Quote:
Originally Posted by Mr.Bimmer
What is the servotronic valve?
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It's a valve by the steering rack that changes steering assist on cars equipped with the tech package. No specifics are mentioned on the BMW tech documents I read, but it must have an electric motor activated by the DCM, based on inputs like vehicle speed, etc.
Seems like your power steering system is working fine, so I suspect your troubles (if any -keep reading
) are related to that valve. Dealer can check for codes, but most likely it's software related IMO, due to the intermittent nature of your problem. I've seen all kinds of electronic gremlins reported on this car, and most are erased by downloading the software again (and hopefully with a newer version).
Having said that, your circumstances seem unique, so it could be that the DCM is momentarily 'confused' by how much assist to dial in. I got the impression that valve is working all the time, regardless of mode, so even if you don't have 'servotronic' activated thru the 'M' button, it still provides variable assist in normal mode, which is simply more than on 'servotronic'. I suggest you drive another M3 before letting a dealer mess with your car, since they're not that familiar with M3's idiosyncrasies like owners are. You don't want them messing with a change of pump that requires removing the rack, etc. just to find out it's behaving the same way
.
I'd start a thread in the regional forums to see if a nice forum member wants to help you out. Since it doesn't involve abusing the car in any way, somebody should be willing to help you. And even if nobody does, I honestly wouldn't bother with a dealer until it gets worse, so you're sure it's a problem, and not just a trait, like the clunking 6MT tranny, clutch noise with clutch engaged in N, etc. Good luck man.