Unknown intermittent scraping or grinding sound

V_ROWDEN

MEMBER
BMW 740

I'm new to BMWs, 3 months ago I bought a 1998 BMW 740iL with 146,000 miles with a 4.4 liter V8. It has most all bells/whistles, auto trans with Sport driving modes, dynamic suspension control, etc.
The problem:
It just started making an intermittent grinding noise when the car is under a light load (constant & steady spead in "D"), and the noise will stop when I take my foot off the gas, or if I accelerate. I can't tell for sure where noise is coming from, but wierdly enough, it sounds like it's coming from under the front hood - towards the passenger side somewhere. I dont thinks it's a wheel bearing because it stops grinding immediately when I take foot off gas. Not sure it's the transmission becuase it sounds like it's coming from the front somewhere? It doesnt do it all the time, but seems to be getting more frequent.
I dont know what it is, but it sounds bad, grinding-like. Can anyone help me with this? Maybe it's something specific to a BMW 740, OR, I dont know. Please help if you have any ideas. I dont want to go a car dealer/repair shop with no ideas what's wrong.

3 Replies

DOCHAGERTY

MECHANIC
9,601 POSTS

I would say you need to get the car on a lift and inspect the exhaust system. It sounds like something is touching somewhere

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Sunday, July 22nd, 2007 AT 4:22 AM

TBACHTA

MEMBER
1 POST

V_rowden - did you ever get this figured out? I have the same model car w/ 102000 miles and this started happening. I know it has been a few years since your post but this is the closest that I have come to someone having the same issue.

Thanks