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Transmission Bump

11K views 14 replies 9 participants last post by  Jettplane 
#1 ·
Hello!

I am new to this forum. My name's Garrett, and I've got a 2005 BMW X5 with the 4.4l v8 in it !! I bought it from a Carmax with 75000 miles on it. I've owned it for a couple months now and have put a couple thousand miles on the car so far. I really, really dig this car, but suspect that something a little odd is going on with the transmission. I'll get quite a "bump" out of it under the right circumstances. Like it's dropping the clutch really hard...

If I am coming to a "rolling-stop" - (like say a stop-sign) and I don't *quite* come to a stop and hit the gas a moderate amount the engine will rev-up a bit and the car gets a big-jolt like the clutch was released very "agressively". It's quite a shock, and I am sure it's not good for anything. I can cause this *not* to happen under this same scenario by applying the "gas" slowly with a slight pause. Too much gas under this situation will make it "bump"

Anyone ever hear of this? Hope I don't need a new trans. :(

I haven't driven an automatic regularly in the last 12 years - I don't think this is normal though. Also - if this helps when coming to a stop sometimes I can also feel a very slight "grabbing and slipping" as the trans is disengaging power from the engine.

Thnaks for your help!
 
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#2 ·
Transmission "Bump"

HI I had this too.

Only when as you say come to a rolling stop.

The tech bit= the car is dropping down into second gear not 1st as I thought. It is to do with the timing of the gear changes.

Most of the time the hard "bumps were if I approached a roundabout slowly and hit the gas hard to make the gap then I would get the "Bump".

Only other time was a soft jolt coming up to the lights.

I had a software update done on the gear box and this almost disapeared. On now Rare occasions I might get the soft lurch at the lights, however this is so soft you have to concentrate to notice it.

by the way mine is a 2004 3.0d X5 sport

:thumbup:
 
#3 ·
I had this problem on a Pontiac once when the fluid was low. The mechanic explained that when you brake the fluid sloshes forward and the pickup tube is exposed to air sucking air into the line until you start forward and the fluid sloshes back. If so this is an easy fix.
 
#4 ·
The "bump" is common to the transmission. Mine was replaced under CPO warranty. Others have had success getting the programming for the trans redone. It has nothing to do with the fluid level, though it can't hurt to check (remember to check at the proper temperature).

xoutpost.com has a ton of threads on this with a lot more detail.
 
#5 ·
The thud feels like someone has rear ended you?
I got told I had to replace the mechatronic in the auto (which was re-co'ed last November).

I tried the reset procedure I found on here somewhere (turn key to position 2, press accelerator & hold for 25 seconds, turn off car, restart) & bingo, it hasn't done it for 3 weeks. (But I'm not confident:tsk:)
 
#6 ·
Yes!!! Feels like some rear-ended you - exactly! You hear the engine spin-up a bit, then whomp! I'll check into that mechatronic reset procedure described. I had found some references (Google) to the software/code-updates that were possible, but wasn't sure if I wanted to take it to a dealership yet and have them squeeze money out of me. Is there a way to get it to tell you what "version" of code you're on?

I did buy the Bentley publishers service manual for the car, so it's got a lot of info to tell me where to look for all of this stuff. It's quite a machine!

I don't mind working on cars myself. I've got about 20 years of working on aircooled vw's under my belt. Obviously not the same as working on an X5, but.....
 
#11 ·
May want to call dealer and confirm.....

That was the letter I have received:

BMW VOLUNTARY EMISSIONS RECALL CAMPAIGN
PROGRAM CONTROL UNITS
CAMPAIGN NUMBER: 10E-A03

Exerpt from the letter: "The software release for the Engine Control Unit (ECU) and Transmission Control Unit (TCU) contained errors. This may result in an onboard diagnostic communication failure with a scan tool during an emission test."
 
#14 ·
I have the same "lurch" problem in my 2006 X5 4.4i. -- bought new. Problem started about 80,000 miles. When starting out slowly as in a crowded parking lot or in my neighborhood, the lurch is very noticeable. Have actually felt as if rearended a few times. Dealer has updated s/w twice. No improvement. He says that it is a characteristic of this transmission. The head mechanic also told me that BMW is very guarded about how to really address this issue other than updating the s/w. That really disappoints me that the manufacturer would be that apathetic toward an owner. While I love driving the car, I'm concerned that a serious problem could occur at the worst time. Cost to replace a tranny would be horrendous.
 
#15 ·
What to do??!!!!

Okay so i believe that my transmissoin is bad but i cant necessarily verify it atm.. It gets stuck in 3rd gear i believe its an automatic with a little over 135k. on the freeway ill be at 4000rpms and be goin 60mph yeah so i dont ever ride on the freeway as of now or in general i dont like to take my car anywhere. when i go past a certain speed i get a sign on my dash that looks like a gear with an ( ! ) ive been told my trannys been going out and i cant really do much to fix it? Any help suggestions or comments would be nice on what i should do im lookin into a 5 speed swap right now. Should i try and change my transmission fluids or what?
Help!!!!!! Yeah.... is my transmission going out or what? Hopefully its just the fluids debating if i should hop on changing it asap like today LMK asap!!! THanks
Oh and its a 1994 325is with 135k just a little over:bawling::dunno::confused::eek::yikes:
 
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