Mechanics

VOLVO XC70 GRINDING PROBLEM

2008 Volvo XC70 • 55,000 miles

COLD START GRINDING SOUND

When starting my car, there's a horrendous grinding/vibration noise coming from the passenger-side of the engine block. It is most evident in Park and Reverse, though definitely apparent in Drive as well. Goes away after about 5 minutes drive time, and is much worse in the morning when it's cold outside. The "grinding" comes and goes in those first few minutes, often more noticeable when turning the wheel. The grinding almost sounds like "slipping".

As the noise dies down a bit, it comes back for a split second when I go over the speed bumps on our street -- and always on the down side of the bump.

I did notice that the rubber part of the torque rod was cracked and had it replaced. My mechanic suspected that was the problem, replaced it and told me it was fixed, but when I picked it up hours later and started it cold, the noise was still there. To test it, we drove slowly down the alley behind the shop, and while moving, I placed the car in Neutral (no braking) and the sound was still there (coming and going). And of course, after a few minutes, the worst of the sound dissipated.

After the car is warm, I feel like it's still there (though much, much quieter) in Park and Reverse (at a standstill with the brake on), but goes silent in Neutral and Drive (again, with brake).

Unfortunately, by the time the shop can get the car up on the rack, the sound is gone.

So my question is: What can be causing this issue. I guess it makes sense that it could be some kind of mount issue, but why would the sound go away so quickly. Remember, it's completely gone after the car warms up.

Searching the web, I found this video of a Volvo 850 that appears to have a similar sound -- though I will note it is very hard to compare sounds from a YouTube video!

http://www.youtube.com/watch?v=Yw1z8KfNtig

On it, he claims the issue was a faulty bearing in the water pump.

Any thoughts most appreciated!
Avatar
Canyondrive
January 26, 2013.



I suspect the power steering pump from your description. I suggest starting with having the power steering system flushed and add new fluid.

Start there

Roy

ASEMaster6371
Jan 26, 2013.
Check to see if your torque converter bolts/nuts are loose, they will give a sound similar to that until you put it in gear and drive. Also try sparying your belt with water if sound goes away it may be n that area. Normally blet replacement is suggested at 60,000 miles alon gwith tensioner.

Hmac300
Jan 26, 2013.
I'll ask my mechanic to look at these options. And it's not likely to be another mount issue? And what about the bearing in the water pump thought?

Tiny
Canyondrive
Jan 27, 2013.
Normally a water pump bearing wont' grind it knocks, but easy way to check that is to remove blet and start car that way it wold tell you it's in the belt area wher ethe noise is coming form.

Hmac300
Jan 27, 2013.
I only mention this additional clue as I have yet to get to the mechanic: I've noticed that the sound is getting a little worse, but I've also noticed that the sound does exist now when the car is warmed up. BUT I only hear it when I'm cruising along and I take my foot OFF the accelerator.

And I'm starting to think that sound is slightly more rattle and grind.

Is it possible the busted rubber on the torque rod let another mount somewhere get a little loose? Could these clues explain such a situation?

Thanks.

Tiny
Canyondrive
Feb 2, 2013.