Is this a Transmission problem

[Joe Raif]

Hi fellow bimmers, my friend was asking me about this problem with his E46 318 valvetronic sedan. Its just past 3 years old and he has these problems. Firstly, once in a while when he puts into reverse gear, there is quite a scary jerk from the undercarriage. Sometimes, when he is just about to reverse the car dies just like a manual car when the clutch is released too early.

The second problem is when the car is moving very slowly in a traffic jam, there is a sort of a clunk sound from the undercarriage.

Any of you guys (or gals for the matter) ever experience these symptoms? By the way, he just changed his transmission oil and the mileage is 80,000km. Hope to hear some enlightment from any of you! Thanks.

 

[kurqa]

Re: Is this a Transmission problem

i can only answer 1 of those questions..the engine dies when reversing (slowly?) becasue the idling rpm is set too low. something must have happened to screw the settings..best bring to a workshop and let them fix/reset it.

 

[Joe Raif]

Re: Is this a Transmission problem

Tks. Midling is at 900 rpm now. Anyway, will try and check it out.

 

[VenomX2]

Re: Is this a Transmission problem

for the first issue it could be the air flow sensor?

 

[Joe Raif]

Re: Is this a Transmission problem

Thanks for trying to help Venom. So, is the air flow sensor also causing the jerk from the undercarriage the moment the gear is engaged into reverse?
How do I confirm that the air flow sensor is the culprit and is this going to be a real "ouch" in my pocket to rectify?

 

[esis311]

Re: Is this a Transmission problem

Hi, E-46 model is beyond 3 years old, do you mean F30 model?, I would have the transmission mount, engine mount, rubber bushing as from forward to reverse, the opposite force may create a sound due to loosening of these parts.
But the problem you mentioned could be due to transmission valve control or else, my estimate is to change the transmission oil every 60,000km as due to heat, internal friction(dust), the passgae of the trannsmission is either blocked creating drop in pressure.