[BudaZ06]

I've used this forum for some very helpful information over the past two years but this is the first time I've posted a comment or question.

I hope someone can help me to identify the source of a loud squealing noise coming from my 02 Z. I live in Hungary and the nearest trusted Chevrolet dealer is a two hour drive to Vienna, Austria.

The loud squealing noise starts when the coolant temperature reaches about 160 degrees. We got under the car this weekend and the noise appears to originate from inside the flywheel housing. We removed the two small side inspection plates on the flywheel housing and the noise got noticeably louder. The noise seems to be unaffected by using the clutch or putting a load on the car. Once the engine gets to 200 degrees the squeal is intermittent. It's there at one traffic light and then quits one block later when I stop for the next traffic light.

Does this sound like the throwout bearing? Is there anything I can do short of replacing it?

My car has only 4500 miles on it. The first driving event at the Hungarian Formula 1 track is in one month.

Thanks for any helpful troubleshooting advice.

 

[IT L GO]

IMO if it was the throwout bearing the noise would either go away or change when the clutch is depressed. :cheers:

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[COUTO1981]

I say if you dont figure out by then, you will at the event when the bad part gets stresses and gives in, But thats problably dangerous and bad advise :blush:

 

[BudaZ06]

IMO if it was the throwout bearing the noise would either go away or change when the clutch is depressed. :cheers:

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I was wondering the same thing. Would the pilot bearing start squealing once heated? Another thought: the noise does change with rpm.

 

[Terry S]

I was wondering the same thing. Would the pilot bearing start squealing once heated? Another thought: the noise does change with rpm.

With the clutch pedal out the pilot bearing does not rotate. So if the pilot bearing is the culprit the noise should only be present with the clutch pedal depressed.

 

[BudaZ06]

With the clutch pedal out the pilot bearing does not rotate. So if the pilot bearing is the culprit the noise should only be present with the clutch pedal depressed.

Can you tell I'm not a mechanic? It's a learning process...

 

[NETfiend]

Does the car have to be moving for you to hear the noise???? i.e.. If the car is stopped and the clutch has been in for about 10 seconds is the noise still present? If the noise goes away when you do this, then it could possibly be the throwout bearing.. If not, continue reading....

You probably are going to need one of those car stethoscopes to isolate the noise. I'm betting it will probably end up being something in the lines of a bearing on one of the accessories is the culprate. An easy test is to warm up the car until the noise appears, then turn off the engine and take off the serpentine belt and see if the noise goes away. If the noise stops, my guess would be the A/C pump or the water pump is probably going out (most common). If the noise stays, everything else it could be is probably going to require the engine to be pulled or disassembled in some form (crank bearing, cam bearing, oil pump bearing). What does your oil pressure look like, is the oil overfilled?

If it is a bearing inside of the engine DO NOT CONTINUE DRIVING IT until the problem has been found/fixed. It would really suck to damage your block because of a bad bearing. Also, you should consider replacing the oil pump if this turns out to be the problem (the problems root cause could be a failing oil pump).

I would also consider changing the oil and putting in a magnetic drain plug (look for metal particles suspended in the oil). Some good oil could make the noise go away. What brand and weight of oil are you using, also, is it synthetic oil?

 

[BudaZ06]

The squealing noise will start with the car sitting in neutral at idle, and it will continue even after putting it into gear and driving the car. I haven't held the clutch in that long to see if the noise persists.

The oil pressure hangs just under 40 psi on the gauge. I haven't noticed a change in oil pressure--at the gauge--since the car was new. I filled it with Mobil 1 5w-30 to the full mark and then added an extra quart prior to the last track event in September. The car has been basically sitting in the parking garage since then--perhaps 300 miles on this oil.

I'm going to perform more troubleshooting this weekend even though I really hate to run the motor at this point. But what can I do. I'll disconnect the serpentine belt. I'll also try to send a sample of oil for analysis before changing it.

Thanks for the help.