itzjonjon69

So I've noticed that after driving the car hard and the temperature is at 200+ degrees when hitting the throttle at 900-1000 RPM you can hear a squealing noise and it's present all the way until the exhaust note takes over which then you can't hear it anymore. The odd thing is when you first start the car up (from cold start) and drive normal the squeal isn't there, but the moment the car is driven hard and 200+ degrees the squealing appears whenever the throttle is pushed/touched.

Has anyone experienced this before? Could it be the serpentine belt?

***also*** i also get a squeaking noise at cold start when the the turning wheel is turned all the way, but once warmed up that noise is gone

Mort

Your throttle squeak may be the accessory or idler pulleys. There are a few posts about them wearing out. Weistec makes replacements as well that you can check out.

http://weistec.com/all/c/c-63/2008-2...r-pulleys.html

The squealing noise you hear when turning at cold start up is the pressure relief valve in the power steering. The cold fluid does not flow as well and the excess pressure in the pump is causing the relief valve to open. This is not good for the pump and if you hear it back off the steering a little untill it goes away. Might not hurt to change out the fluid with a suction device (turkey baster) and top it off with fresh fluid. You might have to do it again after driving a bit as you will not be able to get all the fluid out at once.

itzjonjon69

Thank you for the awesome/informative post Mort! I know what i'll be getting myself for Christmas...

ToXicXxX

Yup, pulleys are gone, or accessory belts are worn out and stretched, so they are slipping under load.

itzjonjon69

Toxic if you were in my shoes what would you do first and if the pulleys are bad would you buy OEM or weistic billet ones?

ToXicXxX

What millage is on the current belts? Inspect them for wear (cracks/discoloration). If they are worn out, they simply need replacing. If that does not fix it (and this would be my first course of action, because belts are cheap), I would investigate the pulleys. They may just require lubrication, because if they were completely toast they would seize.

AwdthisC63

Agree with the plastic idler pulleys. I have weistec billet idlers on mine for this reason. They tend to seize up and belt rubs plastic pulley or pulleys completely off. Belt tensioner also could cause this to happen as well. I have seen a # of alternator noise with our vehicles (whine noise though). As per power steering noise check power steering fluid level 1st. Control heads and side seals on rack like to leak as well as one power steering line. Usually pump only goes if you run it low or no fluid.

Johnny912

Anyone know what the two front pullies are? Both a bearing inside what seems to be a plastic pulley? Cause they both failed on me today and shredded my belt or at least where I can buy them other than the dealer****

AwdthisC63

Just buy the billet idlers pulleys from weistec. If not you will more than likely has same problem down the road. Early models use 5 plastic idlers late models use 6. Weistec pulleys replace all plastic pulleys so now every pulkey is metal. Just need to purchase a belt. Also remove the electric fan before install of pulleys. Very easy to do and make a lot easier.

itzjonjon69

Thanks for the advice guys look like i'll be picking up a set of weistec billet pulleys for christmas!

edwin07

Did u resolve this issue, i also get this problem when the car is totally warmed and over 1000 RPM. and same to you, the noise didn't come out when you first start up the car.

thaewogrei

They tend to seize up and belt rubs plastic pulley or pulleys completely off.

itzjonjon69

I ended up getting rid of the C63, so i never got to actually fix the problem.

solekeeper

lol, well that was one way to fix the issue.

edwin07

exactly