Need Help Troubleshooting DCT Issues

[MPACT]

Hey guys, i am having some issues with my DCT. As some background the engine/trans have been out twice and reinstalled (new engines, but same DCT). I am running an AlpineMSS GTS DCT and Stage 2 engine tune.

I am trying to figure out whether I might have a bad sensor, DCT clutches, or I should just swap the whole DCT but I wanted to ask if anyone on the forum has had any of these issues and knows what the problem was.

The symptoms are exhibited on the 3 following scenarios. The car hasn’t thrown any codes.

3 Scenarios:

1. S or D mode, 40+ mph to full panic stop. When I take my foot off the brake after coming to a complete stop, there is a loud BANG, and the car lurches forward a bit and 9 times out of 10 the engine dies. It acts like the clutch disengagement is wrong.

2. Downshifts, engine will blip, but gear doesn’t change. Other times it will do nothing for 2-3 seconds and then downshift.

3. Upshifts, 50-75% throttle, hit the paddle, car will change gear, bog for 2-3 seconds than accelerate again. Doesn’t happen all the time, pretty intermittent.

I asked Alex at Alpine but he had never heard of anything like this before.

Thanks guys!

2022 Update:

I ended up getting this solved. Turns out the DCT filter o-ring was leaking, when I did the SLON DCT pan and full refresh we caught it and got it all dialed in.

[GORDON.M3]

Check for errors with a scan tool. If the transmission is acting up that much then it should be throwing shadow codes.
Clear adaptations, and reset the transmission.
Reflash everything back to stock or reflash the tunes.
Then report your findings.

[bmwfst1]

Make sure the transmission is not leaking oil. Low oil level causes the transmission to do weird things.

[Matheus]

For sure. I had a bad leak in my DCT and it was acting pretty strange. Hesitation in high rpm, slow downshifts (exactly as said). Once i changed the oil and solved the leak DCT went back to normal. As said, check for codes or leaks.

[Patrón]

what are your mods? and have you recently changed the diff fluid?

[MPACT]

So I read the codes using my ESS tuner software and nothing came up. It has a section for Shadow codes so I assume it can read it but there was nothing there. I cleared adaptations but I have also tried reflashing the engine and it made no difference. I don't have the stock DCT files from Alex yet to refresh that.

Fluid level sounds like something I might want to check and maybe type of fluid? It was changed during this last engine swap about 3000 miles ago.

Mods are AFE Stage 2 intake, RE track pipe, Alpine Stage 2 and GTS DCT tune, Corsa Exhaust.

[Impastokitsch]

Sorry to hijack

My car stop rev matching today

Tried clearing adaption data and reflash the alpine map , same symptoms but i have not checked the dct fluid