A couple of days ago I went to start up my '96 850 turbo wagon and was greeted with a really rough idle (the motor is vibrating so much that it's shaking the steering wheel and doors) and a somewhat metallic whirring sound (like when you suck up something metal in the vacuum). After checking it out with a buddy we're almost positive that the engine mounts and all of the belts are fine, but perhaps something more complicated (and more expensive) is behind this.

When shifting the car from park, the idle drops back down to normal and the engine revs smoothly. However, when shifting between Park to Reverse to Neutral to Drive, there is a loud shriek and the lights in the car temporarily cut out. Once we shift the car back into Park from Reverse all hell breaks loose and the Volvo lets out a loud shriek and continues to scream until we kill the engine.

When listening to the engine idle when in Park, we think the problem may be coming from inside the engine. Yet, what's confusing us is when we shift it out of Park, the sound stops. Haven't tried driving it with this issue (don't trust the car right now if it is a transmission problem).

Do you guys have any idea what's going on?

Thanks!

 

Sounds like your motor is ready for a party.

Just kidding.

Locate the source of the metallic squeal. Open the hood, and with the shifter in "P", parking brake fully engaged, chock the wheels (don't stand in front of the car), see if you can locate where the noise is actually coming from.

If the engine behaves when the tranny is engaged, I would assume both the engine & tranny are fine but the engine needs an immediate attention before the trouble gets worse. I thought one of the accessories' bearing was seized or the starter solenoid was not releasing, but then it doesn't explain why the car behaves when the tranny is engaged.

Drain the oil and see if you find any metallic particles. If you don't see anything in the oil, your engine is probably fine at this point. Also, disconnect the air hose(s) from the turbocharger and make sure the unit is not seized or any of the hoses doesn't have damage (it is probably fine too, as the engine is revving smoothly while in "D"). I would also visually inspect the timing belt area by removing one 12mm bolt and pulling the cover upward; do this with the engine not running of course.

See attached for idling issue. Also, have a visit to a nearby auto parts shop such as AutoZone and have them pull fault codes from the on-board computer.


JPN

 

My first guess would be that the serpentine belt roller is seizing up. If that's not it, it is possible that another part in that path is. Take the tension off of the belt, remove the belt, and spin all of the parts in that path.

WARNING!!! If none of them seem bad you may have a timing belt idler roller, tensioner roller or water pump locking up. These are harder to check and will require a timing belt removal. I don't think you can see them, but may hear them. If you have a roller in the timing belt area locked up it IS NOT A GOOD IDEA to start the car. If you break that timing belt, you will likely destroy the motor.

 

If it's been over five years or 70K miles since the timing belt was changed, do it now. Most cars don't give you a warning, but yours just might be.

 

Thanks for the advice guys! My mechanic and I are going to take a look at it tomorrow morning, so hopefully we'll get to the bottom of this.

I'll let you guys know what we find!