1997 850 GLT whining sound - video

[m491]

I've had some posts about oil consumption and that issues seems to be a quarter every 100 miles. Not great but not the death nail for an 850. But now a new issue has popped up (850's will keep you from getting bored:)

There is a buzzing/whine that is coming from the area of the alternator. It is below the PS pump and I checked the pump by making hard turns with the wheel local to lock and no change in the sound. I have a video attached below. Any ideas of this sound?

[kanona40]

Sounds just like a water pump bearing going bad.

I would get a mechanics stethoscope (Harbor Freight, Sears, etc). They are cheap, less than $10. The sounds in an engine bay can easily travel through other parts like a sub-woofer can produce sound that travels through walls It can help to isolate the sound.

Take the outer timing cover off (I think they are 10mm bolts), and while being careful to avoid the many belts, and If you have never done this before (while engine is running), I would touch the end directly to the cam cover or other easy, no belt part of your engine and hear how loud or soft the sound can be.

Then I would start with a touch to your alternator, and water pump (anything else rotating with bearings if you are still searching). If your water pump is bad it will be very obvious with the stethoscope. That sound will be isolated and amplified.

[m491]

Thanks for the great idea. The stethoscope is a whole $3.99 right now at HF. I have been search for similar issues and saw a video on youtube where the guy thought it was his water pump but it was a bad hose in the PVC system. Mine was done 3 years ago so I don't think it is the issue. I'll have to "lessen" to the various components and see if I can isolate the issue. I'll post back with what I found.

[Clockboy]

Why not take the serpentine belt off and start the engine. If the noise is still there you know it is something under the timing belt cover. If not then it is one of the things that engage with the belt like tensioner, alternator, etc. That will narrow it down for the stethoscope. I had a high pitched squeak that I could not find even with the stethoscope because it only happened in the first 30 seconds of start-up. Ended up being the cog on the waterpump rubbing against the housing.

[abscate]

My experience says to deal with that noise ASAP. Those low frequency components are things that are getting nasty, like metal machining metal somewhere.

High frequency chirps and chips can wait, that noise can't.

Use a piece of hose or plastic tubing (better) to isolate noise.

[m491]

The car is sitting right now. Actually I have replaced the car for my son with a non-Volvo (sorry) and this one when fixed will be up for sale. He's driving for an internship coming up and I needed something that I can safely go to work and not expect a call that starts with "dad, the car is ...." In the mean time I'm learning something new about 850/70's I haven't had happen before.

[rspi]

Why not take the serpentine belt off and start the engine. If the noise is still there you know it is something under the timing belt cover.

This...

[m491]

So I begin to diagnose this issue today (the car has been sitting for since it started). I go to turn over the car and at the first notch of the ignition the noise happens when the car is not started. It's almost like a pre-starting pump or vacuum hose that is making the sound. The sound is definitely coming from below the wiper bottle area in the passenger front fender area. there are no vibrations I can find at the first check but the sound of this is absolutely rattling so the offending part has to be vibrating. I have another video attached below with the the car not running but the key turned one notch right before the starter would kick in. This is a new issue for me. Any help is greatly appreciated.

[m491]

I can't get the video to embed so here is the youtube link.

[m491]