The engine makes a chirping/squealing noise above 2k rpms while driving when cold. It's not completely constant or extremely loud, but is noticeable. When it warms up, the sound goes away, which really confuses me. I have replaced both belts, and all four idler pulleys to no avail. The alternator, water pump, AC compressor, and PS pump all seem to turn smoothly. The car does not behave negatively, other than the noise. I cannot tell where the sound is coming from. Every once in a while, when I get in the car after it has been parked, I swear I smell a faint whiff of antifreeze, but it quickly goes away. There are no leaks anywhere, the engine runs cool, and coolant level is fine, so I'd like to think I'm dreaming. However, since the car is a 99 (only has 66k miles) I'm tempted to replace the water pump for good measure to see if this fixes the problem. Does anybody have any suggestions before I do that?

Update: I have replaced the water pump, both tensioners, all idler pulleys, and even had the alternator rebuilt because it's rear bearing started squealing during this whole process. I have removed the A/C belt altogether to eliminate the compressor as the source of the squeal. I am down to PS pump or internal engine noise. I have noted a slight wobble of the crank pulley at idle that smooths out as the engine revs. The squeal is now becoming louder, more constant, and is starting to appear at idle. I'm going to take it to either the dealership or a local speed shop, because I'm finally calling uncle. Incidentally, everything I've replaced so far seems to have needed replaced anyways, so my efforts have not been in vain. I'm afraid I'm hosed though, because I've never heard of a PS pump go bad, and the crank pulley wobble has me more than nervous. If anybody has supportive words of encouragement, I need them.

 

I have the same exact problem! Mine happens under acceleration...just around 2k...but goes away after the car is warmed up.

Like a squeaking/chirping noise. I assumed it was a belt or pulley.. But it looks like you ruled that out.
My car is going to ECS next Thursday for a header install and I'm hoping this noise happens while the guys are tuning it. If it surfaces and is diagnosed…I’ll post the outcome.

 

Sweet. Please keep me posted.

 

I had the same issue and the answer turned out to be the water pump. The impeller inside the pump is the squealing/squeaking noise you hear. When the engine warms up / coolant gets warm through the water pump, it goes away. I also replaced the belt,tensioner and pulley before finally replacing the water pump. And seeing my ride is ten years old, and everything is/was original, I didn't think twice. Also if you decide to replace the pump, I bought a Bosch LS1/LS6 pump on Amazon for $105....shipped. Hope this helps.

 

Mine was doing that two and ended up being my ac tenshioners. If you don't want to change it take one belt off at a time and run it for about a min not to long to over heat it. Or if belt is bad just cut it off I replaced the belts 3 times befor I said f... It and spent the 60 bucks for a ac tenshioner but I knew it was the ac be cause I did the belt removal one at a time. Hope this helps someone.

 

Darryl, thanks for the tip on the WP on Amazon. They only had 3 left, so I picked one up; good preventative maintenance for a 10y/o car anyway. BigthunderNos, did your sound go away after replacing the AC tensioner? I replaced the pulley on the tensioner, but didn't think to replace the whole tensioner. I guess if the WP doesn't fix the problem, both tensioners will probably be next on the list. Thanks for the prompt help guys.

 

Yes I just came in from doing it and when I got It off you could see rust coming from inside it and is chirp free.

 

Sorry BigThunder. I was on the phone while typing (not always good at multitasking). What I meant to ask you was whether your original noise went away after the car warmed up.

 

Sometimes, was there most of the time,it was driving me crazy because I seamed to here it at stop lights and everyone would stair at what sounded like a peace of crap

 

To pin point it take off Your ac belt and drive it and be for you do that take off the main belt and start it and run it for a min and see if it is the ac and you can make sure it is not your main belt. Hope that makes sense,I kinda dose in my head lol

 

No, I completely understand what you're saying; makes perfect sense. If the WP doesn't fix the problem, that will be my next step. Since the noise completely disappears once the engine warms up, I'm guessing my problem is most similar to Darryl's.

 

It very well could be. One more thing to try is if you can get it to do it you can spray the belts with water and see if it changes but could still be w-p

 

I hate to say this but I also ended up spraying the belts everytime I started the car up and it got to be a real pain in the ***. After changing the tensioner, pulley, and belt, in went the water pump and it seems to have solved the problem. And for you cheapskates out there like me, I also picked up a Goodyear Gatorback belt from Amazon for about $20.

 

See OP for updated. If anyone can think of something simple I'm overlooking, it will make my day.

 

Well I definitely wouldn't throw any more parts at it until you've isolated the problem... Do you have a mechanics stethoscope? If not pick one up at sears or an auto parts store and poke around with it to see if you can isolate the sound to one particular component.

Maybe one of the new pulleys you installed is defective... If you've run the car without the AC belt attached and the noise is still present you've eliminated both of those pulleys and that belt as a possible cause. Now try removing the drive belt and starting the car (running it for a short time without the drive belt on won't hurt anything).

Assuming you bought new parts and none are defective and they are all properly installed I'm thinking you might have a bad bearing on the power steering pump... Is your harmonic balancer wobbling noticeably?

 

The balancer is wobbling noticeably enough to see it; more than I feel should be normal. I like the idea about removing the belt and running the car. I'll give it a go and see what happens. As for a mechanic's stethoscope, I do have one in the form of a shop vac hose. The problem is, the squeal is so loud that it is hard to isolate actually where it is coming from.

 

My '99 had the same symptoms yours does. I think a new harmonic balancer is in your not too distant future. It appears to smooth out only because the wobble blurs - it's still there. It will get progressively worse. Don't put it off too long. If the outer pulley separates it could cause expensive damage to the rack and oilpan. Do a search.

 

LOL, nothing like homemade tools... The thing is, a store bought stethoscope has buds that fit in your ears that will block out some of the ambient noise. It won't block it all out, but when you touch the needle to a bad component the sound will be noticeably louder... might be a good investment. They're pretty cheap. I think I saw one at harbor freight for about five bucks, so you could order that...

If the noise doesn't go away when you run your car without the drive belt installed you've eliminated all of the bearings on that system (including the only one you haven't replaced yet, the power steering pump). If that's the case I'd remove the A/C belt one more time to make sure it's not a component of that system...

If you remove the AC belt and the squeeling stops (with both belts off) leave the A/C belt off and put the drive belt back on... If the squeeling resumes again you likely need to replace your harmonic balancer. It's the only component that is part of both systems so if the the noise is present with one belt on (either one) but not with both off that's likely the culprit. You want to MAKE SURE THIS IS THE ISSUE before you replace it as it is not an easy install. It involves removing the steering rack. You'll also need a tool capable of tightening the balancer bolt to 250 ft/lbs (that's from memory but I'm pretty sure it's right)... A chevy dealer will probably charge you parts plus 4 hours of labor for this if you elect to have a mechanic do it...

If you can isolate it to one specific belt system put a stethoscope on each of the components on that system... The one that screams the loudest is the winner. GL

Here is a link to one of the times Evil-Twin posted his diagnostic procedure http://forums.corvetteforum.com/1554851317-post2.html

 

I'll fiddle with it in the morning and report my findings. The good thing is that everything I have replaced appears to have needed replacing after I removed it. If they weren't causing the problem today, they would be tomorrow. Luckily, I don't have to add anger of needless repairs to my current sense of frustration. Basically, it sounds like I need to have the balancer replaced regardless, and I'll pull the belt in the morning to try and isolate the sound. I don't know why I didn't think to remove the main drive belt earlier. One way or another, I think it will be going to the shop, because I don't think I'm going to mess with the balancer due to lack of a puller and the fact that this whole process is really starting to burn me out.

 

Somebody tried telling you that a long time ago