Diagnosing underhood squeal
Thread Starter
Race Director
Joined: Jul 2004
Posts: 16,795
Likes: 62
From: Lake Havasu City, AZ
Diagnosing underhood squeal
My 2001 has developed an underhood squeal. It sounds like it only happens during rpm ranges from idle to approx 1800.
It is not wheel bearing related as it happens whether the car is moving or not. It is not belt related as I "soaped" it and the squeal remains.
Is there a common problem on C5's that I should check for first?
thanks
It is not wheel bearing related as it happens whether the car is moving or not. It is not belt related as I "soaped" it and the squeal remains.
Is there a common problem on C5's that I should check for first?
thanks
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
I can think of two, first is the tensioner and second is the crankshaft damper. Look at the damper and see if you can detect any wobble.
Never heard of soap on the belt, but if in question just replace it. Only takes about 2 minutes.
Never heard of soap on the belt, but if in question just replace it. Only takes about 2 minutes.
Safety Car
Joined: Aug 2000
Posts: 4,537
Likes: 84
From: St. Joseph MO
Cruise-In III Veteran
Cruise-In IV Veteran
Originally Posted by vettenuts
I can think of two, first is the tensioner and second is the crankshaft damper. Look at the damper and see if you can detect any wobble.
Never heard of soap on the belt, but if in question just replace it. Only takes about 2 minutes.
Never heard of soap on the belt, but if in question just replace it. Only takes about 2 minutes.
Instructor
Joined: Jul 2005
Posts: 122
Likes: 0
From: GERMANTOWN TN
Originally Posted by vettenuts
I can think of two, first is the tensioner and second is the crankshaft damper. Look at the damper and see if you can detect any wobble.
Never heard of soap on the belt, but if in question just replace it. Only takes about 2 minutes.
Never heard of soap on the belt, but if in question just replace it. Only takes about 2 minutes.
Go ahead and replace the belt, won't hurt anything.Hope you figure it out,
Blake
Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
While you have the belts off, check the tensioners and idler pulleys ..they shuld turn smoothly with very little resistance, and they can squeak when the bearings start to go in them.
Drifting
Joined: May 2005
Posts: 1,566
Likes: 52
From: Colorado Springs CO
Helpful links
I just changed my belts because I had the exact same problem. 3,000 miles later, everything is still nice and quiet. Used the gatorback A/C belt and the Kelly serpentine. Got them from Autozone for less that $40.00 total and replacement is easy. The links below are from forums discussing this that have some great advice and include the diagram of the belt placement so you don't have to worry about not remembering how it goes back on! Also tips on the easiest way to get them back on!
1st Forum Link
2nd Forum Link
Hope they help, it's a really easy do-it-yourself!
1st Forum Link
2nd Forum Link
Hope they help, it's a really easy do-it-yourself!
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Thread Starter
Race Director
Joined: Jul 2004
Posts: 16,795
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From: Lake Havasu City, AZ
Bought the new belts today( couldn't get the GY Gatorbacks without special order locally so I had to go with the lifetime guaranteed Dayco PolyCogs) and changed them out.... thanks for the tips especially to Bounty Hunter6 the links sure made the job easier than I expected. I was able to change both belts from the top of the car.....
The pulleys felt ok... I could not feel any rough spots on turning them.... but the next few days driving will tell the tale.
thanks again
rich
The pulleys felt ok... I could not feel any rough spots on turning them.... but the next few days driving will tell the tale.
thanks again
rich
Thread Starter
Race Director
Joined: Jul 2004
Posts: 16,795
Likes: 62
From: Lake Havasu City, AZ
hmmm, the squeal is back. I'll have to do a little more sleuthing...
I originally thought it was the A/C belt. when i poured water on it the squeal immediately went away.....
I changed the belts from the top so it was impossible to get a wire brush on the pulley.
I originally thought it was the A/C belt. when i poured water on it the squeal immediately went away.....
I changed the belts from the top so it was impossible to get a wire brush on the pulley.
Instructor
Joined: Aug 2001
Posts: 178
Likes: 0
From: Fayetteville AR
I have a similar "squeal" after the car warms up. It is certain RPM ranges and it almost sounds like it is coming from underneath the car. Can pulley's be deceiving on where the noise is coming from?
It does it at the same RPMS whether the car is in gear or not. There is no way I am taking it to the dealer so they can just start guessing as to what it might be.
any thoughts?
It does it at the same RPMS whether the car is in gear or not. There is no way I am taking it to the dealer so they can just start guessing as to what it might be.
any thoughts?
Last edited by SmoknLT4; Aug 29, 2005 at 01:21 PM.
Safety Car
Joined: Aug 2000
Posts: 4,537
Likes: 84
From: St. Joseph MO
Cruise-In III Veteran
Cruise-In IV Veteran
Originally Posted by rws.1
hmmm, the squeal is back. I'll have to do a little more sleuthing...
I originally thought it was the A/C belt. when i poured water on it the squeal immediately went away.....
I changed the belts from the top so it was impossible to get a wire brush on the pulley.
I originally thought it was the A/C belt. when i poured water on it the squeal immediately went away.....
I changed the belts from the top so it was impossible to get a wire brush on the pulley.
Instructor
Joined: Aug 2001
Posts: 178
Likes: 0
From: Fayetteville AR
Originally Posted by SmoknLT4
I have a similar "squeal" after the car warms up. It is certain RPM ranges and it almost sounds like it is coming from underneath the car. Can pulley's be deceiving on where the noise is coming from?
It does it at the same RPMS whether the car is in gear or not. There is no way I am taking it to the dealer so they can just start guessing as to what it might be.
any thoughts?
It does it at the same RPMS whether the car is in gear or not. There is no way I am taking it to the dealer so they can just start guessing as to what it might be.
any thoughts?
I am beginning to think that my squeal might be pulley/belt related. Does anyone know if the noise can sound as if it is coming from underneath the car or is it only noticeable at the pulleys? When mine squeals, you can stand right over the engine and it sounds like it is coming from under the car. Has anyone else experienced this?
Thread Starter
Race Director
Joined: Jul 2004
Posts: 16,795
Likes: 62
From: Lake Havasu City, AZ
Mine clearly is the A/C clutch. After using soapy water and isolating the noice to the A/C belt system... I removed the belt and hand spun the idelr pulley, the tensioner pulley and the clutch pulley.
the idler and tensioner spun smoothly and continued spinning for seconds....
the clutch pulley felt gritty and I could hear a grinding sound at low rotation speed. When I tried to spin it, it would stop immediately and I could hear a slight screetch even at hand spinning speeds!
the idler and tensioner spun smoothly and continued spinning for seconds....
the clutch pulley felt gritty and I could hear a grinding sound at low rotation speed. When I tried to spin it, it would stop immediately and I could hear a slight screetch even at hand spinning speeds!
