This has been driving me nuts and I can't work it out, so I'm here for inspiration!

 

I have a buzzing / vibration noise at speeds in excess of 80MPH (on a track, of course...). It's an even and consistent noise, it doesn't change in pitch or tone, it doesn't change with speed (it starts at over 80MPH but the noise and volume is identical at speeds above and around that) and it doesn't change if the road surface changes.

 

Tyre wear is even, no signs of anything odd or excessive.

I've flicked all wipers on to see if they were the cause; they aren't.

I can't see anything that could be 'flapping' around on the car, nothing is hanging down below.

There is no sign of anything loose in and around the grills or engine bay.

 

Most oddly, it doesn't happen all the time. Same road (ahem, track...), same weather, same speeds and sometimes I can go days without hearing anything. Other times it happens instantly and every time I hit the right speeds.

 

Also odd, is it can come and go in short bursts. It can buzz for a few seconds, then briefly stop and start again. Sometimes it's intermittent; exactly the same noise, just like it's being turned on and off.

 

It's hard to describe the actual noise accurately, the best I can think of is this... imagine a wheel and tyre spinning at speed and you place a playing card or bit of thin plastic on it just enough to make it 'buzz'. It's that sort of noise.  

 

What on earth could be causing it?

 

Thanks

Mine does the same (at legal speeds) - and after 8 months I've given up trying to fix it.

DMF sending vibrations through the car perhaps ?

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Sorry for the slow reply guys, I thought I'd set this to alert me via email!

 

Gav... would I be right in saying the noise would alter in pitch or tone with speed and gear, if it was the DMF?

 

Fr0d, slightly reassuring that I'm not alone, but annoying to hear you've not fixed it.

Rob

It's a bit like reaching a sweet spot say 2.5k rpm and the resonance kicks in. For me it was behind the glovebox I thought. Mine got a lot better with a SMF. I also noticed the engine cover rattled like mad. Maybe drive with it removed although I never tried it.

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Cheers. The bizarre thing about my noise is it kicks in over a certain speed and sounds exactly the same between that speed and higher speeds, no change at all in any way and doesn't change with revs. It also remains the same if I knock it into neutral and coast for a bit, only stopping when I drop below the magic speed.

 

I'll remove the engine cover and give that a go, so thanks for that tip. 

Having reread this. How about wind noise through the rear door quarters. You need to be a passenger or sit at the back to test this. There is a fix for this using silicone or a hammer. To test someone taped up the rubbers.

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Don't rule out tyres. Maybe swap them front to back for a trial.

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My engine covered rattled like mad. So much so I could hear it in the cabin when idling and driving. Its made of two parts that are just clipped together.

I had to partially remove the foam to get to some of the clips.

Once separated the two parts, I applied some black squirty heavy duty glue stuff (forget what its called) to the two parts and now they are permenamtly joined as one. Superglued the foam back and voila... No more rattle.

Edited 19 July, 201411 yr by abys

My front tyres aren't far off being replaced so that has been on my mind. They're Pirelli too so I have a natural dislike for them regardless.

Rear window noise is interesting, I'll have to pop the Mrs in the back next time we go out!

Thank you all very much