Transmission jolt problem ? Gear 1-2 "Is like i get hit from the rear! 03 X5 4.6 is"

[upallnight]

Originally Posted by TerminatorX5

rear right wheel speed sensor... hmmm... why there is no signal? did the dealer address that sensor?

if i remember correctly, right front wheel speed had something to do with gearbox... rear right? don't remember...

Left rear sensor is the speedometer sensor as well so when that sensor go bad you get the trifecta of lights. Ask me how I know.

[TerminatorX5]

you have EGS signal line disturbed, wheel speed sensor, and the gear monitoring...

did you replace both, the brake pad sensor and the speed sensor? how is the status on your software/cable? with INPA you can get plain english (kind of english, mixed with german!!) wording...

your issue could be mechanical and/or electronic in nature...

does your cruise control work?

[bosanci28]

Originally Posted by TerminatorX5

you have EGS signal line disturbed, wheel speed sensor, and the gear monitoring...

did you replace both, the brake pad sensor and the speed sensor? how is the status on your software/cable? with INPA you can get plain english (kind of english, mixed with german!!) wording...

your issue could be mechanical and/or electronic in nature...

does your cruise control work?

"brake pad sensor and the speed sensor" yes, i did replace both with new,i remember when those where ripped off ,i had Christmas lights at dash, but all when away after i did the install on both of those 2 sensors.

regarding the INPA , i am still looking what to get , i was going to get this one here,
but i dont think it comes with the inpa software!?,also must work under windows 7 64bit.

maybe a combo was better to buy cable and software from the same seller,and to be from usa,for faster shipping.

also this guy here selling :
"BMW DIS v5.7 + INPA 5.0.2 + Ediabas v6.47 + SSS v32 + Carsoft + NCS Expert/Dummy"
25$, link

thanks,

[Doru]

Originally Posted by bosanci28

Hello Doru,

hmm,i did not see anyone in the forum talking about this to fix the tranny jolt!,did anyone had this problem and it fix it by doing a coolant flash?

i see the big radiator and at the bottom a small one ,looks that one comes from the tranny the hoses...

you had the same problem? i still don't get it why the coolant radiator ?

thanks

Fmugur chased this problem for a long time. He monitored the temps and other variables with GT1 and INPA. One day he found out that the transmission temp is going up when you slow down/coast, which should not - it should decrease. The heat exchanger of the tranny has a double t-stat if you will. So when it's hot, it opens up the lower part of the radiator to cool the ATF in the heat exchanger (Item #15 in this diagram). But if the lower part of the radiator is gunked up, there is no flow, and subsequently the tranny gets only hotter. At this moment, the tranny will "rev up" (for lack of better explanation/terms) and you feel the "jolt".
If you have this problem, you cannot clean the radiator, no matter how many times you flush it. This is why you want to flush the coolant every 2 years.
Maybe my explanation is lacking, but if I were you, I would give Fmugur a PM to ask him about this. He knows in detail the issue. The radiator is less $$ than what the dealer quoted you. And if you ask my friend, he will also tell you that this is the biggest "known" secret of the cooling system - a very specialized indy told him that, and the indy was surprised that Fmugur actually found the real cure/issue of the tranny "jolt". No bull.

[civdiv99]

Yeah, he applied my transmission thermostat mod as well as the cooling system mod, I believe.

[Doru]

Originally Posted by civdiv99

Yeah, he applied my transmission thermostat mod as well as the cooling system mod, I believe.

Yes, but once the rad was changed, the mod wasn't necessary anymore.

[bscarlett]

I was having the same problem with my E53 and the issue was worse when the transmission was cold. A transmission fluid, filter and software upgrade fixed it!

[burcham2]

might want to try the guibo joint- or in english, the 'flex disk' between the tranny and the driveshaft

[ewebby]

I had something similar, it ended up being a leaking or clogged Oil Seperator that was messing things up. Oil Seperators need replacement around 100k.

[fmugur]

Originally Posted by Doru

Yes, but once the rad was changed, the mod wasn't necessary anymore.

I still have the civdiv's mod in though but yes, the transmission temp dropped after changing the radiator. The high transmission temp was causing the hard downshift from 2-1 and other funny behaviour. The bottom of the radiator is feeding the heat exchanger with cold coolant. If that part is clogged then no cooling through the heat exchanger which results in high transmission temperature.