X5 Updates and fixes.
 

I have an x5, 3.0 , 2001 auto: 185K miles. Drives very nice and still gets 23mpg at 75 on the highway. After a recent software update and ECU re program they still were not able to increase the idle to 750 rpm. The low idle sometimes less than 500 is the cause of this constant funky vibration. Oh well, it's an old bimmer. So, I want to go ahead and do some fluid updates. Last auto trans fluid and filter change was around 120K. I can't remember what we used for fluid. We drained it completely. I also want to change out the front and rear diff fluids and the transfer case fluids. What are the diff weight rates ? Synthetic? Trans axle fluid weight? I need this x to last a few more years. I was told it is in exceptional well cared condition by a very knowledgeable mechanic in Conyers,Ga. He found the initial front end bounce and vibration to be from:... flat spots in the tires. Three prior mechanics suggested other fixes that didn't fix the problem. Oh well.
thanks J

Diffs take Syn 75-90, TC takes ATF. I went Mobil 1 for diffs and RedLine for TC.

Did them at 100k miles, will do again soon at over 180k.

75w90, synthetic, without LS additives, in the diffs. Redline version works well. Add a squeeze tube of the Liqui Moly antifriction additive. Redline [D4? check their website] or MobilOne syn ATF in the tranny and, I believe, in the 2001 era transfer case. Who was the 'knowledgeable' tech in Conyers? From my years of ATL bimmer experience, I don't recall hearing about a guy out that way ......

G&C Repair
 

The mechanic is Oliver - 25 years from Brooklyn to Atlanta BMW dealerships.
Very skilled and knowledgeable.

Funky thing the other day. Started her up, and the dash lit up like a xmas tree. "S E S", Rear Air suspension, Brake, ABS lights all came on. Checked all fuses. Fine.
So, I hit the brakes hard a couple of times and poof the 'brake", ABS, Suspension" lights go away, SES stays on.
Then again, but this time the rear end locks up, engine goes into a drag/stall and won't accelerate, hit the brakes hard, and poof, it accelerates and drives away. Next time I start it up, happens again. No lock up, hit the brakes hard and poof, lights out, but not the SES. BTW, checked all fluids and idle/acceleration normal. BUT THEN, driving home, same thing at start up. Hit the brakes hard, everything is fine and after 15 minutes the SES light goes off. Cruise back to PC. FL 75/80 flawlessly. No issues. BTW, brake fluid is less than a year old. Front brakes, rotors,calipers changed less than 10 K ago.
Is that not some funky bimmer stuff. I didn't panic because I had the entire vehicle checked out, recent oil change and everything was given a very clean bill of health.