shifting problem? - BMW Forum

Thejoyofdriving · 04-13-2007, 09:02 PM

recently i have bought a 2003 325ci (steptronic tranny), and it seems that sometimes when i shift from 3 to 2 the car jolts, it feels like something is catching, but i have no idea. what could it be, and should i take it to a dealer?

Hootie · 04-17-2007, 07:50 AM

Cars usually do jolt when you down-shift, especially in the lower gears. Do you get this jolt when shifting while continuously pressing the gas pedal?

Thejoyofdriving · 04-17-2007, 10:17 PM

well i am familiar with the sudden jolt from shifting down to slow down(shifting down while foot is on the brake) or or to down shift to gain rpm and accelerate faster(shifting down while foot is to the floor), but this is different, it feels like something is wrong, like something is catching or not working properly. almost like there is a small pebble in the tranny, and it just gets caught in between the gears, this is probab,y not the cause but im just saying thats what it feels like.

Hootie · 04-19-2007, 07:49 AM

The car's not quite a full 4 years old... have you changed the tranny fluid? Your description of a "pebble" being stuck in the tranny would be similar to solidified gunk coming loose and being lodged in a crevise, something that users here have commented can happen if you change old tranny fluid on the steptronics.

Thejoyofdriving · 04-20-2007, 02:14 PM

no, i havent changed my fluid, but i was thinking of flushing the tranny and doing a lube change. And it only happens when i switch from 3 to 2, if a piece of gunk gets loose, wouldn't it get crushed?

abelinkoln · 04-23-2007, 01:10 PM

Quote:

Originally Posted by Thejoyofdriving

no, i havent changed my fluid, but i was thinking of flushing the tranny and doing a lube change. And it only happens when i switch from 3 to 2, if a piece of gunk gets loose, wouldn't it get crushed?

First off, you may still have a factory warranty on it, so why not take it in? BMW warranties transfer to 2nd owners usually.

Secondly, a steptronic (especially an 03), should never jolt. I wouldn't mess around, and I'd get it in ASAP. Stay out of manual mode on it and no downshifting until you get it in, because any kind of unusual jolting could be causing some kind of further damage.

Not to be doom and gloom here, but I'd rather see you take it in right away for a diagnosis (especially if you're still under warranty) than have to replace a BMW transmission (not cheap!). When transmissions talk to you, you should definitely listen.

Hootie · 04-24-2007, 08:44 AM

"if a piece of gunk gets loose, wouldn't it get crushed?"

I'm not an expert by any means on Trannies, but I believe BMW auto trannies use gears as well as hydraulic pieces. If a piece of gunk comes loose, it could become lodged in a hydraulic tube. And abel is right, take it in for a diagnosis. Even if you drop $300 for them to tell you it was a chicken wing in your filter pan, it's less than the cost of replacing the steptronic ($4,000+).