Timing case knock

[lolcantturn]

Hey yall,

I have a M20B27 and I have this strange knock that APPEARS to be from the timing case. The car got a timing belt job done professionally about 6 months ago but hasn't been driven much since. I dont suppose this is rod knock or a bottom end issue, the engine drives with plenty of life and there is no abnormal smoke. It might be something loose rattling around in the timing case?? I can feel the knocking when I put my hand against the intake manifold.

Also, it doesn't happen when its cold. Only when its been fairly warmed up. The fact that the knock audibly goes away at higher RPMs makes me think centrifugal force is holding "something" in place.


Thoughts?

[ForcedFirebird]

There's a plastic timing belt window cover on the back of the aluminum timing cover. If it's there, pull it off and check if there's tension on the belt. If the mechanic didn't let the spring tension the belt (or left the spring out completely, seen it many times), then the belt will be too loose and will hit the cover.

Another thing to check is the brand of tensioner used, in case you didn't provide it. There's a cheap brand of tensioner I have seen used that goes bad very quickly.

Either way, since you had a professional do the job, take it back - they "should" warranty their work.

[lolcantturn]

There's a plastic timing belt window cover on the back of the aluminum timing cover. If it's there, pull it off and check if there's tension on the belt. If the mechanic didn't let the spring tension the belt (or left the spring out completely, seen it many times), then the belt will be too loose and will hit the cover.

Another thing to check is the brand of tensioner used, in case you didn't provide it. There's a cheap brand of tensioner I have seen used that goes bad very quickly.

Either way, since you had a professional do the job, take it back - they "should" warranty their work.

It doesn't *appear* to be too loose, I can get the belt to hit the cover with my fingers but it does take a little bit of effort. I will look into which spring tensioner brand he used.

Unfortunately, I can't take it back to the shop as I just drove this car from CA to PA.

[E30speed6]

look under the valve cover to make sure the rocker arms have retaining clips still on

[MrBurgundy]

Yeah, it sounds like the t belt tensioner. The belt should be super tight.