Hello all,

I've got a strange problem on my 2004 US spec C2 manual.... On the way home from work tonight, I started hearing a really strange metal grinding noise. It has a loud, constant hum at idle, and as the engine revs higher it starts to sound really loud - similar to the sound of a subway train grinding on the rails around a tight turn. The engine runs and drives fine, and the noise varies with engine RPM regardless of whether the car is in gear or not.

I've never heard anything like it - I really have no clue what it could be. My only idea is that the belts were replaced 4-5 months ago and made some very light squeaking afterwards...? Other than that, there we no warning signs leading up to today. Car has always run well and quietly!

Any insight would be HUGELY appreciated, as I don't have a reliable mechanic yet in this city yet!

Video of noise:

 

sounds like one of the pulleys or water pump.

 

My bet is one of the idler pullies. Take the belt off and run for short bit to check if sound gone.

Waaaahh.....?

 

I see a fray piece flying around with the belt rotation. The belt is worn. If the belt is old then the elasticity will have deteriorated causing the belt to be harder especially if the car has not been run regularly as it should be. I would change the belt then check pulleys for any wobble or noise. Pulleys can be changed if needed. All easy DIY work. Take a photo of the belt before removing so it goes back the same way. I think the belt on mine might be due for a change. Last change was 30,000 miles back. You say the belt was change recently so it has to be a wobbling pulley.

 

Interesting feedback, as the pulleys and belt were allegedly changed 4-5 months ago..... car is at a mechanic who will look at it on Monday. Will report back with what they find....

Thanks for the info!