jerking during acceleration

[ngary]

Hi just purchased 2006 e83 2.0 manual diesel....
Had to get rid of my 02 x5 ....head turbo gone....220k miles..

The x3 has 80kon clock....first proper.run in it today and finding that between
2 to 3 k rpm there is a physical jolt.....and engine management light has come on.

There is no smoke and.gear changes are smooth...

I know codes will need to be read but wondering if any suggestions as to likely cause....turbo, injectors etc.....

Cheers

Gary

[jdd]

Although I don’t have the same car as you I had exactly the same symptoms as you describe and hunted everywhere to find an answer. In the end it wasn’t until the problem developed a little further that I finally realised (with the help of a scanner) what the problem actually was.
Now, this may not necessarily translate into the same problem for your vehicle but I understand the E83 and E53 share the same components in this area.
What was causing my jerkiness was the fact that the transfer case clutch was slipping, which was caused by a worn gear on the XDrive servo motor.
BMW only sells the complete servo motor, but you can replace just the gear inside for a fraction of the cost and it’s a fairly simple job.
Hopefully, this is the same issue with your vehicle and that you can also get it rectified quickly and cheaply.
From what I’ve read, this is a reasonably common problem and none of the various symptoms people have written about with this fault were similar to what I experienced.

[ngary]

Hi

I connected to the ODBC port - the error coming up is
4203 Glow control unit...

Would this cause the hesitation / jerkiness during acceleration ??

Cheers

G

[jdd]

I highly doubt it, glow plugs and associated control unit only affect the starting.
When my problem originally started it did not have any fault codes and was not until a warning (actually 2 - DSC inactive and 4x4 inactive) came up on the dash with the 4x4, ABS & brake lights on that a code could be extracted.
I would think if there was something else wrong (eg a bad sensor), you should have an error code that can be read.

[ngary]

Hi

Car is still jerking when accelerating and clunking.

Garage is saying that the transfer box is ok, but suggests that the staggered tyres size is the problem. I have checked my VIN, it inidciates staggered size 18 tyres are correct for the X3.

The tyres however are not BMW star rated.

I have the following error codes 5DEA and 5F1E...

Is the garage trying to fob me off, or can non star rated tyres really cause such a major problem.... is there a diagnostic process than could establish if transfer box is the main issue ????? Is it likely to be the chian in th transfer box that is worn and needs replacing ??

Cheers

gary

[ngary]

Well the garage changed the front tyres only and the difference is remarkably better.

I can still feel some judder, in 3rd gear and above when under load.....but much improved.

G