Help identifying odd noise.

jmana · Post by **jmana** » 03 Dec 2014, 21:53

I need help figuring out what is causing this noise. It goes away after about a minute. It's a 98 V70xc.

Post by **scot850** » 03 Dec 2014, 23:01

Have you tried to listen for the noise with the hood open? It would appear the noise is rev related, but from the drivers seat it is near impossible to pin-point. Does the noise seem to be from the cabin or dashboard area?

Can you update by posting a video with the hood open, moving the camera around the engine bay to give us a better idea of where the noise may be coming from?

Neil.

Post by **rspi** » 04 Dec 2014, 01:37

My guess would be that you have a timing belt roller about to seize. Do you know how old those parts are?

jmana · Post by **jmana** » 04 Dec 2014, 05:31

It actually sounds to me like it's coming from under the car, but I'll check it today from under the hood because I'm probably wrong.

jmana · Post by **jmana** » 04 Dec 2014, 12:23

I checked under the hood, and yes the noise is coming from the belt area (not sure if it's the timing belt or the accessory belt). The car has 190,000 miles and the timing belt was replaced around 100,000 miles, but I didn't own it then and don't know what all they replaced.

Post by **scot850** » 04 Dec 2014, 15:32

Remove the accessory/serpentine belt and start the car. If the noise has gone you know it is on one of the components on that 'circuit' (alternator bearings, idler bearing, tensioner bearing, a/c compressor bearings, power steering pump bearings). It can be hard to easily I.D. the problem component even with belt on and using a stethoscope as all the parts are mounted to an aluminum bracket that transfers most of the noise to other components. Spin the items by hand may give a better idea what is going. Not fixing something on this belt run can also cause major damage. If the belt snaps it can take out the timing belt cover and the timing belt.

If the noise is still there it is something on the timing belt (i.e. fix immediately or it will get expensive) run. Probably one of the idler pulleys or water pump bearings failing. I believe Volvos timing belt change frequency is 80k miles or 7 (?) years (so overdue).

Neil.