So I have had the '99 FRC for about three months now, and Iam really enjoying the car except for this squealing that is continuing to get worse. The conditions are as follows:

- Only under engine load
- Intermitant (under light loads at ~1300rpm, 1500rpm, and 2000rpm but not present at other engine speeds)
- under heavy loads it is continuous and has a slight flutter correlating to the rpm
- sounds 'kind of' like belt squealing in sound pitch

About a month ago I replaced the stock harmonic damper with summit racing piece due to the 'wobble' that is typical starting to occur. It has a new belt, new idler pulleys, new tensioner pulleys. There are no modifications to the vehicle other than a k&n air filter element, and the b&b triflow cat-back exhaust (which has been on the car since new and the squealing began about a month and a half ago). I am probably getting hyper-sensative but it seems like there is excessive injector noise on cylinders 5 and or 7, though it could be completely unrelated.

I have also notice that the car is idling at 650-675rpm, and a bit on the lopey side. I don't remember if it was idling this low when I puchased it. The car has 50k miles on it.

Any help with this would be greatly appreciated!!! It's getting annoying!!!

 

It sounds a lot like a belt that is not tightened enough. Are you sure that: a) all the pulleys, dampers, etc., you replaced were the same diamter as the original and that the belt was the same length as stock, b) the the aftermarket damper had the same number of grooves as the original (some have more grooves than stock to faciliate winder aftermarket belt kits for superchargers, and people put the stock belt groves in the wrong pulley grooves and this makes the tensioning go wrong, and it squeals, c) that you tensioned it correctly?

 

Thanks for the feedback Lee, to respond to each:
a) I did make sure they were all the same diameter, etc. and the belt was ever so slightly smaller than stock due mostly to the old one being worn out with cracks starting on the grooves.
b) The Summit damper does have 8-ribs on the main serpentine section, but I have the belt on the outer 6 which line up with the system. The two additional ribs are machined towards the a/c drive grooves taking up the space that is available in reference to the OEM damper.
c) I'm not sure which 'tensioned' you are looking for; I used the old crank bolt and torqued to 240 ft/lbs, then set the new bolt at 37 ft/lbs and was able to go ~110-115 degrees before I had no strength left in me. The squealing was there though for almost two weeks before I replaced the damper. The belt tension is definately greater than the old belt. As a matter of fact, the tensioner only rotates about 0.75cm from max when the belt is installed. Perhaps being too tight could cause an intermitant squeal??

The frusterating part is that under light loads it will come and go and come and go several times as the engine speed increases. Then under heavier load (>50%), it is consistent and flutters relative to the rpm. At idle or just revving, it is not present.

I'm about to just take it to a dealer, but sometimes cars come back in worse shape! My vacation time is also up and I have 600 miles to drive tomorrow!!

 

Given all that I'd probably replace the Summit damper with a new stock GM one. I haven't had good luck with a lot of Summit stuff and haven't bought from them in years. Not saying it is a bad damper but given that most dealers immediately point to aftermarket stuff as the cause of all bad things and they will likely replace it as a first step if you take it there, it might be worth doing before hand.

 

JDS: Do you have a stethescope or a long screwdriver? Place that on the various components that the belt runs over,being VERY careful to not get caught in the belt! A had a clutch bearing go out on the AC pump and it squealed o lot like that. Also my daughters camaro was doing that and I hit the belt with a shot of WD-40 and it stopped. But that was a belt thing and you've pretty much eliminated that. Good Luck!
Ron

 

Well I did end up going ahead and stopping by the dealer. I wanted a second look before making a 600 mile trip back home. Lee I know an oem damper would be more ideal for a dealer inquiry, but after having replaced one of these things now and knowing the PITA it is I am just going to leave it. They did notice the aftermarket damper, but the tech there was pretty understanding and actually mentioned how the oem ones tend to go out pretty often on these... They wanted to believe it was the belt at first, but after a couple of test drives and getting underneath the car with a stethascope they discovered the source was coming from the front of the torque tube area. This means either the throw-out bearing or pilot bearing, and the tech was leaning towards the pilot but couldn't be sure without a costlyinspection. Looks like another unplanned Saturday is in order! It will have to be next Saturday though due to work.

Ron, I have definately done the long screwdriver a few times for this and more times than I can count in the past. My neighbor saw me doing it not long ago when this first started and thought I was crazy. I tried explaining that acoustics are a fluid transfer and air dampens it, but I had to get her to do it herself before she believed me. Good times.

Thanks for the responses, I'll post what I find when I get her quiet again.