Bad vibrations

[RDBx]

I'm getting a pretty bad vibration through our B6 Passat TDI at roughly 2200 rpm, irrespective of road speed or gear.

Is this likely to be engine related, DMF, mounts etc? Is there any way check these? A visual of the mounts didn't show much apart from perhaps looking a little tired, it has done 115k so expected. Clutch seems fine, no slipping that I can detect.

Vibration is not felt through the steering wheel, so I've discounted wheels, drive shafts and prop (it's a 4motion).

NSL is proving a right pain in 6th, either have to go higher or lower.

I have posed this in the VW forum a couple of days ago but no response, so hope this is ok.

Thanks.

[imagineifyeswill]

Ive had this exact problem at the same engine speed with a Skoda Octavia Scout, the problem it appears is linked to the flexi section in the front exhaust pipe, the cure, put two jubilee clips round the flexi section spaced so that you are dividing it into three equal sections and tighten up, sounds odd but worked for me its apparently not an uncommon fault.

[oakdale]

RDBx said:

I'm getting a pretty bad vibration through our B6 Passat TDI at roughly 2200 rpm, irrespective of road speed or gear.

Is this likely to be engine related, DMF, mounts etc? Is there any way check these? A visual of the mounts didn't show much apart from perhaps looking a little tired, it has done 115k so expected. Clutch seems fine, no slipping that I can detect.

Vibration is not felt through the steering wheel, so I've discounted wheels, drive shafts and prop (it's a 4motion).

NSL is proving a right pain in 6th, either have to go higher or lower.

I have posed this in the VW forum a couple of days ago but no response, so hope this is ok.

Thanks.

Does the vibration alter in any way when you go over bumps in the road or when you are cornering?

[RDBx]

Not 100% sure but it seems unchanged when cornering etc. Will try again tomorrow in a lower gear to check. Will also get it up on ramps to check out the exhaust flexi pipe.

Cheers.

[imagineifyeswill]

you wont actually see anything wrong with the front pipe, its caused by some sort of resonance dynamics that seems to manifest itself at that particular speed which just happens to coincide with NSL, over 2300rpm it dissapears again, I couldnt suss it out on a customers car until I was told by an ex VW mechanic what was causing it and how to cure it, I think it possibly only affects the 4x4s.

Edited by imagineifyeswill on Sunday 25th May 12:08

[RDBx]

Finally managed to get under the car and fit four decent sized jubilee clips round the flexible coupling. Was a bit of sod due to the prop shaft.

And after that, no improvement whatsoever. Have confirmed it looks like the engine mounts are ok though.

Can't think of anything else except for the dmf / clutch now, a dammed sight more expensive than the clips. Bugger.

[imagineifyeswill]

DMF vibrations and noise is ussually worst at idle and can be felt through the clutch pedal by just taking up the freeplay. That is the exact speed that this problem caused by the exhuast flexi occurs at and apparently is quite common, you shouldnt have needed to put 4 clips on, 1 in the centre and if that doesnt help 2 spaced so that it is effectively dividing flexi into 3 equal sections.

Edited by imagineifyeswill on Wednesday 4th June 18:23