Odd 'flapping" noise up front

[Peterlech]

My 1995 525i , with 100K miles, has developed an odd "flapping" noise from up front. It sounds like a speedo cable that needs lubrication, but I seriously doubt that this car has a speedo cable.

It only occurs between 60 and 72 mph, and does not vary with the car or engine speed, or wether you are accelerating or decelerating. We looked under the car while on a lift, and could see nothing. I had hoped fo find a plastic bag stuck in the rear of the engine, but no such luck.

Pete
1995 525i

[Scott C]

My 1995 525i , with 100K miles, has developed an odd "flapping" noise from up front. It sounds like a speedo cable that needs lubrication, but I seriously doubt that this car has a speedo cable.

It only occurs between 60 and 72 mph, and does not vary with the car or engine speed, or wether you are accelerating or decelerating. We looked under the car while on a lift, and could see nothing. I had hoped fo find a plastic bag stuck in the rear of the engine, but no such luck.

Pete
1995 525i
Check the black plastic piece under the wipers - may be "flapping", mine was...
Scott

[GoldenEagleFan]

Check your trim around the front glass. I had a similar noise and found that if I tapped the trim around the front glass at the seam at the top it made the sound I was hearing. A little adhesive took care of the problem.

[Peterlech]

Thanks. I never would have looked there. The trim is loose in the center, so I shimmed it a bit to see if that does it.

[632 Regal]

check the engine splash shield under the front of the engine, make sure its bolted with the 4 bolts and not cracked, kinda sounds like its closer lke the trim as posted.

[Peterlech]

Well, FYI finally found the source of the noise when the windshield molding on the right side came loose. it took a speed of 80 mph and a 40 mph headwind to dislosge the molding.

Everyone who heard it swore it came from in front of the dash behind the engine!

The bad news: one of the clips holding the molding at the upper right corner of the windshield fractured, and you have to remove the windshield to change the clip. I was told that my glass will likely break if we try to do that, due to 2 stone "Star" chips.

Guess I will try some silicone adhesive after I bend the molding back into shape again.

[632 Regal]

dont know about the clips. dont use silicone as an adheasive as it traps water and causes quick severe rust. Use something like urethane rubber which they use for mounting windshields. should be able to get a tube at any hardware store or glass place.

[Peterlech]

dont know about the clips. dont use silicone as an adheasive as it traps water and causes quick severe rust. Use something like urethane rubber which they use for mounting windshields. should be able to get a tube at any hardware store or glass place.

OK. What is the difference between Urethane rubber and silicone? Aren't they both waterproofing sealants?

[pingu]

I also can't see any reason not to use silicone - I've successfully used silicone in the past to install a car rear windscreen. No rust. Urethane would also be quite capable of trapping water.

A bonus of silicone is that it bonds well to the hydroxyl surface chemistry that you usually find on glass. A downside of silicone is that it is attacked by UV - hence the black strips bonded onto the inside of the windscreen to protect the "glue" that holds it to the chassis. I suspect that urethane is also liable to be attacked by UV so might as well get black coloured stuff.

I think urethane tends to be cheaper than silicone and doesn't produce acetic acid when it cures - this might be a reason to use urethane in preference to silicone, though for all I know urethane might produce something worse when it cures!