First let me introduce myself. My name is JT and I just purchased a 2006 M5 with 133k miles. I have been wanting one for some time and finally pulled the trigger. I read about the "reliability" of the S85 and SMG so I have some idea of what to expect. I love working on cars, so I don't mind doing the repairs, however I am not very excited about spending $1000 for every part... Oh well! It doesn't matter for now, it's not my daily. And looking at the car in the driveway puts a smile on my face, driving it makes me giggle! It's all I need.
I'm coming from the Sprinter source forum, where I find invalubale information and support for my van, and it seems like the community is just as engaged on this forum. I am excited to be part of it.
So here we go, one week of ownership and the first troubles start!
I took the car on a 400 miles trip to put it through its paces and see what would break. The trans is not happy while coasting in 7th gear. I found a very similar issue from another member but unfortunately, there were no suggestions on how to fix it. His thread is here: https://www.m5board.com/vbulletin/e6...hile-gear.html
When I'm driving the car in 7th gear (manual or drive) and I let my foot off the gas, after a few seconds, it will loose RPM almost going in neutral . The RPM will shift up and down 1-2k and eventually the 7th is out. I can only shift up to 6th. The redline is down to 6.5k. The cog wheel shows up. If i keep very minimal pressure on th egas to the point that I can slow down the car while coasting then the issue doesn't happen. It's only with 0 pressure on gas pedal.
I have played with it a few times and pulled code P2711 twice (Unexpected Mechanical Gear Disengagement) and another one another time but don't remember it. It had to do with TCM. If I stop the car, reset the OBD and go again, I'm back to normal. No Service Engine light at any point.
I suspect an SMG pump but I definitely don't know enough about the car/trans to be certain. Do each gear have their own solenoid for the hydraulics? Maybe the 7th could be clogged/worn..?
As far as I know, here is the maintenance done on the car:
THROTTLE ACTUATORS 100K MILES
CLUTCH AND FLYWHEEL 98K MILES
ROD BEARINGS 83K MILES
OIL CHANGE DONE EVERY 5K MILES WITH ONLY MOTUL OR LIQUI-MOLY
TRANSMISSION FLUSH 130K
SPARK PLUGS AND COILPACKS 95K
The flush at 130k might indicate that the previous owner was trying to fix that problem but I didn't know about it before purchasing the car, and the issue didn't come up while test driving.
I don't have ISTA yet, don't really know what it is but I figure I'll probably have to get into it soon!
Any recommendations on where should I start?
Thank you very much for your support.