All Wheel Drive Auto: Independent Seattle Subaru Service


Subaru Timing Belt Idlers part II


Today at the shop we had a later model Subaru Impreza Outback Sport come in on a Town truck it had died on the Freeway in the rain and would not restart.

We did our initial Diagnoses and came to the conclusion that the timing belt had failed in some way, but it wasn’t until we removed the timing covers and the belt that we knew the extent of the damage and also the cause.  Once we had it apart we learned that the geared timing belt idler seized, causing a majority of the teeth to strip off of the belt when this happened it caused extensive valve train damage to the point where the repair bill is very expensive and the idler that wasn’t replaced will have to be replaced now anyways, so what was saved?  The vehicle now has 150k, so the idler lasted another 35k post timing belt replacement but had it been done along with the rest of the idlers and the tensioner the driver would have a completely different outlook right now.  Car makers DO NOT inform about the real costs of car ownership, no one would buy them.

The timing belt had been replaced at the proper 105k schedule, but the job was incomplete.  Part of replacing the timing belt is inspecting, and advising on the condition of the timing belt tensioner and timing belt idlers as well as the water pump and any seals.

If the timing belt idlers & tensioner are not done with the timing belt my question is always when?  The warranty and maintenance booklet states the belt should be replaced at 105k, but leaves out everything else, it’s up to the Service provider to try and explain sometimes to deaf ears about the other needs, the service procedure is to replace the belt and inspect the timing components, once inspected and found to be noisy, or that they have a 105k on them and there’s a significant chance that they won’t last another 105k.  The condition of idlers, tensioner water pump and any seals should be presented to the car owner, if done there won’t be issue if good parts are used, if not its gambling and nothing short of.

There is no cause to go back into the timing covers for another 105k, or unless a noise is observed, but I can tell you it’s next to impossible to hear the timing belt idler from the driver’s seat while on the freeway in the rain, and the guys at the local lube center really have no idea what’s normal or not in terms of listening for noises..

I took some quick pictures for the Web Album below; as I have more time I will post some better pictures.


5 Responses

  1. I need a clutch in my 2003 forester with 66,000 miles. Should I use OEM parts and should I have the shop do a timing beltas long as they are at it. Love you blog – out here in denver.

    1. Hi Jamie,

      There is an updated clutch set you should use its only available from Subaru.

      The timing belt is due at 105k, and a totally separate job from a clutch replacement, there would be no savings in doing them both at the same time.


  2. I wish I lived closer to you so I could bring my 2003 Forester in for service. I live in NJ and have few options for expert service. I have 93,000 miles on her and the head gasket is leaking anit freeze. I want to get a full service – head gaskets, clutch, timing belt, tensioner and idlers, and an oil separater as you recomend.
    The big question is do I use subaru parts or are the after market brands better. My biggest concern is the head gasket – there are many after market brands claiming to be the best ( all seem to claim to be better then subaru ) What do you recomend?


    1. Hi Dave,

      We offer a Comprehensive kit, including the Six Start MLS gasket for your application. When we make the repairs here we use a combination Of O.E. Subaru Parts,those who make the parts for Subaru and lastly a few Aftermarket parts such as in the case of the Head gasket.

      I have tried everything out there using our Subaru service loaners as Guinea pigs, everything we tried lasted abut a year until we switched to the MLS gasket we now use, as far as I am aware it is the Only MLS gasket offered for the SOHC Subaru engine.


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