Annoying vibration at 50kmh

[awake 1]

My E39 540i has this annoying vibration through the whole car at 50kmh. I can feel it in the wheel, through my feet and through the seat. Seems to go after I speed up but round town when you're stuck behind a lawful driver I'm shaking my arse off. Anyone else had this? My mechanic can't pinpoint it. Thinks it may be engine mounts or drive shaft or both! I don't want to start replacing expensive parts until I know what the hell it is. Failing an answer here, any recommendations for a talented mechanic with the experience to properly diagnose this problem?

[E30stz 0]

one of your gears could be having a mastie.

[topless 13]

I would first have a very good look at the whole driveshaft from front to back, one of the uv's could have siezed etc.

wouldn't think it would be an engine mount, that would normally only be apparant under hard acceleration, cruising the motor wouldn't be inclined to jump around, especially a v8... if you slip the car into neutral while it is vibrating and the vibration stays, you can normally exclude the mounts. If it stays, bet on the driveshaft.

Edited December 20, 2005 by topless

[*sic 1]

one of your gears could be having a mastie.

i cant seem to imagine this?

i mean when has a gear had any form of phallic equipment?...

and then for it to become rigid enough to apply any form friction to cause this non living object to ejaculate?..

not f**ken likely.

get a woman for gods sake, save your hand..

Edited December 20, 2005 by *sic

[Carl 3]

Did anyone check that you simply need to get your wheels balanced instead of jumping to conclusions?

Engine-g/box mounts cause vibrations at certain rpm points so is not particular to speed, besides, if it is was your drivetrain you'd probably notice the vibrations more under heavy acceleration rather than cruising around at a constant speed.

Get your wheels balanced and if that doesn't fix it it may be that one of your actual tyres is f**ked. I noticed that when switching from cheap barums to good quality dunlops my vibrations all disappeared. Use your spare if you have to pinpoint a rogue tyre.

Edited December 20, 2005 by Carl

[Eagle 1662]

Yeah id check wheel balance first too and maybe rotate the tyres. If that doesnt solve it could be worn control or thrust arms, check the brushings

[awake 1]

Thanks for the ideas, I've had the car in at Marshall Tyres in Newmarket who are supposed to be the best in the business for balancing and alignment but no inprovement. Bugger!

[cainchapman 0]

OK, if Leon can't fix it, it probably isn't tyre related.

Take it over to Dean Jensen at Motorscience and get him to have a look at it.

[conrod 1]

OK, if Leon can't fix it, it probably isn't tyre related.

Take it over to Dean Jensen at Motorscience and get him to have a look at it.

I'll second that, he knows what he is doing. I'll put $1 on it be the centre hanger bearing on the propshaft....

[Neal 545]

Something else to consider , had something similar years back on an E21 Auto , The Flex Discs - Guibo Coupling had failed along with a driveshaft bolt. They are a rubber coupling between the auto transmission and driveshaft. Caused very bad vibration at lower RPM (1,500 - 2,000). I replaced the coupling and the bolt and the vibration stopped. I believe the E39's have these as well and is worth checking this out as it is a less costly option to check first.

Edited December 20, 2005 by Neal

[conrod 1]

Something else to consider , had something similar years back on an E21 Auto , The Flex Discs - Guibo Coupling had failed along with a driveshaft bolt. They are a rubber coupling between the auto transmission and driveshaft. Caused very bad vibration at lower RPM (1,500 - 2,000). I replaced the coupling and the bolt and the vibration stopped. I believe the E39's have these as well and is worth checking this out as it is a less costly option to check first.

And another $1 on that, quite a common problem.

[topless 13]

my money is still on a propshaft problem, your original description of the vibration pointed to this.... uv's, centre bearing, front vibration damper, centering guide, check the lot. Often one of these failing will cause another to fail as well. centering guide is often overlooked.

[awake 1]

Thanks for your thoughts guys, I'm booked in to see Dean @ Motorscience tomorrow. Hold on to your $2. Will keep you posted! :thumb:

[Chris_guy 0]

havent read entire post but do u have standard wheels??

[awake 1]

Wheels are 17" M5 knock offs, but the wheels aren't the problem because the vibration was there when I had 18s on and my mechanic tried the car with standard 16" genuine BM wheels and in every case the vibration remained.

[kerry 10]

hi Geoff,sorry to bother you hope you got your problem fixed ,keven here ,ex mosen euro parts hamilton,im trying to track down Dean Jensen for some infor on a car i am rebuilding.do you have any contact details for Dean,i use  to deal with him a lot through my old business cheers keven mosen