[wrrush]

so this has happened over the last couple months on and off. ill be driving at forty or eighty and the whole care will slightly kick back several times and it feels like the gears are slipping. My odometer does not move, its like a small jolt to the whole care and passengers can feel it.

i thought it was in the engine, some kind of small misfire, so i replaced spark plugs, coil packs, walnut blasting, new air filter, vanos sensors, crank shaft and cam shaft sensors. Still it continues.

I have a 2007 335xi with just a jb4, i have all the bolt ons in my garage but want to fix this first before adding fuel to the fire.

Thank you for any help. Oh this happens with the jb4 installed and uninstalled. nothing registers with jb4 or carly and no check engine light.

[Underground6t9]

Manual or Automatic?

[Wolf 335]

Probably still misfiring with a faulty injector.

[wrrush]

automatic

[wrrush]

i have a suspicion its the transfer case actuator worm gear is slipping on the xi, i hope im wrong bc that does not look fun to replace

i also have 113k miles

[Chris@VargasTurboTech]

It's all guess work... I'd start by doing a log and try to see if you can capture any relevant engine data when it happens. Go from there.

Chris

[wrrush]

i figured as much, i just thought someone else might have had the same problem who is on here

[TemjinX2]

does it do it when you turn the jb4 off?

were you able to get codes?

[wesley610]

Check your trans fluid if you can
I had the same thing happen to me, previous owner did transmission had work done and whoever did it didn't put enough fluid back in
I didn't think enough of it and it killed my transmission

[wesley610]

Mines a 2008 335xi that was an automatic

[wrrush]

happens when the jb4 is on and off, it doesnt throw codes.

i actually have the trans fluid and filter in my garage just waiting to get on a buddys lift

[335e92tx]

+1 on needing to see a log. Include speed, rpm and gear.