[jessejester117]

My 900 has developed a high pitch squeal coming from the engine bay that is more pronounced at times, and silent other times. I replaced all the belts, and checked the pulley wheels while I was in there, and they didn't seem to be going bad or anything, but this all made no difference to the sound.

It occurs briefly when accelerating very hard and turning sharply, but is most pronounced when braking at low speeds, and continues to squeal even after the car is stopped. It will go away shortly after releasing the brake, and definitely after giving the car a little gas. It will even squeal while simply sitting still, and pushing the brake pedal in.

I've looked around in the engine compartment with a friend pushing the brake, but can't tell for the life of me where the squeal is coming from, as its so high pitched. I'm at a loss, any ideas?

 

[Rodentmaster]

99.9% likelihood of the crank shaft pulley being the source of the noise.
You would be wise to change the oil pump O ring and crank pulley seal at the same time.

 

[turbocon86]

Also referred to as harmonic balancer if you're sourcing parts. The outer pulley is bonded to the inner driver with urethane rubber. The outer pulley separates from the rubber which is what causes the squealing.

 

[crwchf01]

If you can, easy way to check is to place a chalk line across the inner and outer pulley and see if the line shifts, after you have cleaned any thing grimy off of the pulley face. If the pulley shows no sign of shifting and the noise continues, I might look at replacing the alternator mount bushing and the adjustment rod bushings for the alternator. When worn they can cause one of the belts to be looser than the other and possibly cause a squeal. If you have AC installed I would listen around the idler pulley and see if it is failing internally.

 

[jessejester117]

Thanks for all the suggestions! I'll go do some tests and get back to you on what the prognosis is

 

[crwchf01]

Any updates? May also want to check for glazing/checking on your belts.

 

[900t]

If you can, easy way to check is to place a chalk line across the inner and outer pulley and see if the line shifts, after you have cleaned any thing grimy off of the pulley face. If the pulley shows no sign of shifting and the noise continues, I might look at replacing the alternator mount bushing and the adjustment rod bushings for the alternator. When worn they can cause one of the belts to be looser than the other and possibly cause a squeal. If you have AC installed I would listen around the idler pulley and see if it is failing internally.

When it's bad... just grab the belt with the engine off and see if you can pull it along :lol:

 

[Mr.Blackk]

I have they same thing if you havent figured it out see if your alternator is looose and leaning causing the belt to rub thats whats going on with mine you probably need new bushings. Also does anyone know how many bushings there are? i have to pay in advance to order them and need to know how many to get.

 

[turbocon86]

Two bushings on the mount. You should also get the bushings for the tensioning arm. If you've never done this before, it's more complicated than it seems. The bolt that holds the alternator on the mount will not come out with the mount in it's position on the car. You have to remove two of the three mounting bolts (8mm internal hex IIRC) and loosen the center one and rotate the mount to get the bolt to clear the firewall. Sounds easy enough, but the mounting bolts are a ***** to get at. It's been a while since I've done one in-car, so I can't recall what combination of ratchet extensions I had to use to get them loose.

 

[crwchf01]

If you have AC installed, removal of the Alternator will require moving the AC compressor. If stock (untouched by people who lose fasteners) there will be two 6mm Allen bolts holding the compressor to the head. If your AC belt is still installed you will have to loosen it enough to get off of the pulley. Since yours is a later model, there will be a 12mm head bolt where the AC compressor and the upper bracket for the alternator meet. to remove the compressor you will only have to loosen the bolt as there is a slot in the AC bracket. Without disconnecting the hoses to the AC, and moving the compressor so as to not kink the hoses, I have found a piece of stiff foam to allow the compressor to rest against the windshield, and out of my way. The forward and bottom bolts to the alternator are 6mm Allens. You may find it easier to remove your cooling hoses for better access, and if you haven't changed coolant in the last 2-3 years it's a great opportunity. IIRC, a 13mm socket will get the pivot bolt on the adjuster arm out. Also realize if you want to change the belts, the power steering belt will have to be removed first. Sorry for the tome, but have done several recently. Please be sure the washers on the adjustment arm are there or they will make a change useless. will have one on each side of the outer edge of the bushings.

 

[jessejester117]

So I finally got around to digging into this issue; been super busy with work and whatnot. And since my last post the squeaking had just gotten worse and worse. Not sure if that's because it's getting colder too, but whatever.
Anyways, you guys were right. The crankshaft pulley [or harmonic balancer w/e] was completely hosed. It's a wonder I had any power at all.. You can turn the d**m thing with your hand haha. I thought you guys might get a kick out of the video of it: http://youtu.be/lUP8fFDbPds


So I replaced that and the alternator bushings; she purrs now. Hopefully don't have to get in there again anytime soon. Thanks a ton for your help guys