Home Forums Articles How To's FAQ Register
Go Back   Xoutpost.com > BMW SAV Forums > X5 (E53) Forum
Fluid Motor Union
User Name
Member List Premier Membership Search Today's Posts Mark Forums Read

Xoutpost server transfer and maintenance is occurring....
Xoutpost is currently undergoing a planned server migration.... stay tuned for new developments.... sincerely, the management

LinkBack Thread Tools Display Modes
Old 03-20-2013, 01:28 PM
Join Date: Feb 2013
Location: WPB, FL
Posts: 19
knfxda is on a distinguished road
Thoughts on a Transmission Issu

I have a 2001 4.4i and for some reason, I decided to top off with 89 Octane (10 gallons), today. I normally run 93 Octane, but wanted to see if a "blend" of the 2 would be noticiable.

The engine runs fine, however within 10 minutes of doing so, the transmission is now shifting late. I never run it in Sport mode, but it feels to me like it is stuck in Sport Mode. Shifts are not occurring until about 4k rpms. Downshifts are also late to the game.

I tried Sport mode and there was no noticeable difference or improvement. I tried manual mode and it still appeared that the "software" was overridding my choices. I would shift into 4th, but it would not shift and then indicate 3rd.

I've only driven about 15 minutes like this and given the roads that I was on I was not able to push it beyond 4100 rpms in 3rd to see when/if it would shift into 4th.

I've had no problems otherwise with the trans. It does have 115k miles on it and I have not changed the trans fluid (nor did the prior owner, I suspect - given the state of all of the other fluids that I have changed).\

Honestly, even with the high miles, the trans was one of the factors that I used in buying the X as it was so smooth and appeared to have no issues.

Could 10 gallons of 89 octane really affect sensors to the point that the trans is acting this way?

Open to any thoughts or suggestions.


Reply With Quote

Sponsored Links

Old 03-20-2013, 01:37 PM
upallnight's Avatar
Join Date: Aug 2012
Location: Cook County
Posts: 7,280
upallnight is on a distinguished road
Well with lower octane gas the knock sensor will tell the computer to retard the timing so that the engine won't self destruct. So yeah, lower octane can affect the way the trans is behaving. Next time put back premium and see if the problem don't go away.
2006 Infiniti G35
2001 BMW 3.0I E53 X5 Build date 08/2000 SOLD
Lotus Europa 1970 Destroyed by fire
Lotus Europa 1970 S2 Renault Powered
Lotus Type 52 1970 Twincam Webers Powered
PORSCHE 911 Targa 1982 The Garage Queen
Audi Avant donated to Kars for Kids
BMW 525IT Sold
Audi 4000CS Quattro Sold
Jensen Healey Lotus Powered Sold
Opel 1900 Sold
Triumph Spitfire 1971 Sold
Triumph Spitfire 1968 Sold
Plymouth "Cuda" 340 Six pack SOLD
Reply With Quote
Old 03-20-2013, 02:45 PM
epdarks's Avatar
Join Date: Jul 2012
Location: Mpls, MN
Posts: 883
epdarks is on a distinguished road
I personally would think the 2 issues are unrelated.

Either way, you are on borrowed time at 115k miles. A trans replacement is likely in your future.
2002 X5 4.6is - Titanium Silver / Black Alcantara - Dinan Stage 2 - Bilstein/Eibach - Brembo BBK ----SOLD---
1993 318i - Brilliantrot / Tan - bone stock daily driver
Reply With Quote
Old 03-20-2013, 03:23 PM
JCL's Avatar
JCL JCL is offline
Premier Member
Join Date: Mar 2005
Location: Vancouver, Canada
Posts: 11,853
JCL will become famous soon enoughJCL will become famous soon enough
Originally Posted by knfxda View Post
Could 10 gallons of 89 octane really affect sensors to the point that the trans is acting this way?
No, not from the resultant 91 AKI octane rating (half 93, half 89).

But if that fuel contained water or too much ethanol, then that could potentially impact drivability. I would expect more engine symptoms in that case, though.

Given that it is not shifting properly in steptronic mode either, it sounds much more like a transmission issue than anything external.
2007 X3 3.0si, 6 MT, Premium, White

2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver

2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue
Reply With Quote
Old 03-20-2013, 04:25 PM
Join Date: Feb 2013
Location: WPB, FL
Posts: 19
knfxda is on a distinguished road
Fixed.... for now

Well, I applied the infamous BMW fix...

I parked the car and turned it off. When I went back to it later, all was good. As if nothing happened. Transmission felt the same as it did previously.

I may be wrong here, but I get the sense that the BMW "compeuters" will sometimes get "confused" and a simple turn the car off and turn it on again seems to reset everything.

Now my problem is that swapping out the transmission fluid was the last thing on my list and I'm worried about doing it, now.

I plan on doing it in 3 weeks or so. So, if I don't see any other symptoms between now and then, I'm going to go for it.

Here's hoping I don't regret it!

Reply With Quote
Old 03-20-2013, 04:30 PM
Join Date: Feb 2013
Location: WPB, FL
Posts: 19
knfxda is on a distinguished road
I forgot to add - the only other thought that I had was that CPU took somthing I did as "aggressive" and it "learned" that I wanted to drive aggressively.

After shutting down the vehicle, it unlearned this and went back to its normal programming.

That is the only thing that makes sense.

It really didn't feel like a "transmission" problem (in the sense of gears/clutches/moving parts and the like). It felt like a cpu problem. It seemed to be running a different profile than normal. There wasn't any slipping, hard shifts, clunking, etc, or anything that you would normally think of as mechanical problems.
Reply With Quote
Old 03-20-2013, 05:00 PM
Join Date: Jan 2011
Location: Blackburn UK
Posts: 408
RRPhil is on a distinguished road
One possibility : The transmission has a 'cooling strategy' mode which is activated automatically by the ECU if the transmission fluid temperature is unacceptably high. In this mode, upshifts are inhibited to deliberately maintain high engine speeds and therefore oil pump speed (and hence flow through the cooler). If you have a laser IR thermometer it might be worth pointing it at the transmission sump pan next time you get this problem to see how hot the fluid is getting.

On Range Rovers (same engine & transmission) this problem is very common because the bottom eight rows of the main radiator, which provide the cooling water to the transmission oil cooler, become blocked with sediment over time and stifle the cooling flow. I'm not sure whether or not the E53 cooling setup is the same?

Reply With Quote
Old 03-20-2013, 06:52 PM
Join Date: Oct 2011
Location: NYC
Posts: 4,755
SlickGT1 is on a distinguished road
We have just been graced by RRPhil. Awesome.

Phil, have you finished the ZF6 speed rebuild? I have a few valve body questions on the 6hp26 and it delaying reverse engagement for up to 3 seconds, occasionally after a lot of stop and go traffic.
2006 4.8is, Black on White. SOLD Sniff Sniff.

2017 F85 x5m, Black on Red. BEAST MODE

"The older we grow the greater becomes our wonder at how much ignorance one can contain without bursting one's clothes." - Mark Twain

Unlock OBC post 5
Reply With Quote


tranny, transmission, transmission problem

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 03:40 AM.
vBulletin, Copyright 2023, Jelsoft Enterprises Ltd. SEO by vBSEO 3.6.0
2017 Xoutpost.com. All rights reserved. Xoutpost.com is a private enthusiast site not associated with BMW AG.
The BMW name, marks, M stripe logo, and Roundel logo as well as X3, X5 and X6 designations used in the pages of this Web Site are the property of BMW AG.
This web site is not sponsored or affiliated in any way with BMW AG or any of its subsidiaries.