Hello

I have bought a C5 a couple of weeks ago and I have a squealing noise from the engine. Its worst when you cold start it and then goes away as the engine gets warm. In the beginning it went away completely (I think) but now I can still here it when I give it a bit of gas and the rpm is a bit higher. Doesnt need to be very high, I can hear it over about 1500 rpm.

How can I determine what it is? Are there any risks with this noise?

 

Check the harmonic balancer for wobble.
It could also be a weak belt tensioner or bad idle pulley.

 

Thanks for the answer. Okey. But you dont think it could be one the belts?
Are those parts easy to change?

 

I had a bit of a squeak and thought it was a belt but it turned out to be a leak from the water pump getting coolant on the belt which caused the squeak.

 

Harmonic balancer .. get your wallet out if it is

 

Sounds like you may want to get the car checked over by a trusted mechanic so that you can determine exactly what the problem is. Any of the things mentioned above could be the cause.

 

Okay. Any ideas what we are talking moneywise to change one of the above?

 

It cost me about $600 parts and labor to have an independent shop install a new balancer and serpentine belts. Dealer quoted $900. The belt tensioner and pulleys are much cheaper to replace. The symptoms you describe are exactly what I was getting from a bad harmonic balancer. It's a very common issue that affects almost all C5s sooner or later.

 

Your description of the squealing was exactly the same as mine. Take the belts off one at a time. (that is, take a belt off, start the engine and listen; if the noise continues, turn off the engine remove the second belt and replace the first one and start the engine again) If the noise stops, you'll have found narrowed your 'field of error' to one of the two pulley systems. You'll need a 15mm socket and a breaker bar to release the tension on the tensioner pulley on either system to remove a belt.

The members on this forum helped me fix mine while I was away from home on a road trip. The solution was pretty simple because mine was neither the water pump nor the harmonic balancer--and since I knew the balancer was brand new my worst possibility was the water pump--but expense-wise, I got lucky, and my problem was just a tensioner pulley.

You (or your mechanic) will have to go through the exact process I did to find the source of the squealing, including buying and replacing each "suspect" part until the correct one was found. There's just no cheaper way around it; each pulley needs replacement once the "bad" pulley system is isolated in order to figure out exactly which one is bad... fortunately, the pulleys aren't real expensive.

The thread below is basically a step-by-step guide on how to narrow down the possible culprits:

https://www.corvetteforum.com/forums...squealing.html

Reading the thread will take more time than the actual physical work; and it's not hard to do at all. Good luck. Hopefully, it's not the water pump or harmonic balancer but you won't know until you replace the pulleys with new ones and install the belt--if it still squeals, the only source of noise is that that you haven't replaced with a new part.

Also, to temporarily stop a squealing belt, you can spray it with water. If that stops the squealing, you've really lucked out--belts are the cheapest items to replace.

 

Put a chalk or some sort of marker line on the inner and outer parts of the balancer, crank it up, make it squeal, shut it off. If the line you made is mismatched that's your problem.
Mine never showed any wobble but did squeal right before it tried to eject its outer ring. The steering rack prevented it from leaving the car.

 

The water pump on these is easier than it looks to change if that is what is wrong.

 

Okay. I will see if I can find out whether it is a belt or something else, in which case I will leave it to a mechanic next week. Is the car fine to drive until I get it fixed? I use it almost everyday

 

If it's not the water pump, you've got a little time--it all depends on what your definition of "until" is, and your tolerance for abusing worn-out parts.

 

I haven't tried spraying with water yet but had a look when I started it and couldn't see any wobble anywhere. But I dont know if I looked in all the right places. It sounds like it's comes from The passenger side, maybe the middle but I Sure thought the sound was higher from the passenger side.

 

Does anything change when you turn the A/C on or off?

 

not really, the Rpm changes slightly at idle but thats pretty normal.

I have however noticed a change in the temperature. I have (accordingly to the previous owner) an updated coolingsystem and it used to be spot on 190 F all the time, barely moving even in
heavy traffic.

​​​​​​​But the last 2 days I have noticed it being higher when moving very slow, today as high as 225 when I was sittning in traffic, but no problem keeping the temperature when moving faster.

 

Possible fan failure.

 

...Guess I'll have to Deal with that too then

 

Bet its the idler pulley my truck makes the same noise when they go out. Get a high quality one if you can find it many replacements (like dayco) say made in canada but the bearing is chinese it will go out fast.

 

I can't speak for others, but my Vette runs between 200 and 230, especially in the summer. Mine is an 03 and I've owned it since 05, so this has been the norm. The higher temps generally correspond with summertime traffic... You can easily tell if there is a aux fan problem - start the car and let it idle for a while. The electronic fan will come on.