting a check engine light with a cylinder misfire code.  If the weak fuel injector is not caught it can slowly overtime allow the combustion chamber temperatures to become higher than designed ultimately damaging a valve.  There are of course other reasons this can happen such as tolerances that are not within specs, or a driver that constantly pushes the oil change intervals a little to far.    Its also possible that the valve it self is defective we have seen that as well.  What we have noticed is that based on the misfire data observed form these engines when cold there can be some minor signs of trouble long before the check engine light is ever illuminated, we whenever possible for our local Subaru customers in the Greater Seattle area will connect the Subaru Select monitor to the Turbo models and try to look at some data from history if we don’t get an opportunity to have the vehicle cold.

If you own one of these vehicles and if you start to notice a vibration from the engine when cold at idle I would encourage you to have the misfire data monitored especially if you have a vehicle that is still under Subaru’s 5 year 60,000 mile power train warranty as making the attempt to complain about it ahead of the warranty expiring may extend the warranty for you a bit .  We typically suggest a fuel injection service starting at the 60k interval as maintenance and I can tell you we that when we have observed a weak injector there really hasn’t been to much we have been able to do short of replacing the fuel injector it self.

I wan to stress that its after we have seen the same type of issue multiple times and think we have a theory on whats happening and can provide  some information that should help Subaru Owners avoid an expensive repair that I will finally post the article. If its a one time thing there is almost never going to be a post about it, but after 6 or 7 repairs a theme is starting and I believe it time to get some information out to our readers.

Thanks for reading



57 Responses

  1. I recently had a rough idle and stalling on a 2013 Subaru STI on cold starts. If I would allow the engine to warm up where the idle came down to around 1000 rpm it would drive perfect. It would not even throw misfire codes or counts on my Cobb AP. Shortly after this started occurring for a few months I spun a rod bearing just driving down the road at 40MPH, not pushing the car at all. Car has 88,000 miles. When the engine was pulled the valve clearances were out of spec. I took the heads to a reputable shop and had them restored. 3 exhaust valves were bad, and 1 guide had pushed down somewhat out of the head, so they replaced the valves and 2 guides. My car is modified. It has ID1050x injectors and a 6 micron fuel filter. Cobb fuel lines and rails etc. The car is a daily with a ton of highway miles. I always changed the oil at 3K or less, and changed the fuel filter regularly. The car was tuned by Calvin a tuner at Cobb tuning in TX. The AFR ratios always looked good within +/- 5 %. Any ideas what could cause the valves to wear like this? I do know Subaru quit putting sodium filled exhaust valves in the 2008+ sti Just thought I would get your opinion. I have had this happen before on a 2005 Outback XT at 165K so on this 2013 STI I installed the 6 micron fuel filter after reading your article to keep the injectors clean.

    1. Hey Greg,

      Combustion Temperature, Oil Temperature and Cooling system Temperature all play a part in how long valves seem to last. Lean conditions will affect Combustion temps as will the quality of the Fuel, quality of the oil will affect oil temps and the overall health of the cooling system and the Engine at large will affect the cooling system temps. Generally speaking we typically see years of low grade fuel, restricted injectors, and carbon deposits creating hot spots be the main culprits.

      Have you post repairs, done any looking around with a Infrared thermometer to see how balanced the temps are between cylinders?


  2. 2005 outback 2.5xt. I took off the oil filler cap and felt air. Not massive amounts but air flow nontheless. Third cylinder code. Is that the piston still?

  3. Justin,
    Thanks for your prompt response. The motor is at 195,000 so… As for the head bolts OE for sure, I am not set up to check for stretch and will make sure to go through the proper FSM sequence for tightening the new bolts. The cobb would be used to monitor and do an etune. I am assuming the number 4 piston is the most convenient to remove? Or is it the one that sees the most wear due to location and oiling? Last question, whats your thoughts or advice on flywheel resurfacing, is a blanchard grinder or specific RA something I should be asking about? Anyhow thanks again for all you do. Keep up the good work.

    1. An omni non directional finish is important for the Flywheel resurface.

      #4 piston is the common one to end up with a cracked piston in the Piston ring area.

  4. Justin,
    Thanks for takin the time to give good fact based advice. I have a 04 xt forester that burned a valve on the number 2 cylinder. I diagnosed it myself with 70%leakdown from that cylinder. All other cylinder had acceptable leak down and @120psi compression at 3300 ft. I removed the motor and sent my heads to a reputable subaru machine shop, he mentioned I probably had a lean condition that cause that exhaust valve to burn and the rest of the valve train to be beat up. My questions for you are: should I go with a new short block at this point, considering the original blocks Milage? The cylinders do have a few “scratches” that I can’t get a fingernail in. The turbo is tired and has shaft play, so I am thinking about replacing. At this point I have my mind set on the following and would appreciate your advice.
    New shortblock, new or slightly used turbo, new oil cooler& oil pump, water pump, timing kit, clutch and new hoses all around.
    Can or should I reuse my cylinder head bolts? Also i sent the injectors out for cleaning and rebuild and will do a balance test on them. Would a cobb ap allow me to keep my eye on the short and long term fuel trims and or o2 sensors to look for a lean condition in the future? is a wide band 02 another safety measure? Thanks for your insight.

    1. Hey Sean,

      I think you left out the mileage? I always have to worry about the piston ringlands on the Turbo 2.5l, so if you are okay with spending the money on a short block and taking care of the Turbo I would say go for it if its over or around 100k. If you want you could remove the cylinder # 4 piston and inspect it. I would not use an aftermarket front air fuel sensor, I like the Cobb Access port idea, but only if you will also utilize the re flash for more power aspects, if not and you want to stay stock there are other options for monitoring.

      If you can’t check a head bolt for stretch than yes replace them, I must stress nothing aftermarket unless you are going to Stud it, which is not needed unless you are doing a build, rather than a stock engine replacement.

      Hope that helps


  5. Justin,
    Thanks for this article, I appreciate you sharing your perspective. Can you offer me some advice on my predicament?

    My 2006 Forester 2.5xt has 96k and has been well kept with frequent oil changes and a major service at 60k. Last week I took it in to the dealer to investigate a CEL and blinking Cruise Control light. The dealer diagnosed the car with burnt up valve(s) and a failed cat. converter.

    The quote from the dealer is $6,750 to repair. I love the car but the cost of the repair is huge

    Details from the diagnostic report are as follow:

    -Misfires on 3 cylinders: P0304,P0302,P0301
    -Spark Plugs and Coils OK
    -Recommend check valve clearances
    -Code P0420, needs new cat. converter
    -P2440, air injection valve seized, recommend replace both

    -Does this quote pass your “sniff” test?
    -If I were to pay this type of money, how can I be confident that this issue won’t arise again?

    Any input helps, thanks.

    1. Hi Jeff,

      That’s a lot to swallow all at once indeed. Had the CEL been on for a while? Id be inclined to address the Misfire code and Secondary Air injection via a valve job and than air injection valves and or pump as needed and drive it a bit and see if it actually needs a converter, s it can not be tested with a misfire and most likely was not tested only an assumption made.

      The price is hard to disqualify or qualify as okay as I don’t know the market where you reside.

      The bigger issue is I don’t know what they have done to determine why it needs a valve job, its quite possible it does, but I like to see notes like “called customer and got authorization to remove valve covers and check valve clearance, found cylinder # 4 to be out of spec, found cylinder # 2 to be slightly out of specs” etc.

      Whenever I don’t see that type of fact based diagnoses, I don’t know what testing was done, but that’s the right way to serve your customer suggest repairs based on facts. We have had cars here that a Dealer said needed an engine when it was just a Turbo, or needed a valve job when it was actually a corroded # 4 coil connector (which is Quite common).

      “-Misfires on 3 cylinders: P0304,P0302,P0301
      -Spark Plugs and Coils OK
      -Recommend check valve clearances
      -Code P0420, needs new cat. converter
      -P2440, air injection valve seized, recommend replace both”

      This above indicates a pencil whipped diagnoses with no real statements of fact or proof of failure.


      1. Justin,

        Thanks for the insight, it really helps my overall understanding. I have an update after receiving a second opinion on the car from an independent shop.

        There diagnostic process was as such:

        1. Cleared the error codes

        2. Test drove the vehicle and observed that only the seized air valve code (P2440) came back. They also observed that the car was running very smoothly and did not show symptoms of gross ignition misfiring. They said that the code indicated an “open” failure but somehow they concluded that the valve was actually in the “closed” position.

        3. They measured temperature at the Cat. inlet and outlet to be 160deg and 220deg, which implied overall function, although some “rattling” sound could be heard somewhere in the exhaust system in that area.

        Their conclusions:

        1. The air valve failure could very well be the cause of the cat error code and the misfiring codes. The misfire reports indicate a very intermittent miss that is not reflective of a “burnt up valve”
        2. Recommended that I pay for them to remove the Cat to assess inner honeycomb for damage.

        3. Overall quote for the valve and cat. investigation is $1100.

        Even if they are wrong on some of these points, I at least feel that they provided a deeper investigation than the dealer.

        What do you think about these hypotheses?



        1. I think they have spent more quality time with your car, however the removal of the cat thing is a little off.

          It would be better if they had looked to see if the Convertor was reaching light of by graphing data from the rear 02 sensor. Other than that I think the plan sounds more reasonable than where you were before.


  6. Thanks for the post. I wish I read this when our 2005 Legacy turbo wagon started running a tad rough cold a few months back without a CEL.

    So far a compression test had air blow out the exhaust the engine is coming out Monday.

    So I should have the injector’s tested to find out what led to this?

  7. Justin,

    I must say this is some of the most informative and relevant information I have seen on this subject. I have a 2006 Subaru WRX that was recently diagnosed with a burnt valve on cylinder number 2. The car has about 185,000 miles on it and I have loved driving and owning the car; up until this point I have really had no issues with the car, except one that has been not a show stopper and I am not sure if it is related to the burnt valve.

    At about 60,000-90,000 miles the car started doing an occasional sort of sputter. It would typically occur when driving on the freeway at little over 3,000 rpm in 4th or 5th gear. THe car would usually start feeling like it was loosing power and getting it back and jerking pretty good. By shifting down and moving the rpm up the problem would typically be resolved. The issue was random enough that about half the time I’d take it for a service to have someone give me an opinion on it it would disappear. It was speculatively “diagnosed” as being an issue with my catalytic converter being plugged and causing issues with the turbo waste gate, or early signs of issues with the valves. At about 130,000 miles I had a cylinder 4 misfire code come up and a local shop simply tightened the coil packs (as one of them was loose) and the issue went away. While talking with a local shop and the dealership they were speculating at the time that the valves were likely the culprit. In fact, in my opinion they confirmed the fact that that vintage model WRX was seeing valve issues and they seemed to attribute it to not doing a valve adjustment at 60,000 or 90,000 miles. Seemed strange to me that Subaru would not have that as a required maintenance if it could make the engine fail; further more it would seem that it would be in their best interest to make a small valve adjustment to perhaps prevent burning valves prior to the warranty expiring.

    My real question is I am trying to assess if a 2006 Subaru WRX with 185,000 miles is worth trying to save. Through out the life of the car I have maintained it pretty religiously per the OEM recommendations, used almost 100% synthetic oil (the original dealership I was servicing the car at did not recommend using synthetic). My options right now are doing a valve job (“the top of the engine” – cheapest option), rebuilding the engine completely (most expensive option), and doing a valve job and refurbishing “the bottom” of the engine (bearings, rings, seals, etc… as somewhere in the middle). I am also a little concerned about the turbo (still the original) and I guess I am trying to get a feel for a) how reliable the part of the engine that is not currently damaged (in theory) is and b) the reliability of the rest of the car (transmission, electrical, etc….). I’d hate to go in there and spend near or more than the car is worth only to have another major issue pop up in the near future…. I understand you guys are not fortune tellers and and I am not looking for any kind of answer on wether I will have something else fail, but more on your experience on the longevity of the car as a whole.



    1. Hello Frederick,

      The vales not being adjusted could have contributed but most likely not, we work on plenty of Subaru’s with 300k and counting with the same valve train configuration (pucks) and the valves just are not out of adjustment much.

      “I’d hate to go in there and spend near or more than the car is worth”

      Now I am not picking on you but this is very the statement that continues to confound me from many who post here.

      If the car suits your needs, you like it and you can find someone to fix it, what does the value of the car matter? The only time blue book matters is when you go to sell it, and unless you are in the business of flipping cars what it cost to fix Vs what its worth to sell have no bearing. Its a tool, if you break an Ax handle you can go buy a brand new ax or instead a handle for half the cost, while its true the new ax is worth more at a garage sale then the old one it took more money spent to get there.

      Think about whats less 40k on a new WRX or $6000.00 spent on one you already own. Plan on a clutch, and maybe a coupe of wheel bearings in the future other than that I would replace the turbo as maintenance if you replace the engine and maybe the clutch at the same time as well.

      The 2006 WRX on the whole is a good car, but its also a Turbo charged performance vehicle and performance and longevity do not go hand and hand regardless of any sales hype.

      I would encourage you to fix it, what I always say is if you don’t someone else will and most likely will love the car.

      Now if you want a new car, go buy one I get it, but do it because your in a good place to do so, because you know what, you could fix this Suby but nah its time for a new owner and you really have liked the BRZ or 2013 WRX Limited for a while and here’s the excuse.


      1. Justin,

        Thank you for your response. The WRX is a car I have enjoyed tremendously and in my opinion really matches the description of the “tool” I need in a car: versatile, AWD, safe, and has many of the added bells and whistles I like: power, style, etc…

        I could not agree with you more on many of the points you made, however when people think of buying a new car and giving advice on the subject I think they often think of the cost of the down payment and the monthly cost and not the whole cost of the car.

        I have spoken to a couple of shops in the area and the basic recommendation from one was that a valve job on a WRX with 185K miles on it just did not make sense and that for the cost of rebuilding the engine I’d be better off rebuilding the whole engine. I think if that were the bottom line, I’d be ok with that, however my concern is that it is going to end up being the engine, plus the turbo, and who knows what else comes up once they get in there. On top of that I was told that their “boiler plate” provided no warranty on the new rebuilt engine, but as long as I was reasonable and did not do any thing stupid that they would take care of any issues (sort of a “verbal agreement”). Another shop that a friend works at said that the “bottom” of the WRX engine is pretty much super solid and other than new bearings, seals, rings, and some possible touch up and inspection of the cylinders that I should be fine with doing the valve job and “touching up the bottom of the engine”. They said this would basically be an engine with 0 miles on it. However, once again, no warranty on the engine, but that “they would take care of me if something happened”… Is it typical for shops to not provide a warranty on big jobs like this?

        The clutch was done at ~120K miles. If I were to do the valve job or any of the rebuild options I’d likely do the timing belt (and all the associated components). I am planning that if the engine work is done, it is likely about time to do the turbo as well. Other than the OEM part for the turbo is there any other options on fixing and replacing the turbo that make sense? Rebuilds? After market? Or am I best off just using the OEM part?



        1. Hello Frederick,

          Nothing but an OE Turbo in my opinion.

          “boiler plate” provided no warranty on the new rebuilt engine”?

          You should let someone who will offer a warranty do this.

          If it was here there would be a 15 month 15k warranty, that is a little better than Dealer standard which is 1 year 12k. Accept nothing less.


  8. Hey!! I am working on 2006 outback. Cylinder 4 misfire . Tryed everything allready( coil pack, oem plug, injector, BG cleaner) still misfiring . Did compression check-140psi. Can it still be burnt valve? Thanx

    1. Hello Max,

      You can check valve clearance and see if one or more exhaust valves are tight. Also the wires to any of the 4 coils can corrode but we see it a lot on # 4. Have you measured voltage and reference at the coil as well as wave form of the ignition pattern or are we just replacing parts?


  9. I too am getting a misfire on cylinder 4 CEL. I have replaced the ignition coil and plugs and the same code has returned. Earlier you mentioned checking for an unstable vacuum reading. What would that look like? I have connected in a gauge with a tee at the MAP sensor. My reading wiggles fast between about 19-20 in HG. Is that behavior potentially indicative of a burnt valve?


    1. Hello Mike,

      Unstable would be just that, bouncing all over the place and more than 2 inches of mercury. Your readings do not rule out a tight valve but may rule out a burnt valve.

      Fuel injector, or wiring to either the coil or injector is also another possibility.


  10. I purchased an ’06 Outback XT with just under 80,000 miles back in November 2012 from a Subaru dealer. It now has 82,000 miles. As I write this, I am stuck 4 hours away from home on a vacation that has turned into a nightmare.

    On Monday this week I had to have my car towed the last 1/2 of the way to the dealer that is local to me because the engine was idling extremely roughly and the engine check light was on. Tuesday morning they did a compression test which showed 100 psi in cylinders 1, 3 and 4, but 30psi in #2. They did not perform a leak-down, which I thought odd. They said to diagnose further, they’d need to remove engine & heads, which I authorized.

    Today (Wed), they tell me one of the exhaust valves is burned and there is oil in the cylinder. They are quoting $2800 for complete valve job (including new valves, guides and machined heads) and new rings. I am completely stuck here 4 hours from home. After reading this thread, I suggested that they also perform a flow test on the injectors while apart. They said that they didn’t plan to do this, and didn’t want to do a bunch of extra work that would cost me a lot more money. In any case, it probably can’t be completed in time for me to return to work, meaning another round trip back here next week to pick up the vehicle. I don’t have another car and no one to come & get me, so I’d need to rent.

    I’m a pretty knowledgeable about cars but this is my first Subaru and right away I’m stuck with this situation.

    The work needs to be done ASAP so that I can get back home. I will be calling them tomorrow (Thursday 2/14) to authorize the work but I want to do what’s right.

    Complete T-belt service?
    Flow test the injectors?
    Turbo shaft inspection for sure.
    New union screw for sure, but what about the two related to the ACVS – replace those also??
    Anything else while the engine is out – seals or something?

    Thanks for any info you can get to me before they get too far into this procedure.

    1. I am sorry but I am way to far behind to be of much help by your deadline.

      Timing belt, union screws while it is apart. You can heave the injectors tested, cleaned etc when you are back home, a weak spray over time can cause the issue, but its not the only reason a valve can fail, its just one of many.


      1. Thanks Justin. I’m back home with a rental car now.

        I am going to have the t-belt & related components replaced, and I found out that the union screws were already on their to-do list while engine is apart. I did have them inspect the turbo and they found the seal is bad, so we’re looking at replacing that also.

        They also found a broken ring land on the #2 piston. Could this be related issue to the burned valve?

        Would sticking to using only Chevron gas with it’s Techron help keep the injectors healthier?

          1. I found this and am searching for help….I posted this on the lgt forums but would love your take on the issue, Justin.

            Looking for some advice/opinions on this issue…

            Quick background: I own an 08 legacy gt with approx. 36000 miles. Purchased the gold plus extended warranty. Warranty is good until July 2014.

            Roughly 6 months ago my check engine light came on while I was at a red light, took it to the dealer I bought it from right away. The CE light was as a result of all 4 cylinders misfiring. They reset the car and sent me on my way. They said something along the lines of “give us a call if the light comes on again”. A few weeks go by and bang the light comes on again. Immediately call dealer who told me it would be a 5 day wait before I could setup and appointment. I told them to get lost seeing as they told me to seek them out if I had any issues…

            Onto new dealer. Took the car in and they had the car for 7 days total. Same problem this time…misfiring in all 4 cylinders. They tell me that the problem is the oil control valve(s) and replace both of them. This repair was covered under warranty. I picked up the car, drove off and was happy to have it fixed…or not.

            A couple days ago the CE light came on again. Dropped car off this morning. Guess what? All 4 cylinders are misfiring still. Service guy tells me that I need my valves adjusted and it costs $2500!!! I am flabbergasted on the phone. My warranty doesn’t cover something related to my engine not operating properly? I told them not to touch the thing and that I would be down in the morning.

            My question is what should I do now? I feel this should be a warranty repair. They supposedly “fixed” it 2 months ago. I have been driving around like this for months potentially damaging my engine? No? How do I know that this will even my fix the problem?

            Appreciate your thoughts…thanks.

          2. Only way to tell if the valves need adjusting is to remove the valve covers and check clearance.

            In order to adjust the valves properly it is necessary to remove the cams, but I doubt its just an adjustment.

            By the way you have a 5 year 60k power train warranty that will not cover the valve adjustment but will cover burnt valves.

            Because you and I both have a bad feeling a call to SOA is needed, as well as you requesting to see that the valves are just out of adjustment and not beginning to burn.

            After all of that Im still not sure the diagnoses is correct and I actually suspect something else entirely.


  11. I own a 2005 2.5i Outback with almost 160k. I just had some major work done on my car including head gasket repair along with water pump timing belt, along with a ton of other components that come a long with that.

    The car is running great, however it sounds like our 79 Mercedes diesel. I was told that it was the valve adjustment that is making it sound so loud. He said that he set valves at the factory recommendations.

    I am obviously concerned that the car is going to be damaged and am wondering what the valves should be set at in my car. He is a local shop and has made these adjustments by hand, not sure if they are done in a different way at the dealer.

    Should I go back and have them adjust them again? I don’t want a burnt valve from tightening them too much but I KNOW that my car has NEVER been this loud.

    Please help. Should I take it to the dealer of back to the local mechanic to have him make additional adjustments?

    What should the valves be set at???

    1. Hi Erin,

      If the valve lash is higher or larger than specs than yes there will be increased valve train noise but having said that I don’t know if that’s the noise you have. The shop that did the HG needs to handle it for you under warranty and yes its troubling that they have had one go and not corrected it. The adjustment is done by hand and the specs are Intake @ .008 and Exhaust @ .010 but I am not sure how that’s going to hep you unless you are doing it your self?


  12. Justin,

    Thank you for all the info regarding this issue. I just found your site. I have a 2006 Outback XT with 66k miles on the clock. I have been the only driver (casual driver), the car has been meticulously cared for and has only seen premium gas. About 2 months back, the car started to run a bit rough at low idle and CEL came on shortly thereafter with a cyl#2 misfire code.

    Compression and leakdown tests pointed to valves. I took the car in for repairs and the machine shop said the exhaust valave were beat! He thought it was due to excessive temps (burnt valves). One valve was the problem child but all the vavles were in need of TLC. They have all been remachined.

    The car will be repaired but I am trying to identify the root cause of the problem. I thought I would start with the following:

    – Clean MAF
    – Clean injectors
    – Check air intake system for leaks
    – Check fuel pump

    Anything else you recommend I check out or replace. The car has never had an issue unitl now.

    Thanks in advance!

  13. Thanks Justin, really appreciate the advice and the speedy reply! The Subaru dealer is only sending out the head with the problem – the sales manager said his tech checked out the other head and it is “fine”. Is it possible the dealer tech could check the valve seats? The sales rep seems to like to dance around my specific questions via email, he won’t confirm that the tensioner and idlers are being replaced on the timing belt even though I’ve asked about that twice. I also think they have only done a compression test and not a leakdown test on the cylinders. They have checked the turbo shaft and the sales guy says he will have his tech look into the union bolt screen and acvs bolt screens.
    The sales guy just keeps saying “I assure you the car will be 100% solid”. Hmmm, I’m looking for a local Subaru specialist to do the pre-purchase inspection when they have the car ready. Seems like a must in this case. Thanks again!

    – Tom

  14. Hi Justin, thsnks for the informative article, great information. I’ve got a deposit down on a 2004 Forester XT 5MT with 80k miles on it. I’ve been looking for one of these for a while for a ski car as it seems like a great blend of practicality and sportiness. I’ve missed a couple of these as they seem to sell really fast and are very rare here in NY. I spotted this one on the dealer’s web site before they had it ready to roll, put the deposit in because I couldn’t go look at it right away and then got a call that they had found a bad valve when going over the car. The valve is being repaired and timing belt is being replaced while they have the motor apart. They assure me that the car will be 100% solid for me…what questions should I be asking? Should I run from this one? It sounds like the fuel injectors should have a balance test and perhaps leakdown test on all cyls done by an independent mechanic before purchase. What would you suggest? Thanks in advance!!

    1. Hi Tom,

      Yes to the PrePurchase inspection! I would inquire if both heads will be sent out to a machinist for a complete valve job, rather than just the one cylinder addressed. If another valve was starting to fail, it would be apparent only after removing the valve and looking at the wear pattern of the valve face and the valve seat in the cylinder head.

      I actually think you may be getting a great deal if this is done correctly as it really should be solid for some time to come.

      Fuel injection cleaning, yes.

      Complete Timing belt service, Tensioner, Idlers etc

      Rest of the fluids serviced, turbo shaft inspection and new union screw.

      There is a updated Air bag connector for under the front seats, make sure its been done as well.

      Hope it all works out


  15. Thank you for the article. My 05 LGT goes in monday to my local dealer for a diagnostics. P0302 for the past 2 months.

    Bought the car last year with 117,000 miles, just turned 129,000 today. I’ve been chasing this misfire, swapped coil packs, new injector, new spark plugs to no avail, clear code each time and each time #2 CEL. Checked timing this past weekend when I did the timing belt/water pump, all have checked out. Yet CEL still there, and it has begun to occasionally blink when stopped.

    I fear I am already too far gone, and that they will find the burnt valves. As I TRY to do all my own work, what kind of cost would I be looking at to redo the valve train, and should I do both sides even though it’s #2? The tapping when it’s cold, or pulled into neutral, is not making me feel too good either. My biggest concern is this is my daily driver and I would be borrowing against my 401K to pay for it. I love my LGT and have done what I can for it, but I feel like I’m gonna lose this battle.

    Sorry, I don’t mean to make this uncomfortable, but I’m just trying to cover all the bases here. Thanks in advance.


    1. Sorry to hear about the finical difficulty, I would plan on a “both sides” or complete valve job. You don’t want to go through all of this only to have to do it all over again if a valve on the other side has an issue next year, its really better to let a good machinist have a look at all of the valves and seats.


  16. My 2005 legacy gt has an engine with a burnt valve in #2. It happened out of nowhere. I switched the car from gas to e85 ethanol blend over two years ago and have had nothing but the smoothest running engine possible. I gained a little bit of HP and torque with the ethanol, and never really cut it loose unless I had to on the freeway to pass or merge. The fuel injectors were replaced for the ethanol switch, so I have a very hard time believing that the valve went bad because of the fuel injector. This sounds like a far more common problem due to poor design/engineering of the heads by Fuji Heavy Industry. I have read about numerous ej255 motors having burnt valves with low millage; my own car only had 90k miles on.

    I now have a worthless car that I love dearly. I really don’t want to sell it to some chump who will slap the cheapest fix in there and flip it for a profit. I have decided to rebuild it, and with the right parts from the right people. I refuse to throw any OEM stuff in there because it would be a waste of money if I have to do it all over again, as some people have done before. Instead, I am opting for the Cosworth crate long block with a 9.2:1 compression for the e85 fuel. If I am going to spend thousands of dollars on a new motor, it might as well be the best of the best. There are few engine builders more respected and sought after than cosworth, and I will consider it a privilege to have one of their blueprinted and balanced high performance motors in my humble little Subaru Legacy gt.

    1. Tom,

      Because its a different valve each time I hear about this or see it locally, meaning its not always # 2, # 3 etc, and all the valves are the same and are the same valves used in other engines its hard to pinpoint the design you would change. I really want you to have the injectors flow tested while its apart we have seen 4 brand new injectors flow at different rates. Cosworth is great for tens of thousands of dollars, great performance but understand it may not be a 100,000 mile engine.

      Another cause of this is heat from lack of proper lubrication.

      Hope that helps and bets of luck.


  17. I purchased a 2007 OB XT new in 2007. At 58,000 miles had a #2 misfire code and under warranty all EX valves were replaced. Dealer said be thankfull the car was still under warranty with no reason for the cause. 40,000 miles later it happened again now the cost is mine,$3500.00. SOA said they will help with $1250.00. Dealer said the cause was probably due to cheap fuel. Every drop of fuel that has been pumped into the tank has been Cheveron premium, not once has there been cheap fuel in the car. The purpose of this post is to thank you for letting Subaru owners know the probable cause of the burnt EX valves. I suspected it was a fuel delivery issue but the dealer would not hear of it. Just got the car back and will take it somewhere else and have a fuel injector service accomplished, but first need to have the large oil leak and a strange whinning noise fixed that was induced from the engine removal and reinstall. Thanks again Justin, Mark.

  18. Hi,

    I have a 2005 OB XT and have the cylinder 4 misfire code causing the check engine light intermittently. It’s been happening for the past year or so. It will come on and then after a few weeks will turn off, then back on, then off for a couple months. I did go for quite a few months without it coming on over the summer but then it reappeared at the end of september/beginning of october again. The car runs great and has power. The check engine light always comes on while I’m idling or slowing to an idle. It never comes on when I’m accelerating/cruising. My past 3 tanks of gas I have added injector cleaner and octane booster to my super gas hoping theres some minor clogs that can be cleaned out.

    While the car was still under warranty a couple years ago I brought it in because it has a rough idle alot of the time. The tech dismissed it and said these cars tend to have a rough idle and that it was normal. Do you think I most likely already have a burnt valve? How would you treat the situation? Think I have any recourse with SOA since I did bring it in for the rough idle?


    1. The best way to diagnose it as a possible burnt valve is to do a valve clearance check, typically the valve collapses into the seat a bit pushing the valve stem closer to the Cam follower or Puck. Until that step happens you just wont know.

      As far As Subaru Goes.

      If you had brought it in many times for a rough idle, than yes SOA may need or better yet be willing to help.

      But if it was a one time thing than no, unless somewhere on the invoice it stated they were unable to locate cause of a cylinder # 4 misfire. And I also am not sire the 2 are related? The Turbo cars are a bit rough in the Am, but a misfire is a different thing all together.

      Sorry I dont have better news.


  19. Justin,

    Similar to Kim’s issue, my wife has a 2003 Baja. She loved it from day one and has been faithful with the local dealer. Only minor stuff and I admit she has 147K on it, all highway. While following me up a hill, the car check engin came on and threw the #2 misfire code. Needeless to say the stahl cuased a minor off the road incident since power steering pump dropped out and she was unprepared. Religous oil changes and no reports from the dealer. Report they gave me was #2 exhaust valve was cooked. Compression test in fron t of me, decayed fast. Price is high $2800 but that includes both head gaskets. Again, no vibration symptoms, nothing. I got my monies worth and then some, 147K hardly no issues, but if I repair it, what are the odds I will be in there again in 10K. My thought is push for all valves to be checked since the heads will be off or trade the car in. Thoughts? BTW – love the site, more than informative, Wish I was on the west coast.

    1. Chris,

      As long as the repair is done correctly it will last much longer than 10k. I would be embarrassed if our Customers only obtained that type of longevity or lack there of after we had repaired their car. I would have whoever does the repairs look at the Valve guides on the 2003 SOHC for signs of dropping.


  20. Hi,

    I recently had a burnt exhaust valve on the no. 4 cylinder. The dealership did the valve job and it seems fine after about 2,000 miles. My concern is they never were able to give me any explanation of what caused the problem to begin with. They simply said something along the lines of “it happens” After coming here it seems like I could have an issue with injectors that could result in a repeated burnt valve. Is this something I should look into right away or could it wait until my next service.

    1. Hi Andrew,

      Yes they fix whats broken and give no thought to why in many cases.

      It would be good preventive maintenance to have a fuel injection service performed, and inquire to if the Dealer logged any cold morning misfire data on all other cylinders.

      Hope that helps


  21. I purchased my 2005 Baja in June of 2004 and I have loved it, treated it right and had it serviced at Subaru of Richmond religiously ever since.
    On Friday evening I was told my Baja would cost btwn $4300 -$4700 to repair and take 2 weeks or more due to burnt valves…….I am shock.
    This because of a symptom in my Baja that I started trying to research over a year and a half ago
    In August 2010 on a routine service visit I complained of a jerking feeling while driving – they found no codes & unable to duplicate it, released it back to me.
    June of 2011 during another routine maintenance I had them research an erratic idle – they found no codes.
    November 11th of 2011 asked service to research the “Check Engine” light – my receipt shows they found a misfire on Cylinder 4, could not duplicate and cleared.
    November 18th of 2011 – I RETURNED TO SERVICE to again research the “Check Engine” light – my receipt shows they found a misfire on Cylinder 1 & “cleared at no charge to customer”
    Now on February 17th I was informed that they must replace the valves on Cylinder #4 and I am unable to drive the car or I may cause another $1000 dollars damage to the Catalytic Converter.
    I just cannot believe this has happened to me with a Subaru – I know this is not supposed to happen.

    1. Hello Kim,

      Based on the age of the vehicle when you reported the first instance of cylinder misfires it was out of warranty the at the first instance. Its hard for me from here to tell you if a fuel injection service would have helped you avoid this issue back in 2010 or earlier. You didn’t mention if the vehicle jerked anytime between August 2010 and June 2011? Codes and symptoms don’t always correlate and if the symptoms persisted you really needed to keep taking it back until it was diagnosed and repaired.

      I will say however that intermittent misfires are difficult to diagnose, which is why you were not charged. Another way to approach this would have been to say “we need to tear into this to figure out what is wrong, and we don’t know how much it will be until its apart and we know the exact cause of the misfire”. The problem here is that no one wants to ever hear “the truth” so instead lights are cleared and cleared and cleared until it is more obvious what is wrong. That is the Auto repair industry and it just wont ever change.

      Based on your post you have most likely had a valve issue since at least November of 2011 but unless I am missing something the cost to repair would be the same.

      Yes it does need to be repaired, not just because of the potential Catalyst issue but more importantly that misfires are hard on rod bearings as well.

      I know this doesn’t help take the sting out the estimate, but even though we have made this repair on a few Subaru’s it is not wide spread and I highly doubt you would have a second occurrence.


  22. Hi Justin,

    Someone linked to one of your posts on Subaru Outback Foums, and it sounds like the problem I have. The other day my car started running rough, but I have been noticing a drop in power for a while. (Not a big drop, but still not as much pep.) To make a long story short, my mechanic said that I have two burnt intake valves on the number 4 cylinder. (I live in San Diego, otherwise if I was up where you are, I’d take it to your shop. You really sound like you know what you are talking about.) From what you know, if I only fix one head, will I be ok for a while?

    Any suggestions would really be appreciated.

    1. Hi Joe,

      We usually check out both Heads most of the labor is in taking the engine out and getting it apart, once one side is off its really not much more time to take the other side off and be thorough. I will also suggest that the injectors need to be cleaned.


      1. Sorry I didn’t get back sooner, but I forgot how I got to your site. The shop did offer to pull the other head, but since I am going into the hole to get one side fixed, and I was thinking about selling the car, I passed on the other side. The mechanic said the compression on the other side was like new, so maybe I got away “cheap” this time.

  23. one more thing, the cel came on about 1 month ago. for the last few days, the car wont fire up right away, it will crank fine just not fire up. this never happened before the cel.

  24. I have a 05 legacy gt with 55k miles. misfire in cylinder 2, P0302 and P0000. changed injector and swapped injector, swapped coil packs, new plugs (oem). Dealer claimes the valves have zero clearance. Another shop did a leakdown test and everything looked good.

    car runs fine, the idle is not the best, but which subaru is?

    1. Actually modern Subaru’s idle just as smooth as any other car out there. If the valves clearance is out of spec than most likely one or more of the sodium filled Exhaust valves has burnt. Which causes the stem to become closer to the mechanical lash adjuster and then the cam shaft.

      It will continue to get worse, and if not repaired the valve can and will chip and break apart resulting in catastrophic engine failure that will result in a potential huge Expense (we have seen it happen), the cost can be controlled now if you repair it, but if you drive it until the valve fails and it destroys the engine you can be north of 8k in expense where you should be under 3k now.

      Further more I would ask when did the problem first show? Was it under the 5 year 60k power train warranty?

  25. Justin –

    I recently bought a 2005 LGT 5MT and have been trying to fix a rough idle (no roughness when I’m driving). So far I’ve replaced the plugs and used various fuel injector cleaners from the parts stores. Neither seemed to work. No CEL either. My two questions:

    Based on what customers have told you, how long is the timeframe between a rough idle and a CEL appearing?

    Also, will an OBD scanner show trouble codes even if the CEL is off?

    1. Hi Matt,

      I would start by connecting a vacuum gauge when cold and look for unstable vacuum reading, perform an injector balance test, then remove the valve covers and check the valve clearance in order to diagnose the issue.

      I would perform all of these tests cold.

      Its tough to put a time line to it as everyones perception is so different, sometimes we point out issues that customers are completely unaware of and other times the driver is so in tune to every noise, shimmy and shake they will become hyper critical of there car as it ages.

      Hope that helps


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