[KCLe90]

Hello all, I am in need of some help. I am going to contact XHP about this issue, but want advice from those who may have heard of an issue like this. I've had XHP stage 3 installed for about 2 weeks, and was very deliberate about the break in/ re adapting process. The car worked great in all modes up until now. It is not constant, but sometimes (within the last two days) the car's RPM will dramatically and rapidly increase within gear without increase in speed (typically 75-100% throttle). Afterwards, I can no longer shift in manual mode. I would have to put the shifter back in D-mode, and then put back in M-mode to get it working again. No codes (checked on protool, XHP, and MHD), and adaptations have remained exactly the same. This has happened twice now, once in 4th gear, once in 5th gear. It seems to me like the torque converter is going out. I am currently on 15 psi, and had no issues (even without trans flash) up until now. For now I have disabled the JB4, and have not encountered the issue. If anything, acceleration feels more solid but obviously not faster. Any help or thoughts would be greatly appreciated.

[mweisdorfer]

Originally Posted by KCLe90

Hello all, I am in need of some help. I am going to contact XHP about this issue, but want advice from those who may have heard of an issue like this. I've had XHP stage 3 installed for about 2 weeks, and was very deliberate about the break in/ re adapting process. The car worked great in all modes up until now. It is not constant, but sometimes (within the last two days) the car's RPM will dramatically and rapidly increase within gear without increase in speed (typically 75-100% throttle). Afterwards, I can no longer shift in manual mode. I would have to put the shifter back in D-mode, and then put back in M-mode to get it working again. No codes (checked on protool, XHP, and MHD), and adaptations have remained exactly the same. This has happened twice now, once in 4th gear, once in 5th gear. It seems to me like the torque converter is going out. I am currently on 15 psi, and had no issues (even without trans flash) up until now. For now I have disabled the JB4, and have not encountered the issue. If anything, acceleration feels more solid but obviously not faster. Any help or thoughts would be greatly appreciated.

What's the health & milage of your trans solenoids?

[KCLe90]

All solenoids were replaced about 10K miles ago when the valve body was rebuilt and mechatronic sleeve was replaced. Fluid was also changed.

[Milan]

What fluid did you use? Did you refill it properly?

[rjahl]

Originally Posted by KCLe90

All solenoids were replaced about 10K miles ago when the valve body was rebuilt and mechatronic sleeve was replaced. Fluid was also changed.

Are you running either he MHD checkbox for the Xhp selected?

I think it changes how engine torque is reported to the TCU

[KCLe90]

Originally Posted by rjahl

Are you running either he MHD checkbox for the Xhp selected?

I think it changes how engine torque is reported to the TCU

I did not have the option because I run a JB4 backend flash through MHD.

[KCLe90]

Originally Posted by KCLe90

I did not have the option because I run a JB4 backend flash through MHD.

Let me clarify, only MHD map users have that option.

Originally Posted by rjahl

Are you running either he MHD checkbox for the Xhp selected?

I think it changes how engine torque is reported to the TCU

Originally Posted by KCLe90

Let me clarify, only MHD map users have that option.

Yeah, that's obviously a good place to start.

I'd give flash-only tuning a try before exploring any other in-depth/expensive options with respect to diagnosis.

[rjahl]

Originally Posted by FCobra94

Yeah, that's obviously a good place to start.

I'd give flash-only tuning a try before exploring any other in-depth/expensive options with respect to diagnosis.

I've been out of the Xhp loop for some time so I don't know what logging options they still have but you could certainly load up TestO and log the transmission.

By watching the engineRPM, input shaft speed output shaft speed and engine torque, you'll get a good idea of the problem.

You won't find any pressure values as the TCU only models pressure, no pressure sensors to be found.

[KCLe90]

Update: the transmission flash has been removed for a little while now. Transmission shifting seems to just get harsher and hesitate more often. The transmission often has weird shifts under load and has slipped in every gear except for 6th. Still no codes. Torque converter going out??

[mweisdorfer]

Originally Posted by KCLe90

Update: the transmission flash has been removed for a little while now. Transmission shifting seems to just get harsher and hesitate more often. The transmission often has weird shifts under load and has slipped in every gear except for 6th. Still no codes. Torque converter going out??

Why not just goto stage 2.

Did you change out the sleeves and bumpers while you were in there doing the solenoids?

Any codes?

[KCLe90]

Originally Posted by mweisdorfer

Why not just goto stage 2.

Did you change out the sleeves and bumpers while you were in there doing the solenoids?

Any codes?

No codes. The car now slips in every gear with the exception of 6th gear. This typically happens between 50-100% throttle. Hesitation and surging is almost guaranteed around 30% throttle in the 2K-3K rpm band. (Keep in mind this is still on stock flash (XHP completely uninstalled)). Those were replaced by the shop who did the work, the valve body was completely overhauled. I would go stage 2, but since it seems like no matter what I have a mechanical issue and I'm a broke college student, so it doesn't seem like a worthy method of testing lol.

[whyzee125]

Originally Posted by KCLe90

No codes. The car now slips in every gear with the exception of 6th gear. This typically happens between 50-100% throttle. Hesitation and surging is almost guaranteed around 30% throttle in the 2K-3K rpm band. (Keep in mind this is still on stock flash (XHP completely uninstalled)). Those were replaced by the shop who did the work, the valve body was completely overhauled. I would go stage 2, but since it seems like no matter what I have a mechanical issue and I'm a broke college student, so it doesn't seem like a worthy method of testing lol.

That sucks, but obviously as you know there's an issue with your trans. Thankfully these transmissions are generally rock solid and are a dime a dozen so I'd buy a used one for ~$350 and have it swapped in. Be sure to use Lifeguard 6 or Mercon SP ONLY.

[mweisdorfer]

Originally Posted by KCLe90

No codes. The car now slips in every gear with the exception of 6th gear. This typically happens between 50-100% throttle. Hesitation and surging is almost guaranteed around 30% throttle in the 2K-3K rpm band. (Keep in mind this is still on stock flash (XHP completely uninstalled)). Those were replaced by the shop who did the work, the valve body was completely overhauled. I would go stage 2, but since it seems like no matter what I have a mechanical issue and I'm a broke college student, so it doesn't seem like a worthy method of testing lol.

I would consider replacing the torque converter, if the valve body, sleeves, and solenoids have been replaced.

Are you sure they put enough trans fluid in the pan at 100 degrees F? If the pan is low, it will cause the trans to do what you are saying.

I use Amsoil Transmission Fluid and have been using it for 150,000 miles! No issues.

You can buy an Amsoil membership and save $$$ on top quality synthetic oil etc., for your 335i.

Amsoil makes every single fluid for your car.

[blown07]

Originally Posted by mweisdorfer

\

Are you sure they put enough trans fluid in the pan at 100 degrees F? If the pan is low, it will cause the trans to do what you are saying.

This was my thought as well.

[KCLe90]

Originally Posted by mweisdorfer

I would consider replacing the torque converter, if the valve body, sleeves, and solenoids have been replaced.

Are you sure they put enough trans fluid in the pan at 100 degrees F? If the pan is low, it will cause the trans to do what you are saying.

I use Amsoil Transmission Fluid and have been using it for 150,000 miles! No issues.

You can buy an Amsoil membership and save $$$ on top quality synthetic oil etc., for your 335i.

Amsoil makes every single fluid for your car.

I'm going to try first resetting adaptations. After that, I'll check fluid. If both of those are fine, I'll take a look inside the trans. I'm not able to find any torque converters for the transmission though, so if any of y'all have any advice on what to do about that please let me know. Have a happy thanksgiving everyone.

[mweisdorfer]

Originally Posted by KCLe90

I'm going to try first resetting adaptations. After that, I'll check fluid. If both of those are fine, I'll take a look inside the trans. I'm not able to find any torque converters for the transmission though, so if any of y'all have any advice on what to do about that please let me know. Have a happy thanksgiving everyone.

You can buy a remanufactured one. Use BMWFANS.info to get the part number.

[Red_Bean_Bun]

We just had a similar problem. Turned out to be a clogged ATF filter.

[blown07]

Originally Posted by Red_Bean_Bun

We just had a similar problem. Turned out to be a clogged ATF filter.

What was the filter clogged with? I would think if there is enough clutch material to clog the filter the tranny would be toast anyway.

[Spacecpe]

I would recommend getting the extra adjustments on xhp and lower the torque demand between shifts and see how that works

[KCLe90]

Problems keep getting worse. 4th to 5th will rarely shift without slipping, and I get a pulsation like fee when accelerating at any throttle between 2.7K and 3.6K. (Will try to upload a photo of data log).

[feuer]

If needed I have 2010 AT with 75k for sale.