5HP24 problems after rebuild

[jicaino]

Hey! I'm taking over diagnosing what's up with a friend's car. He took it to a tranny shop, the car had a couple of minor issues and it would go into limp mode when driven somewhat "hard", the usual coolant/atf exchanger symptoms for ATF overheating, the shop rebuilt the tranny and supposedly opened up and updated the converter internals.

Now, the car accelerates fine in 1st, when it goes into 2nd it feels as if somebody would be braking hard and the tires screech while the car refuses to keep going forward. If you manually select 1st or 3rd it goes forward fine but if it dowshifts into 2nd suddenly it feels as if the car hit a wall and no mater how much gas you give it, it shudders and refuses to move forward. Reverse is fine. There's a code for "revolutions with the car still" code alsp reported as Stall Speed or speed sensors (3B). I'm not auto transmission expert, my knowledge is pretty basic about them slushboxes, but it feels like there's a solenoid or something acting up. I will be checking the wiring and such, but I'd love some input as to what should I test/inspect.

I couldn't get any of my scanners to read live data on the EGS, and the IKE had a code saying "EGS line disturbed".

Thanks in advance

(The car is a DN61 car, built in 9/98)

[ross1]

Somebody F'ed up the valve body. Not gonna end well if driven this way.

[TiesTorN]

valve body problem... probably a bad solenoid.

I was having erratic behaviour with 1st gear, similar to yours. tried pulling out all the solenoids, plugged a 12v supply to them and tossed them in the ultrasonic cleaner. continuosly activated & deactivated them while the machine was operating. that way everything inside got cleaned.

this was 5 years ago, still working fine.

[jicaino]

Somebody F'ed up the valve body. Not gonna end well if driven this way.

The only driving done was limping the car in 1st out of the "transmission specialist" 's shop to my friend's. It was stressful as f...


valve body problem... probably a bad solenoid.

I was having erratic behaviour with 1st gear, similar to yours. tried pulling out all the solenoids, plugged a 12v supply to them and tossed them in the ultrasonic cleaner. continuosly activated & deactivated them while the machine was operating. that way everything inside got cleaned.

this was 5 years ago, still working fine.

I've not drop the pan still. Got 2 hours of physical wiring check plus DIS diagnostics and then INPA activations and checkings.

The only thing other than the valve body (which is also my main theory) that I find suspect is the output speed sensor.

At one point DIS prompted a message stating that some transmission issues are due to the Ike as a gateway... I guess I'll be dropping the pan and removing the valve body, solenoids and harness. Solenoids checks fine for activation/deactivation but they could be installed with a pinched or damaged o-ring... or the valve body assembled with a missing or cracked bump valve (those rubbery cones that goes behind the plate and gasket in the main valve body plate, the larger part. Sorry I'm no auto transmission educated re part names and such

[wayneawh]

It's worth checking if the harness (inside the oil pan) itself is having bad connections.
I did my 5hp24 rebuild on 2019 and soon after that I have strange gear shifting plus the temperature sensor going bad (ATF read 60deg C at cold start).
After verifying with temp gun and checking ATF-coolant HE, it was confirmed the temp sensor was kaput.
The valve body connectors were also very cooked and brittle so that contributed to bad connections.
Bite the bullet and bought a new harness from FCP euro and everything was fixed in one afternoon.
$170
https://www.fcpeuro.com/products/bmw-auto-trans-wire-harness-a5s440z-24341423719

[jicaino]

It's worth checking if the harness (inside the oil pan) itself is having bad connections.
I did my 5hp24 rebuild on 2019 and soon after that I have strange gear shifting plus the temperature sensor going bad (ATF read 60deg C at cold start).
After verifying with temp gun and checking ATF-coolant HE, it was confirmed the temp sensor was kaput.
The valve body connectors were also very cooked and brittle so that contributed to bad connections.
Bite the bullet and bought a new harness from FCP euro and everything was fixed in one afternoon.
$170
https://www.fcpeuro.com/products/bmw-auto-trans-wire-harness-a5s440z-24341423719

Very good input, thanks. I was wondering about that harness too, didn't know it came as a spare. Will definitely keep an eye at the condition of those.

Did you rebuild your transmission yourself? Could you point me to a repair manual for the 5hp24? Thanks in advance

[wayneawh]

I am not equipped enough to do the rebuild so I sent it to a local shop to do it.
Torque converter was also replaced at the same time along with rear main seal.