Tranny slip/jerk GONE with AC on

petelazro · 04-14-2014, 07:57 AM

Hi guys, so i have been plagued with the infamous tranny slip that does not through any codes. it jerks when shifting up until gear 4 and then its smooth. When coming to a stop it jerks as it downshifts. When i put the AC on this weekend all of the jerkiness went away. Its been 3 days now. I even tried coming to a slowdown and stepping on the gas but it still didn't jerk. When i turned the AC off and tried it again it started jerking again.

On start up i have fluctuation on the rpm about 50-100 up and down for the first 20-30 seconds then its fine. None at stop lights after its started up. checked by 2 dealers, no codes at all. They are stumped as well.

2008 328XI 123K Kilometers on the car.

any ideas? is it a load issue on the engine? I have spark plugs coming in soon. Idk if i am getting a miss fire of some sort. Sparks are original.

been trying to figure this out for a year now. Any help would be great.

akam1 · 04-14-2014, 08:15 AM

from what i figured it was the solenoids/sealing sleeves on the mechatronics unit that needs to be replaced, from getting "stuck" .

petelazro · 04-15-2014, 03:00 PM

but what does the AC being on or off have to do with it? wouldnt that be independent of the AC?

04-14-2014, 07:57 AM	#1
petelazro Second Lieutenant 14 Rep 208 Posts Drives: 2008 328xi Join Date: Apr 2013 Location: Toronto iTrader: (0)	Tranny slip/jerk GONE with AC on Hi guys, so i have been plagued with the infamous tranny slip that does not through any codes. it jerks when shifting up until gear 4 and then its smooth. When coming to a stop it jerks as it downshifts. When i put the AC on this weekend all of the jerkiness went away. Its been 3 days now. I even tried coming to a slowdown and stepping on the gas but it still didn't jerk. When i turned the AC off and tried it again it started jerking again. On start up i have fluctuation on the rpm about 50-100 up and down for the first 20-30 seconds then its fine. None at stop lights after its started up. checked by 2 dealers, no codes at all. They are stumped as well. 2008 328XI 123K Kilometers on the car. any ideas? is it a load issue on the engine? I have spark plugs coming in soon. Idk if i am getting a miss fire of some sort. Sparks are original. been trying to figure this out for a year now. Any help would be great. __________________ 2008 E90 328 X-drive -KW V1- Auto-Sport-Blacklines-LED interior lighting Summer: Style 195 F-225/40/18 R-255/35/18 on Bridgestone RE760 Sport Winter: Style 161 - Sottozero RFT 225/45/17 square
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04-14-2014, 08:15 AM	#2
akam1 New Member 1 Rep 15 Posts Drives: e90 328I Join Date: Mar 2014 Location: Texas iTrader: (0)	from what i figured it was the solenoids/sealing sleeves on the mechatronics unit that needs to be replaced, from getting "stuck" .
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04-15-2014, 03:00 PM	#3
petelazro Second Lieutenant 14 Rep 208 Posts Drives: 2008 328xi Join Date: Apr 2013 Location: Toronto iTrader: (0)	but what does the AC being on or off have to do with it? wouldnt that be independent of the AC? __________________ 2008 E90 328 X-drive -KW V1- Auto-Sport-Blacklines-LED interior lighting Summer: Style 195 F-225/40/18 R-255/35/18 on Bridgestone RE760 Sport Winter: Style 161 - Sottozero RFT 225/45/17 square
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