In Reply to: Re: Timing chain posted by Kevin on December 20, 1999 at 00:23:08:
: On some start ups my car sounds like a diesel engine but then the noise goes away after 10 15 seconds. I have 95k miles and I push my car hard alot. Anyone know what this sound could be??
its the timing chain tensoiner,depending on where the engine stops there can be residual pressure on the tensioner side of the timing chain buy the exhuast cam trying to turn backward under valve spring pressure this will push the hydraulic tensioner piston back (usually worse when car is parked nose uphill/or left in gear).wear on tensioner piston and sleve assembly over time will also make problem worse ,this assembly can replaced without teardown of engine (you can see outside of tensioner assembly on right side of timing chain cover in front of exhuast manifold,should have a rubber plug on the end of a bleeder screw sticking out)a little mechanical knowledge is useful when doing this job though.so when you start the car the tensioner is loose until oil pressure builds up and put tension on chain until that happens the timing chain is slapping around in there and thats the noise you hear this is not good for the chain or all the guides and rails which is why they should be replaced at around 90k.