Since my 2010 clubman was new, it's made a buzzy rattle between 2700-2800 RPM. Yesterday I set the cruise control to maintain this rpm in 3rd and found it. The footwell panel adjacent to the accelerator near the firewall rattles against what I presume is the heat exchanger. I found this out the hard way when I felt behind there when the car was hot and burned my fingertips. But a chunk of folded cardboard back there took away this mysterious rattle!

Chloe is MUCH quieter now.

 

Firstly, well done in isolating the problem; but I don't know if it's such a good idea to wedge some cardboard into a confined area that radiates a heat level high enough to burn your fingers...

I'd look for a more heat-resistant material to put there if you're going to stick with your DIY solution... You might also check to see if some retaining bolt on one of the components in question has worked itself loose.

 

I should have mentioned that the cardboard is not in direct contact with the hot components,rather it is between two plastic parts, but I'm just happy to have solved this annoying issue! I will be working up a more permanent solution now that it's isolated.
The interesting thing is, the noise always seemed to be coming from the left corner of the dash; very curious how sounds transfer and echo through a vehicle. It must have been be telegraphing through the firewall.

 

Very good! Just didn't want you to inadvertently create a larger issue for yourself!

Yeah, annoying sounds like these are notoriously hard to isolate. Again, well done!

 

I had the same buzz at the same RPM and just did the same thing and it's gone! Thanks for pointing me in the right direction!

 

BTW, cardboard has a pretty high ignition point, it would have to be VERY hot to ignite or smolder it.

 

Thanks to this fix I'm down to just one buzz in the rear seat somewhere. It only happens when the outside temp is about 85 which is just about every afternoon here in Hawaii. This car feels amazing when all the rattles and buzzes are gone!