I am working on a 2000 Grand am in the shop I work at and it has a rattling noise when brought of idle ,which seems to be up high in the engine , not a rod type knock , seems to run fine without no missing . We have changed the lifters (which I knew would not help us ) and timing chain and it is still noisy . I checked the plugs and number one was wet and all the others were fine , tried changing the coil pack assembly to see if maybe something was causing it not to fire #1 but sound still exsists . When listening with a stethascope the boss figured the injectors were noisy so we changed those and same thing still . The sound seems to be coming from under the coil pack assembly and is hard to pinpoint what cylinder exactly . Has anyone ever delt with this type of problem ? How do I fix it ?

I am working on a 2000 Grand am in the shop I work at and it has a rattling noise when brought of idle ,which seems to be up high in the engine , not a rod type knock , seems to run fine without no missing . We have changed the lifters (which I knew would not help us ) and timing chain and it is still noisy . I checked the plugs and number one was wet and all the others were fine , tried changing the coil pack assembly to see if maybe something was causing it not to fire #1 but sound still exsists . When listening with a stethascope the boss figured the injectors were noisy so we changed those and same thing still . The sound seems to be coming from under the coil pack assembly and is hard to pinpoint what cylinder exactly . Has anyone ever delt with this type of problem ? How do I fix it ?
no but if you find out let me no i have the same problem with my 2000

what engine?

I had a noise that was up near the timing chain/camshaft. It was caused by the bearings in the water pump. Too bad we found out after checking the lifters...
It could also be something on the accessory belt.
The sound travels right through the accessory belt and/or timing chain to the top of the engine.

I cant believe I never put what engine this thing had ! Its a 2.4 and I have new information. We put the thing up on the hoist and I had one of our guys start it and I listened underneath and its louder under the car and its coming from the pan , its more of a rattling noise than a rod knock. We decided to pull the pan and found what looks to be alluminum shavings in the pan . I looked a bit further and found a chain drive from the crank (rear) to what seems to be the oilpump/balance shaft assembly and this chain is REAL loose and could possibly be the culprit of the rattling noise but we still have to find the source of the alluminum shavings and look further into the noise problem.

I cant believe I never put what engine this thing had ! Its a 2.4 and I have new information. We put the thing up on the hoist and I had one of our guys start it and I listened underneath and its louder under the car and its coming from the pan , its more of a rattling noise than a rod knock. We decided to pull the pan and found what looks to be alluminum shavings in the pan . I looked a bit further and found a chain drive from the crank (rear) to what seems to be the oilpump/balance shaft assembly and this chain is REAL loose and could possibly be the culprit of the rattling noise but we still have to find the source of the alluminum shavings and look further into the noise problem.
if you find out can you let me no