Hi all,

I have a 08 MCS. I just replaced my water pump, but this annoying squeaking/squealing sound won't stop.

The noise only occurs after the car has warmed up a bit after about 2-5 minutes of driving and just gets worse the longer I drive to the point where when I come to a stop it drones on until I stop completely. If I'm coasting between 2-3k RPMs I can still hear it if my foot is light on the accelerator.

It first sounded like a belt squeak, which is what I thought it was at first, so I replaced it. Noise continued. Then I noticed there was a coolant leak coming from the water pump, so I replaced it with one of the newer metal ones as opposed to the plastic housing the old one had. Noise still continues, but at least I don't have a coolant leak anymore.

My guess is that coolant leaked onto a moving part below it (friction wheel?), but it's so hard to tell exactly where the sound is coming from in that area since it's so damn loud.

If anyone has had experience with this, insight would be appreciated

 

1.) Did you remember to release the pull tab that holds the friction wheel?
2.) Make sure the w/p pulley bolts are tight
3.) Replace the w/p pulley (the rubber coating will get worn/hard/brittle/chipped off)
4.) Check the bearing in the friction wheel for smoothness/binding

 

The pull tab is retracted and the pulley bolts are tight. The pulley is a bit worn, might as well replace it as well. The friction wheel is pretty smooth, and my guess is that it's not supposed to be so I'll be ordering another one ASAP. Thanks for the tip.