X3 M40i Hesitation Issue
X3 M40i Hesitation Issue
Author
Discussion

Coley88

Original Poster:

2,965 posts

221 months

Monday 9th November 2020
quotequote all
We’ve got an issue with our X3 M40i

It has hesitation under very very light acceleration, it`s most noticeable under load, going up a gradual hill and at circa 20mph to 30mph (after that the road noise tents to drown it out), though you can feel the sensation.

It’s been into BMW twice under warranty. They admitted that there was an issue, changed the transfer box oil, it didn’t fix it. Then changed the transfer box.

The issue is still present. The master tech went out in it today and they’re now saying “we can’t replicate the issue”. Basically a cop out as in my opinion they can’t find out what it is.

It is quite disconcerting, we`ve had numerous people has passengers (who are not remotely car people) saying; what is wrong with this car.

The temptation when road testing is to put your foot down, but when doing so, it`s not so noticeable, hence why I`m guess it was signed off as fixed previously.

I`ve done some reading up online, though as ours is a fairly early model, there`s not a huge amount out there. That said, pretty much all issues seem to point back to transfer box, which has been changed.

Any ideas would be welcomed.

pills

1,822 posts

267 months

Tuesday 10th November 2020
quotequote all
Disclaimer - I'm not a mechanic but I wonder if this is a gearbox issue with the hesitation been caused by the gearbox "hunting" for the best gear?
Would it be worth discussing a re-flash of the gearbox software with BMW?

g3org3y

22,504 posts

221 months

Tuesday 10th November 2020
quotequote all
Staggered tyre set up? Star marked tyres? How's the wear front vs back?

OtherBusiness

889 posts

172 months

Tuesday 10th November 2020
quotequote all
Might be worth doing the adaptive gearbox reset?

Turn on the ignition. If your BMW has Start/Stop button, press the Start button but DO NOT press the brake pedal.
All the dash lights will turn on. ENGINE SHOULD BE OFF.
Now, press the gas pedal to the floor and keep it pressed. (Ensure the kick-down switch is pressed )
Keep the gas pedal pressed for 30 seconds. (During this procedure engine should be off, ignition still on.)
Release the gas pedal.
Start BMW and drive normally.

https://www.youcanic.com/guide/bmw-transmission-pr...

DiamondLights

334 posts

76 months

Wednesday 18th November 2020
quotequote all
what year in the car?

and does it happen in both Manual and Auto variations across Comfort/Sport etc?

Deano_BMW

430 posts

216 months

Wednesday 18th November 2020
quotequote all
I appreciate it isn't the same car but my brothers F30 X-drive had really bad hesitation/jerkiness problems. it was in and out of various garages/dealers while he had the issue investigated. He also had the same diagnosis as yourself and ended up with a new transfer box under warranty-that also didn't cure his issue.

His did end up being a tyre issue. he drove the thing like he stole it most of the time, and was working the rear tyres much harder than the front (even though that kind of goes against the x drive philosophy sort of) so they were wearing down much quicker than the front. That was enough to confuse everything apparently.


mekondelta

721 posts

290 months

Wednesday 18th November 2020
quotequote all
Front and back tyres must be within 3mm of each other. Symptoms match the ones I had (F25 X3) and sorting the tyres fixed it. Ensure star marked tyres too.

Coley88

Original Poster:

2,965 posts

221 months

Saturday 21st November 2020
quotequote all
After a very frustrating initial response of “can’t replicate the issue” come and collect your car.

I’m pleased to say that the issue is fixed.

The two Vanos actuators were replaced. £1,700 each. Thankfully under warranty.

It was raised through something called PUMA a system BMW operates whereby it shares data between dealers on a global basis for helping resolving issues with faults.

gizlaroc

17,251 posts

254 months

Saturday 21st November 2020
quotequote all
Missed this.

Reading the first post I was going to say BMW have had lots of issues with failing EGRs giving the same issue on the B range of diesel engines, so my guess would have been Vanos actuators or similar on that engine.

That feeling like the engine is starved of fuel for a split second when you start to accelerate is a proper tell tale sign.

Glad they got it sorted.