'98 V70 base, FWD, 5 speed. Bearing Scratchy Sound

Post by **E Showell** » 16 Jul 2016, 08:52

Getting what sounds to me like a scratchy bearing sound from inside the engine compartment. A/C went out at about the same time as I noticed the bearing sound. A/C compressor is original to the car (312k miles). Power steering pump is also original to the car. Other possible suspects, alternator (also original to the car), water pump? T-belt tensioner pulley? T-belt idler pulley? The T -belt, water pump, tensioner and idler pullies are all OEM and were replaced at 249k miles within the last four years. I haven't noticed any charging warning light on the dash (or any other warning light for that matter). No CEL and no codes. I may try and capture some video for posting, but my hunch is A/C compressor. Definitely sounds to me like it is in the serpentine belt travel path, but I couldn't pick up exactly where from the old screw driver trick.

Also, I can't afford a T-belt failure right now.

Any thoughts?

Post by **abscate** » 16 Jul 2016, 10:50

Im working on posting the video, but can you try a hose pipe to isolate the PS, AC Alternator perhaps?

Get about three feet from the car and move/have an asst move the pipe near the components. Watch out for that moving belt!

Post by **abscate** » 16 Jul 2016, 10:56

Another way to isolate

Alternator (assuming DRL are off) - cycle bright headlights on/off and listen for noise change

PS - turn wheel half turn left/right while still - listen for noise change

AC - cycle AC button off/on slowly (once every 10 sec, listen for compressor kick in/noise change.

Post by **E Showell** » 16 Jul 2016, 11:00

Good thoughts on troubleshooting. I'll see what I can do. "Hose pipe"?

Post by **abscate** » 16 Jul 2016, 11:14

That thing you pummel witnesses with to get evidence quickly,,,wait, wrong court.

Piece of tubing from hardware store with 8mm opening or so.

Garden hose works ok as long as color matches car.

HAve a good story to tell in case the neighbors see you and call Bellvue. "Im a lawyer' isnt a good defense.

Post by **E Showell** » 16 Jul 2016, 14:03

Listened with piece of 5/8" heater hose to power steering pump (hose pressed to reservoir cap), alternator and a/c compressor. Couldn't tell much difference between any of them. Listened for comparison to other Volvo in the fleet. My hearing is pretty acute and I am pretty musically inclined so I tend to be able to distinguish sounds. I couldn't tell any real difference between any of the components. I also listened while turing off/on high beams (no difference); a/c (no difference) and while operating steering (no difference).

Post by **scot850** » 16 Jul 2016, 16:26

I found it difficult to figure out which item was making the noise as I found the bracket all the parts are mounted to seems to transmit the noise evenly. I ended up replacing the alternator and tensioner (the tensioner was weak anyway) only to find it was the A/C compressor bearings going out.

Next thing to check is any idler/tensioner bearings and then remove the serp belt and see if the noise is still there. If it has gone one of the items on the serp routing is at fault, if it is still there, need to look at the timing belt components urgently!

Neil.

Post by **theWIFES_S70** » 16 Jul 2016, 21:50

Is it like this sound? It happens around 2 mins and 5 seconds. I haven't been able to isolate it... and rationalize why it might be there! I know its timing related... Good luck isolating it and taking care of it. Sounds from that side of the car are so nervewracking.

https://youtu.be/Ti6jXreWhWk?t=2m2s

Post by **E Showell** » 17 Jul 2016, 04:25

That's not it Marco, but thanks for being willing to help.

Post by **theWIFES_S70** » 17 Jul 2016, 18:50

I hope you find out where the sound comes from. Good luck, E.