BMW Questions? Ask a BMW Repair Expert for Answers.
I suggest you have them do a smooth running control check with bmw diagnostic machine to ensure that fuel flow to all injectors is within limits. Your problem sounds like it could be with the injectors or over fueling. If everything checks out, you should have them do a compression check on all cylinders to ensure compression is correct as well.
Thank you. Your reply gave me more satisfaction than I received from the dealer after 2 days of addressing the problem - 2nd time around!
My fuel consumption is running at +- 7.5/100 which I think is high. I have pointed out that the "consumtion " guage is erratic. It records excessive consumption when idling in traffic - I'm told that is normal. My point is why provide a guage which is erratic?
Could the "jerk" which I experience from the gearbox when coming to a standstill be related to the possible causes which you provided?
Yes that sounds a bit high. I think you might want to get the dealer to preform the test I suggested.
I think your gearbox issue is unrelated (sorry I neglected to touch on this in my first post). What you are experiencing there sounds like a problem with the transmission itself. I would have the fluid level and quality checked. If this is okay, you will need to escalate to a more thurough diagnosis - which should be covered by your warranty.
Let me know if you need anything further. Please press accept if satisfied with my assistance so that I am compensated for my time and effort.
Thank you for your assistance. I will certainly authorise payment.
One more question.
You suggest the possibility of a "more thorough diagnosis" of the transmission problem.
Can you give me a name/description of this diagnosis - I feel I need to be prepared to have the discussion at dealer level
Sure no problem.
The first thing they need to do is put the car on the diagnostic machine and check it for fault codes, etc, and update the software (if any updates are available).
If this doesn't improve the problem, they will probably check the fluid level and quality.
After that, it is going to be their call essentially as to what to do next, depending on the harsh shifting they feel and what they think it feels like. They can monitor the transmissions performance using test equipment, or even opt to tear down the tranny, or, perhaps they will have a good idea of the issue just from the feel of the shift and the overall behavior of the transmission.
There isn't really one set diagnostic procedure. The dealer/mechanic should be able to troubleshoot properly based on the feedback they are getting from the car and the daignostic machine. This should all be covered by warranty and they MUST repair the issue to a level where the transmission is shifting smothly again, as it did when the car was new. If they don't keep complaining until it is fixed properly.
Let me know if you need anything else.