# engine nosie at low RPM's



## jordancrockett (Dec 23, 2007)

i have a '94 altima, and if you have it everyone has heard this noise. its like one of the belts is rubbing against something or something is going on at low RPM's, like 600 to 1200. I was looking at some of the Technical Bulletins that Nissan has posted and some other people have complained about this problem. I was just wondering if anyone else knew what was going on. Thank you for the help.


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## Altima SSS (Oct 10, 2007)

It could be:

a) cam chain or tensioner noise
b) belt noise
c) belt pulley noise
d) combo of a, b or c

My 94 is pretty quiet when it's started cold, but after it runs for ~5 min or more I can start to hear a noise at idle. I think it's the belt and/or belt tensioner. If I rev it up to about 2500~3000 it goes away. When it's cold outside I can't hear it as much.

I think a bad cam-chain or tensioners will make more of a grinding/chattering noise.

Give some more symptons -- like at startup, when warm and at RPM is it most noticable?


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## jordancrockett (Dec 23, 2007)

its like yours, but worse. it starts at start up and just keeps on going as it warms up, but like you said, goes away around 2500-3000+RPM.


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## Altima SSS (Oct 10, 2007)

jordancrockett said:


> its like yours, but worse. it starts at start up and just keeps on going as it warms up, but like you said, goes away around 2500-3000+RPM.


I think mine is the idler pulley for the alternator belt. I used a stethoscope on the pulley when the engine was running and it sounded noisy. Could be some belt noise too.

Only way to really verify is to remove both belts and start the engine up cold and listen to see if it's any different. Watch the coolant temp as the water pump would not be turning, but should be able to run the engine long enough to verify if the noise is internal or external.

If you do that test let us know what you found.


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