I have a 92 SC300. Car has 160K on it.

Recently when I start it in the cold the car would make a chatter sound or what sounds like chatter. When I first start it for couple seconds then it goes away. It also happens when I accelerate at WOT or under hard acceleration.

What could it possibly be?

Could it be my belt tensioner bearing going bad?

Thanks and appreciate the help.

 

any help or ideas?

 

Would it be possible to take a video or sound clip of it? Could be anything from valve tap to piston slap or a bunch of other things. Also may not be a bad idea to pop the hood before you start it in the morning, and either have a friend start it, or start it and jump out to try to pinpoint where the sound is coming from. You can also take off the top timing cover and look for any irregular marks on the timing belt, generally a bad idler or pulley will create odd wear on the belt.

Notice any smoke from the exhaust during WOT?


Thanks,
Rick

 

Mine does that too, been doing it for 2 years now. When you start it goes CLACK CLACK CLACK and goes away ?

Its probably bearings not getting oil fast enough.

 

'll check the timing belt when I get home. I'll also do that other tip also.

Only smoke that comes out of the car is when i first start it, but I also have the 12v mod, so i dont know if it would make it smoke either. and the smoke goes away after its warm.

thanks

Did yours only do it when you first start the car?

My car has the chatter at start when cold, at WOT, along with hard acceleration. But doesnt do it when the car is idleing or crusing.

 

I didnt get to check the timing belt, since I misplaced my HEX set.

But i did have someone else start it when I was outside looking at the engine.

Is it normal for the serpentine tensioner to shake on first start up?

 

No, it is noy normal if I understand your description. The bearing for the tensioner may be shot.

 

Sorry "not" normal. Small phone keyboard ;

 

tensioner bearings make a whining noise when bad and will progress with speed. is your car sitting for long before the cold start? is it making noise from upper or lower part of motor, also front or rear

 

Stethoscope may be helpful.

 

I think the bearing is shot, when my car starts the tensioner moves and rattles until it gets steady, and when i rev the engine the tensioner moves quite a bit.

the car is sitting anywhere from over night to only an hr. its making it from the front.

 

remove the serp belt then turn the car on see if it makes the noise still

 

So, I was wondering would it be ok to just change the serp. tensioner pully with a new one? Autozone sells a new one with a bearing for $20.

 

So the noise is still there but not as noticeable, I'm going to be doing some maintence stuff to see if it helps.

I'm pretty sure the acceleration rattle is from the heatshields, since when i looked under the exhaust was bent.

 

sorry to bring up an old post but would just getting the 20$ tensioner pulley work the same as if i get the whole tensioner? i just need to replace the bearing not the whole tensioner but autozone doesnt sell the bearings alone.