Squeeling pig sound - bad pulley??
Thread Starter
TECH Veteran
Joined: Aug 2002
Posts: 4,055
Likes: 1
From: Hartsdale, NY
Squeeling pig sound - bad pulley?? Before my head and cam change my motor squeeled like a pig. After the head and cam swap it still squeels. From everthing I can tell, the sound is comming from an accessory pulley.
Some times the sqeeling is there, other times it is not; it does not vary when the AC or power steering is used, however. It really does not vary with the RPM either. It seems to be louder after a car wash or rainy day.
I have changed the following pulleys/parts with no help:
1. Power steering (new pump w/ old pulley pressed on)
2. Main idler tensioner pulley - pulley only (Thunder Racing unit with larger pulley shoulders - same main tensioner was re-used)
3. New belts (AC and main belts)
4. pulled the crank pulley and re-installed the stock unit after cam change (no difference in squeel)
5. New H2O pump (no change in squeeling)
I have a stethascope and I placed it on all the pulleys when the motor is on and the squeeling is ocurring. Unfortunately, I can't definatively identify the bad pulley or other cause. I suspect it is the AC tensioner pulley, however. I am assuming the two tensioners (not the tensioner pulleys) cannot make the noise since they only hold the pulleys with a spring-loaded arm; right?
Any other thoughts on how I should try to identify the mistery squeel?
Thanks...
Some times the sqeeling is there, other times it is not; it does not vary when the AC or power steering is used, however. It really does not vary with the RPM either. It seems to be louder after a car wash or rainy day.
I have changed the following pulleys/parts with no help:
1. Power steering (new pump w/ old pulley pressed on)
2. Main idler tensioner pulley - pulley only (Thunder Racing unit with larger pulley shoulders - same main tensioner was re-used)
3. New belts (AC and main belts)
4. pulled the crank pulley and re-installed the stock unit after cam change (no difference in squeel)
5. New H2O pump (no change in squeeling)
I have a stethascope and I placed it on all the pulleys when the motor is on and the squeeling is ocurring. Unfortunately, I can't definatively identify the bad pulley or other cause. I suspect it is the AC tensioner pulley, however. I am assuming the two tensioners (not the tensioner pulleys) cannot make the noise since they only hold the pulleys with a spring-loaded arm; right?
Any other thoughts on how I should try to identify the mistery squeel?
Thanks...
On The Tree
Joined: Dec 2003
Posts: 179
Likes: 0
From: Bloomington, MN
here's one for you, try removing the oil fill cap and see if the noise goes away,,i had a car that had a mystery squeal and it turned out to be a vacume leak from one valve cover gasket [there's alot of vacume in the crankcase with no load]
good luck.
good luck.
Thread Starter
TECH Veteran
Joined: Aug 2002
Posts: 4,055
Likes: 1
From: Hartsdale, NY
Really? Thanks; I'll try that.
Would this only identify a vacume leak in the passanger side head or will removal of the filler cap equalize both sides?
What other symptoms does a vacume leak have; the car runs great and pulls hard?
When I had the heads off , I obviously removed the valve cover gaskets; since they are re-usable I just bolted them on again... Since the car squeeled BEFORE the head and cam swap I am inclined to suspect the plastic intake manifold leaks rather than the valve cover.... In addition, the new heads are milled .055 which changes head/intake alignment slightly....
Come to think of it, the squeeling did occur a few months after I installed a new LS6 intake manifold; do you suspect the gaskets on that unit are bad?
Do the valve covers and the intake manifold pull the same vacume?
Thanks...
Would this only identify a vacume leak in the passanger side head or will removal of the filler cap equalize both sides?
What other symptoms does a vacume leak have; the car runs great and pulls hard?
When I had the heads off , I obviously removed the valve cover gaskets; since they are re-usable I just bolted them on again... Since the car squeeled BEFORE the head and cam swap I am inclined to suspect the plastic intake manifold leaks rather than the valve cover.... In addition, the new heads are milled .055 which changes head/intake alignment slightly....
Come to think of it, the squeeling did occur a few months after I installed a new LS6 intake manifold; do you suspect the gaskets on that unit are bad?
Do the valve covers and the intake manifold pull the same vacume?
Thanks...
On The Tree
Joined: Dec 2003
Posts: 179
Likes: 0
From: Bloomington, MN
did you try removing the oilfill cap? did the noise go away? if the squeal went away then you hane a vacume leak to find it spray brake cleaner at suspected areas[valve covers,intake where it meets the head also there is a round piece where your map sensor is connected it is secures withn a o ring i have seen them leak vacume on occasion i allways smear some silicone around it when i do intake swaps. also to eliminate accessorys and pullys just take the belt and fire it up breifly this test could lead you in a new direction. good luck
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Thread Starter
TECH Veteran
Joined: Aug 2002
Posts: 4,055
Likes: 1
From: Hartsdale, NY
I haven't tried removing the oil filler cap yet.
Dump question: If I spray the suspect areas with brake cleaner (will silicone work too), how does this detect a vacume leak? Do you see bubbles around the leaking area?
I also installed an oil catch can in the PVC system; is this often a cause of vacume leaks too? I beleive the screeching started after I did the LS6 intake swap but before the oil catch can, new heads, new cam, etc.
If it does not have a vacume leak, I suppose I will replace the AC tension pulley. They cost $80 from the General (what a ripp off)
As retaliation, I will participate in the piston slapp class action litigation (tit for tat); right?
Dump question: If I spray the suspect areas with brake cleaner (will silicone work too), how does this detect a vacume leak? Do you see bubbles around the leaking area?
I also installed an oil catch can in the PVC system; is this often a cause of vacume leaks too? I beleive the screeching started after I did the LS6 intake swap but before the oil catch can, new heads, new cam, etc.
If it does not have a vacume leak, I suppose I will replace the AC tension pulley. They cost $80 from the General (what a ripp off)
As retaliation, I will participate in the piston slapp class action litigation (tit for tat); right?
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