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high pitch squeeling at idle

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Old 07-06-2010, 12:08 AM
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Sab
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Default high pitch squeeling at idle

I recently noticed a high pitch squeeling niose at idle at my '82 euro.

Thetiming belt was recently changed by a reputable shop and nothing else has really changed.
I disconnected all three belts up front one by one and no change, so it is not an issue with belts or alternator, air pump, power steering...
I placed a hose on top of the timing belt cover vent hole and don't hear it from there. Timing belt looks centered and does not seem to rub anywhere.
I can't really tell where it comes from, but seems at the front, but rear not out of the question.
Have a pretty bad oil leak at the rear of the engine, which is not pinpointed yet either.

The noise is only audible at idle, car runs strong and makes no noises under power.

What to do? Ignore it, take it to the track and drive it like i stole it, or reasearch further?
Any suggestions are greatly appreciated.
cheers,
Old 07-06-2010, 12:18 AM
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linderpat
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sounds like it might be the water pump. Was that changed with the tb?
Old 07-06-2010, 12:19 AM
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WICruiser
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Where the idler pulley bearings changed with the belt? I would pull the front covers and identify the noise souce before the belt is damaged.
Old 07-06-2010, 12:41 AM
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Mrmerlin
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was the oil pump o rings changed?? if so they may have not put the pump back together and it can seize in the block the outer ring gear has a dot stamped into it this dot should match with the drive gear and they both face towards the engine .
The water pump may also be suspect i would not run the engine any longer than to diagnose this noise as you could be causing catastrophic damage to the engine
Old 07-06-2010, 12:41 AM
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water pump was changed, I will talk to the shop to investigate what exactly was changed during the tb job.
Old 07-06-2010, 12:51 AM
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Mrmerlin
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without major disassembly you could rain the radiator at the lower plug then pour some of the coolant into a white bucket and see if can spot any mettallic particles they will be easy to spot do this inspection in the sun same goes for the oil get a piece of lamp coord put it into the dipstick tube
( the reason for the lamp cord is so you dont make more metal and get a false reading every time you pull out the dipstick it will grind on the tube and metal shards will come off).
and drip the oil onto a black piece of cardboard look at the oil in the sun if you see lots of metallic particles then you may have an oil pump getting ready to seize.
If both of these test are negative for metal then its quite possible one of the idler bearings may be rubbing on the waterpump securing bolts
Old 07-06-2010, 09:18 AM
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thanks for all the suggestions.
One more detail. It does not squeel at all when cold, just after about 5 minutes when engine is warmed up...
Old 07-06-2010, 11:04 AM
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davek9
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Any chance the noise is coming from one of the other systems in the front ?
Before going in, I would remove all the belts in the front of the eng, Pwr Steering, Alt, AC Comp, Air Pump (if still installed). You could also do them one at, start w/ the outer most and work your way in.
Start eng and listen
Old 07-06-2010, 07:28 PM
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rexpontius
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I believe thats what he already tried??
Old 07-06-2010, 09:16 PM
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yes, tried that already...
it's not the exterior belts or pulleys...
Old 07-06-2010, 10:22 PM
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If all of the above is good...I would check the smog pump if you have one on your car. I've seen 2 that were about to fail start with a squeal.....just a thought!
Old 07-07-2010, 09:39 AM
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the problem I am facing is that the squeel will only start when the engine is hot. So I am worried that if I take the car apart to look at the T-belt, it may not be apparent what makes the noise...
Is there a way to get a a listen to the water pump and oil pump while the car is running?

This is very frustrating, as I have a free open track day tomorrow and all is ready to go to run the car (besides the noise...).
Old 07-07-2010, 09:44 AM
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Ragnar Joensen
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The smog pump may run, even if You take of the belt. And the bearing can make bad sounds.

It will run because of the suction from the exhaust (I guess).


Ragnar
Old 07-07-2010, 11:04 AM
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davek9
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Sorry I scanned and did not Read this: "I disconnected all three belts up front one by one and no change, so it is not an issue with belts or alternator, air pump, power steering...".

Sab can you get a complete listing of the "new" parts that were changed w/ the "T" Belt service ?

But I would not drive it until you find out the source of the noise, if the belt breaks your looking at big bucks to repair the valves/heads.
Old 07-07-2010, 12:31 PM
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dprantl
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The noise doesn't go away when you press the clutch?

Dan
'91 928GT S/C 475hp/460lb.ft


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