Overboosting & Maybe Destroyed My Transmission

[ethan7193]

Hi, installed a JB4 on my 2.0t about a month ago. I’ve always had overboosting issues and they evened out after some time and usually only occur from switching to 3rd to 4th gear.

As of today, while going into first gear my car ALWAYS slams itself forward like I’m getting rear ended.

I raced someone today on map4 with an e30 mix and my car was shortly thrown into limp mode afterwards and was fixed after restarting the car and opening the door to do a full restart. My car has been acting weird today switching gears as well.

I cannot upload logs right now, but will be able to in around 30 minutes. Definitely going to get my transmission looked at. Thank you for anyone who helps.

 

[ethan7193]

I haven’t taken many logs and usually get thrown off when trying to log, these are over the past couple days, please let me know is anything is wrong. I’m assuming it’s too late

 

[oddball]

I didn't look at the logs, but slamming into gear means something has gone wrong in the forward clutch. First step would be dropping the pan to see if there's a bunch of material in there. My first thought is a wave plate broke which can't be seen until the trans is torn all the way down - but the clutch material will start wearing real fast which leaves the pan filled with dusty particles.
I'm surprised a 2.0 was able to trash the trans, but, well, a sufficiently emboldened right foot can break all kinds of things!

Are you running a trans tune? With really going after it then you'd want a TCU flash to bring up the line pressure and tweak the shift timing.

 

[Snowwhite]

I’d do an adaptation reset before I dropped the pan.
See this thread

 

[ethan7193]

I didn't look at the logs, but slamming into gear means something has gone wrong in the forward clutch. First step would be dropping the pan to see if there's a bunch of material in there. My first thought is a wave plate broke which can't be seen until the trans is torn all the way down - but the clutch material will start wearing real fast which leaves the pan filled with dusty particles.
I'm surprised a 2.0 was able to trash the trans, but, well, a sufficiently emboldened right foot can break all kinds of things!

Are you running a trans tune? With really going after it then you'd want a TCU flash to bring up the line pressure and tweak the shift timing.

Thank you for the tip. So initially after installing the tune, I did slam into first gear but it went away after some time and isn’t as bad as it is right now, so that’s why I figured it wasn’t an issue. Really not sure but definitely getting it looked at. Just running a simple jb4 and a couple basic performance mods right now.

 

[ethan7193]

I was thinking I could maybe use transmission fluid but I doubt it because it’s only a first gear thing. Also have no idea how I managed to throw the car into limp mode last night

 

[oddball]

It's always worthwhile to look at the fluid- is it full? burnt? chunks floating in it? That's the first diag any time there's transmission issues.

My stinger goes into limp mode when it's wet and I force it to loose traction too much in comfort mode. There's a few different ways the ECU can trip into limp mode - not just mechanical problems.

Like Snowwhite said, disconnecting the battery for a few minutes to force a reset and TCU re-learn is a low-cost test.