Dingdongler

I know this is a long shot, but I'll give it a go.

The other day I noticed a subtle change in the engine of my car. The engine note sounds a little rougher, this is most evident at really low engine speeds ie less than 15mph. This might just be because at speeds above 15mph the expected increase in engine noise covers up this new/different sound.

Also, I can also feel a little extra vibration through the steering wheel, ie the mechanical manifestation of this noise.
Afaik, there was never really any vibration through the steering wheel, but now there is a little.

Both of these changes are subtle, some people may not have even noticed them, but as I've had the car for a long time its obvious to me something has changed.

Everything else seems fine, and there are no alert messages from the cars on board systems.

The car had a big service from the main dealer about 4 months ago, when oil, plugs, filters, transmission oils etc were all changed.

Its a 4.5 year old BMW M5 (current shape) that up until now has not missed a beat.

Any ideas what it might be?

Thanks

john banks

A few ideas, could be engine/transmission mounts, MAF sensor, VANOS, clutch/flywheel, plugs.

Dingdongler

Plugs changed very recently, and had some sort of Vanos thing changed as part of a 'recall' some years ago.

Thanks for the ideas though, it goes to the stealer next week for a diagnoses, fecking £115+vat per hour labour!

Dingdongler

Looks like you were on the money John!

Just came back from the stealer, they 'reckon' its the Vanos (big issue dating back to the E39 M5)

They gave a printout that showed some previous errors logged with regards to the Vanos, but they are old errors, ie they are reading no error at this present moment.

I can elaborate on exactly what it says if it helps.

Anyway they want £2300 to do it, and then of course there is no guarantee that its definitely the cause of my current problem. They will fix the Vanos, then see if the problem goes away, if it doesn't then they'll look for other causes and bill accordingly!

I really need to make sure its defo a Vanos issue, and then look to find an independant who can do it for cheaper.

Does anybody know if there is a way to make the definitive diagnoses of a Vanos problem?

Thanks

ps just to say the problem is rough engine note and vibration most noticeable at idle and less than 2000 rpm

zip106

It must be worth going to an indy for a second opinion anyway?

john banks

Find a good specialist who can make a proper diagnosis and search the M5 boards I would say. You could post the material you have, but someone that can make a good diagnosis is working on these engines all the time AND is interested in what they do - ie a good independent.

bighead

iTrader: (1)

+ 1...go on M5board for more info !!