Moan / Buzz noise in traffic.

[bill_mill_65]

I've got a '99 210 300TD estate. I notice that after driving around there's a sound like a buzz or moan at 1200 to 1400 rpm. I think it's something resonnating, but haven't been able to trace it. It's not A/C. Seems to be comming from front left wheel arch area.
Any one had a similar experience or some handy hints?
I did remove the wheel arch liner to have a delve for pipes rubbing etc, and did notice the ride levelling plumbing. Where's the pump for that system?
Thanks! Bill.

 

[Smiley]

engine mounting?
The diesels are more prone to going due to the extra weight of the diesel engine.
How many miles has the car done?

 

[bill_mill_65]

OK thanks for that; it's done 120,000 miles. Doesn't do it from cold if that's significant.

 

[Smiley]

less likely to be the engine mounting then - it would not be any different hot or cold.
How about a heat shield on the exhaust?
Does it make the noise when the car is stationary and you rev the engine slightly or only when moving?
It is not a piece of trim in the car vibrating slightly is it - even a sun visor or door pocket can vibrate at certain engine revs or road speed?

 

[spock500]

I had this on a couple of cars, both times it turned out to be the vents when the car warmed the cabin fan would come on and off they would go -

Swift clump with hand every now and then fixed

 

[bill_mill_65]

Thanks guys. I took the lower bumpercover off to have a rummage; look for rubbing pipes etc. The only thing I could see that wasn't correctly fitted was the plastic duct surrounding the oil cooler.
This appears to have fixed the issue! Certainly the 'cooler will vibrate with a frequency that relates to engine speed so maybe that was all it was!