My engine has just started to make a weird whining noise when it is cold. When it is warm, however, the noise goes away. At first I thought it was the new timing belt that had just been put on, however, when I had a mechanic check it out, he said that the belt was fine and the right tension.

Secondly I thought it might be the bearings. Had the mechanic check these out, and he reckons that he has not seen better bearings on a second hand, imported engine.

The mechanic could not find the problem (even though he had my car for a whole day) . He did, however, tell me that the noise was coming from around the bottom of the sump somewhere.

Could the noise be caused by a faulty oil pump?? We had a bit of a problem with oil pressure when the front cut was installed, however, the problem was fixed (so I thought). This noise is really pissing me off, and I am worried that it will cause serious damage to my engine. I suggested this to the mechanic and he said that it could be as there is a hint of tappet noise as well.

Any thoughts on the matter would be greatly appreciated. My final resort will be to take it to the local Mitsi dealer, however, I would rather not.

 

The noise could be a lot of things. If it's cold then it may be a bearing in anyone of the accessory on the front of the engine.
Alternator, P/S Pump, A/C? Idler pulley, Tensioner Pulley?

If your mechanic can't find it, he is not very good. It is not that difficult. Take the belt off and run the car cold for no more than 15-20 seconds and see if it's there. If it's gone then you just need to figure out which one it is coming from. If it is stil there then it could be in the timing belt. There is more tension with a new belt and any belt tensioner bearing or Water Pump (don't know if that is Timing belt driven?) can cause the noise. If it is belt driven though I hope you relaced the water pump with the belt!

Alternator is one of the biggest culprits of a whine. Usually when they are on there way out.

 

I have had the bearings in the pulleys checked out and they are perfect. One thing I have noticed, is that the noise increases/decreases depending on the amount of throttle.

Another thing, the new timing belt had been on for a while before this noise appeared. This makes me think that it is not the belt.

Also, why is it necessary to replace the water pump if a timing belt exactly the same as the one being replaced is used?? Do they do this every time timing belts are replaced??

 

Usually you do because, if I am not mistaken it is driven by the belt. If not then this means nothing. You already have it apart so might as well put it in. If it goes like 1000 miles later it sucks to tear it back down. Plus if it leaks it can get on the belt. It's just common practice.

Is it a factory timing belt and or serpentine belt? If it has cross-grooves in it it will make some nasty noise. I think it is Gates that makes that POS belt.

Again I question the alternator, they usually will make that type of noise plus they spin the fastest of all the accessories.

The oil pump I can only see if it is cavitating and getting air in it.

Removing the belt for 15 seconds or so is a good indicator too.

 

Thanks. Your help has been much appreciated. I will look into it and see what is causing the noise.

 

hey,
my cars makin the same noise, though my engines a 4g93 sohc versioin.... Tell me if u know whats wrong with it, that noise gives me the ****s!!

 

does your have a hint of tappet noise as well. Mine does, which makes me think that oil pressure isn't as high as it should be due to a faulty oil pump.

Any ideas??