1996 960 Front Engine Squeal (at Start Up)

kenneth_moorhead · Post by **kenneth_moorhead** » 02 Sep 2006, 16:22

Hello;

I am looking for some help with my wife's Volvo. It is a 1996 960 sedan with about 120,000 miles on it. It has had every major (and most minor) services done and runs really well for a 100,000+ motor.

However, it has developed a squeal at start-up. A very loud one!

Here what I know so far:

* This only happens at start up and lasts for about 10 minutes.

* It doesn't matter what gear your are in, or if you are moving at all.

* It starts out loud and slowly fades away. It will eventually go away completely once the car is good and warm.

* It is NOT the air pump. I unplugged it for a day or so. No dice there.

* It is NOT anything having to do with the drive belt. Once I noticed the water pump was direct drive I removed the belt and started the car. While the computer lit up the dashboard like a Xmas tree, the engine ran perfectly and the squeal was still there.

* It is (I'm 99% certain) coming from the from the front of the engine. Both my wife and I hear it from the same place. However, it is really hard to peg down exactly where it is coming from.

* To me is sounds strongest on the right side (intake) #1 piston.

* It is very high pitched. It sounds like a dying bearing running at high speed -or- something rubbing against a belt. It is high pitched enough that I would be suprised if the cams/crank were producing this noise. The noise sounds higher pithced than something spinning at +/-800 rpm.

* The pitch stays suprisingly constant if you rev the engine. The volume will increase, but the tone does not.

* Finally, this squeal seems to effect nothing other than my wifes ears

Indeed, the car runs perfectly. That being said, given the noise it is making, something gonna break.

My two cents:

I strongly suspect that the source is under the timing belt cover. However, it being my wife's car she insists on driving it about

So I haven't had a chance to peek yet. However, alldata.com shows two idler pullies and a tensioner of some sort. These are my first suspects. The water pump is a very close second.

That being said I have no real idea what this is, yet...

So... any clues, hints, advice, etc would be very helpful and most appricated. Does anyone have any ideas?

Thanks in advance!

Ken

cosmiclobster · Post by **cosmiclobster** » 05 Sep 2006, 00:12

On the 960 there is a single bolt to remove the timing belt cover. It is located in the center of the cover about 6 inches from the top. Take out that bolt and that will give you visual access to the pulley and tensioner.
Take a good look at the pulley! They have been known go bad.
My engine only has about 15 of the 20 or so ball bearings that it originally came with!
If this pulley goes, your timing belt could slip a tooth and you will destroy your engine!!
Want to see what your engine will look like if the pulley goes??
Take a look at mine! Scroll down to see the pictures.
cosmiclobster.com/car.html

Good luck, but I would do something now while the engine still runs versus waiting until that fateful moment!!

kenneth_moorhead · Post by **kenneth_moorhead** » 05 Sep 2006, 18:17

Thanks for the reply.

Well, I pulled the cover without any trouble and notice both pullies had meatal shavings on them.

While I can't say this is unexpected for a 120,000k motor... all the same, the replacements, and a new belt, are on the way

Thanks again!

Ken

cosmiclobster · Post by **cosmiclobster** » 05 Sep 2006, 18:39

Glad to help!
I cringed when I heard you describe the sounds your engine made.
Did your pulleys have all of their ball bearings in them or (as I suspect) there were more than a few missing??

If you change the belt yourself make CERTAIN that all 3 timing marks line up before you crank the engine!!!!!

P.S. The timing mark on the engine pulley is a very small V cut into the top of the engine side of one tooth. Get a good flashlight if you want any chance of seeing it.

Good luck!

kenneth_moorhead · Post by **kenneth_moorhead** » 05 Sep 2006, 19:04

Thank you! Again!

I just posted a question asking about my alignment marks... as I couldn't clearly see the crank mark.

The engine is still together so I'm not sure if all the bearings are in there, but like I said, metal shavings everywhere, so I suspect not!

Also, the squeal is really really loud without the cover on. Both my wife and I think it's the idler pulley, but neither is in good shape.

Unfortunately (for my wife) I can't get to it until next week, but I'll let you know what happens.