Please help me track down this engine/exhaust sound
Thread Starter
Le Mans Master
Joined: Dec 2000
Posts: 5,348
Likes: 3,319
Please help me track down this engine sound
Update:
I wish I was better at describing sounds. I bet there are plenty of people on this board that would recognize instantly what was going on if they heard the sound.
The best I can come up with is that it sounds like a cross between a belt slipping and the whine from a blower (although a lot quieter than both). There is a slight "squeakiness" to it. I think I was going with an exhaust leak as it varied so directly with engine speed and at idle there is a bit of a puling to it. It isn't as squeaky as brake pad wear indicators.
It varies with engine speed and is totally unrelated to the drive train and load.
With detailed location listening it appears to be coming from above the water pump, perhaps from the tensioner pulley there. Do the bearings in the pulleys go bad? I have images of a pulley seizing, belt bits everywhere, far from home, dark, cold, nearby wolves licking their chops...
Thanks for the help!
.................................
Last night, I noticed a new subtle sound from the engine that shouldn't be there. It is a small whooshing noice that increases in volume and pitch with throttle. I think it is a small exhaust leak.
Where I should I start looking and what should I suspect?
(2001 Z06, stock manifolds and exhaust)
Thanks!
Ehrich
I wish I was better at describing sounds. I bet there are plenty of people on this board that would recognize instantly what was going on if they heard the sound.
The best I can come up with is that it sounds like a cross between a belt slipping and the whine from a blower (although a lot quieter than both). There is a slight "squeakiness" to it. I think I was going with an exhaust leak as it varied so directly with engine speed and at idle there is a bit of a puling to it. It isn't as squeaky as brake pad wear indicators.
It varies with engine speed and is totally unrelated to the drive train and load.
With detailed location listening it appears to be coming from above the water pump, perhaps from the tensioner pulley there. Do the bearings in the pulleys go bad? I have images of a pulley seizing, belt bits everywhere, far from home, dark, cold, nearby wolves licking their chops...
Thanks for the help!
.................................
Last night, I noticed a new subtle sound from the engine that shouldn't be there. It is a small whooshing noice that increases in volume and pitch with throttle. I think it is a small exhaust leak.
Where I should I start looking and what should I suspect?
(2001 Z06, stock manifolds and exhaust)
Thanks!
Ehrich
Last edited by Elk; Jul 24, 2004 at 07:33 PM. Reason: New improved info!
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Ehrich
I have a mechanics stephoscope and it is EXCELLENT for pin pointing noises like this one. You san also use a L O N G screw driver to find noises! Set the tip of the screwdriver on a suspected noise source and the handle end on the little flap of skin that you put your finger on to close off your ear canal. The noise will travle up the screwdriver to your ear.
Go to each pully and driven componet until the noise is found!
BC
I have a mechanics stephoscope and it is EXCELLENT for pin pointing noises like this one. You san also use a L O N G screw driver to find noises! Set the tip of the screwdriver on a suspected noise source and the handle end on the little flap of skin that you put your finger on to close off your ear canal. The noise will travle up the screwdriver to your ear.
Go to each pully and driven componet until the noise is found!
BC
Thread Starter
Le Mans Master
Joined: Dec 2000
Posts: 5,348
Likes: 3,319
Excellent suggestions!
I've checked some more and it really does appear to be coming from the pulley/pulley assembly.
Do the pulleys/bearings in the pulleys actually go bad? I would think they would last essentially forever.
I'd hate to be replacing parts that won't solve the problem.
Thanks!
I've checked some more and it really does appear to be coming from the pulley/pulley assembly.
Do the pulleys/bearings in the pulleys actually go bad? I would think they would last essentially forever.
I'd hate to be replacing parts that won't solve the problem.
Thanks!
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
There have been people in the past who have had BAD tensioners! It is not uncommon but it is also not one of the TOP TEN C5 failure items.
Your best bet is to use the screwdriver, long metal rod ect ect method of listening to the assembly when it is spinning with the belt on and then removing the belt and examining the pully and bearing assembly for looseness, roughness when you spin it and slop.
Some bearings will only show signs of damage when they are put under load, so examining it with the belt off is not 100% fool proof.
Bill
Your best bet is to use the screwdriver, long metal rod ect ect method of listening to the assembly when it is spinning with the belt on and then removing the belt and examining the pully and bearing assembly for looseness, roughness when you spin it and slop.
Some bearings will only show signs of damage when they are put under load, so examining it with the belt off is not 100% fool proof.
Bill
