Mystery Scraping Sound

[trm2]

It has happened before, more quietly and intermittently. But today it is embarrassingly, painfully loud. It is hard to tell where it comes from, but I think it is from one (or more) of the wheels. It is a loud, scraping sound (almost grinding but not quite; somewhat high pitched). It seems to start right after an acceleration or wheel turning or braking. And, once it starts, I can sorta stop it by taking my foot off the accelerator and letting the speed go under about 20 mph.

Any ideas? Brake not fully releasing? Problem with a brake pad? Bearings?

I suppose there is an outside shot that it is coming from under the hood, but I'm the only one home and the noise stops when the car does, so I can't check right now.

Thanks.

 

[schafari]

Although you could get lucky and it could be dirt, mud, rocks caught up somewhere and rubbing on something under the right conditions, I would check two other things, the wheel bearings and the belts. Does it only happen when the vehicle is moving, or can you get it to do it while parked and revving the engine a bit? When you move and accelerate and or turn, you may induce belt squeal if you have a foreign substance on the belts.

In today's engines, that is becoming very rare however. If it only happens while in motion, I would try to isolate it to which corner or front/rear of the vehicle. Sounds like it could be a bad bearing as well.

I would spend a bit under the hood and check it out. I would pressure wash the wheels, brakes, underbody and look for evidence of debris. I would check the rotors to see if there is any unusual wear, scoring, or color. (Do this before washing) I would look at the belts to see if anything looks, feels, or smells odd. (Do this whilst the engine off) I would try to get it to make a sound while not moving. If it only does it while moving, I would lift each wheel, and check the bearings.

 

[trm2]

Of course, now I can't make the noise again. I think there was still some noise when stopped (the last time it made the noise). So maybe it is a belt. I think I'll have the dealer look at it.

 

[trm2]

I took the LR3 to the dealer this morning. And I (fortunately or unfortunately) managed to reproduce the sound. While the car was not moving. In park. The repair people kinda came flying out of the building saying "Dear God, what was that?" Metal-on-metal scraping/grinding (but, oddly enough, no poor performance or hesitation accompanies the noise). I'll report back when I found out. Thank heavens still under warranty. I think I'll be getting the extended warranty too.

 

[trm2]

Loose serpentine belt tensioner. All fixed....

 

[nkta]

I have had the same exact issue. Brought to dealer 3x, they all heard it but could not figure out what it was. NOW, I can tell them where to look. Thank you and thanks to the board.