Thump

[Shergar]

Occassionaly when I start my car (an octy II L&k 2.0 TDi Est) I hear a loud bang which sounds like someone thumping the roof of the car above my head. There is always a sound like a cable moving too between the roof and the lining.

This only happens occassionaly and when it does the radio is switched on tuned to an FM channel. I wonder if it is the ariel cable that I can hear moving between the lining and the roof but have no idea what the loud bang is.

Anyone else had this problem?

[Lowflyer]

Occassionaly when I start my car (an octy II L&k 2.0 TDi Est) I hear a loud bang which sounds like someone thumping the roof of the car above my head. There is always a sound like a cable moving too between the roof and the lining.

This only happens occassionaly and when it does the radio is switched on tuned to an FM channel. I wonder if it is the ariel cable that I can hear moving between the lining and the roof but have no idea what the loud bang is.

Anyone else had this problem?

Yes I've had that loud thump happen a few times on my 1.9Tdi Elegance. The first two times I got out expecting to see a dent in the roof where something had fallen on to it - but ... no evidence of any impact.

I believe the problem is to to do with the audio system - a sudden momentary pulse of bass through the speakers on switch on. I'm not sure what causes it but mine hasn't done it since I had a bad connection to the 6 CD changer fixed.

Not heard the cable moving bit though.

[gadgetman]

Exhaust banging?

If you take a bump fast, does it happen then? If so get the exhaust & mounts checked

[durhamfisher]

This may not be the problem, but my radio used to make a loud bang when starting occasionally, fixed by the dealer with an upgrade? I cannot think of anything that could move in the roof space.

[Shergar]

It's not the exhaust or anything else loose, as it happens when I first start the car in the garage. Lowflyer's description of leaping out expecting to find a dent in the roof is exactly how I felt.

It does sound like a sudden pulse through the speakers. I have checked most of the audio connections, indeed have changed some of them as I have removed the CD auto-changer in favour of a auxilliary input for MP3 and DVD. Before anyone asks, yes it did make the noise before I did that.

Stacon; when you say your problem was fixed by an upgrade, did you mean they changed the head unit or did a software upgrade?

[eddie2]

This happened to me a couple of times when the car was new. First time I thought I must have imagined it, but the second time my daughter heard it too. However it has never done it again since that second time.

[durhamfisher]

The dealer did a recall software upgrade on the head unit last time it was in for a service. Something to do with the radio draining the battery when left for a period of time. However, I havent had the problem since. Can only think it was included in the patch.

[PumpeDuse]

I'd get Rentokil in, sounds like you have rats in your loft.

[DaveI]

It comes through the speakers, happened quite a few times on my Octy, never happened again once they re-flashed my radio on one of the services.

[gadgetman]

It's not the exhaust or anything else loose, as it happens when I first start the car in the garage.

Wifes punto did the same ONLY at start up.

If it happens even when the radio is off, it's worth considering

[Taxi 219]

Turn stereo off and see if it does it.If not at least you know what it is after.