DCT overheated - Solved?

[StripclubDJ]

Originally Posted by MajorBob

HI guys, I don't mean to hijack the thread but you seem skilled at diagnosing and working on the DCTs and I may be dropping mine for the 3rd time . This time to replace the combination temp/ clutch speed sensors. Getting codes 5A58, 5A76 and 5A73 and this seems like the most likely cause. Curious if you agree or if there is something else I should check first? Also… Does anyone have the Clutch removal tool they would rent out? Happy to pay a reasonable amount and return when the job is done.
Thanks!

Pm me

[hfm]

Any bay area shops w/ good DCT experience?

[StripclubDJ]

Originally Posted by hfm

Any bay area shops w/ good DCT experience?

Not that I know of

[Helmsman]

After several month without the friggin code...it turned up again. No code on the replaced aux water pump, cooling system seem to be running fine. This is a tricky one...

[spammysammich]

Originally Posted by Helmsman

After several month without the friggin code...it turned up again. No code on the replaced aux water pump, cooling system seem to be running fine. This is a tricky one...

Do you recall the conditions and any notable behaviors when the warning popped up? I went on a pretty hard 8 hour total drive in 90f weather a while back and didn't have any issues besides the persistent o-ring weep that I've been tracking since February. I do have that recurring aux water pump code but it doesn't trigger any lights.

[Helmsman]

Originally Posted by spammysammich

Do you recall the conditions and any notable behaviors when the warning popped up? I went on a pretty hard 8 hour total drive in 90f weather a while back and didn't have any issues besides the persistent o-ring weep that I've been tracking since February. I do have that recurring aux water pump code but it doesn't trigger any lights.

Hey man,

similar to others really i.e. typically at low speed (where I assumed water pump/coolant should help compensate for lack of air cooling). Did a 200 mile round trip/high way during the weekend without issues.

Missed your mentioned o-ring leakage, what sealing is this?

[spammysammich]

The o-ring sandwiched between the thermostat and the transmission body. Probably gone flat over time. I doubt it was swapped out at the last full transmission service at 88k miles.

[Helmsman]

Originally Posted by spammysammich

The o-ring sandwiched between the thermostat and the transmission body. Probably gone flat over time. I doubt it was swapped out at the last full transmission service at 88k miles.

Ah, got it. Had my Tstat replaced together with fluid and filters some year ago, and yes believe I had some weep there as well. Wouldn't worry if tiny.

[Helmsman]

Pls see April 19th update on first page.

[omgzirra_exe]

Originally Posted by Helmsman

Pls see April 19th update on first page.

have you considered it might be the oil pump in the dct?

there's a plastic unit in there that could be causing issues. i think deansbimmer refereed to it as a anti-return check valve and a venturi pump or sucking jet pump?

what a name.. lol anyways it could be a factor. maybe you might just need a full service on the DCT with all the soft seals and inspection..


p/n: 28107842849

[Helmsman]

Originally Posted by omgzirra_exe

have you considered it might be the oil pump in the dct?

there's a plastic unit in there that could be causing issues. i think deansbimmer refereed to it as a anti-return check valve and a venturi pump or sucking jet pump?

what a name.. lol anyways it could be a factor. maybe you might just need a full service on the DCT with all the soft seals and inspection..


p/n: 28107842849

Saw that interesting thread. However the box is only 40k calm miles old so have difficulties to believe anything is worn out really. Also, the code comes up very seldom since I replaced the aux coolant pump so tend to believe its some other krux.

[GORDON.M3]

Have you replaced the PN: 28107842838?

I was having some downshifting issues and the transmission was not smooth at all even after a full DCT service + upgraded pan. Then I replaced this part @ 60k miles and the transmission was shifting normally again just like it was when I got it at 30k miles.

I took a look at the ball inside of the jet suck pump and it was very much pitted and looked like it was getting old as the plastic had completely discolored.

[Helmsman]

Originally Posted by GORDON.M3

Have you replaced the PN: 28107842838?

I was having some downshifting issues and the transmission was not smooth at all even after a full DCT service + upgraded pan. Then I replaced this part @ 60k miles and the transmission was shifting normally again just like it was when I got it at 30k miles.

I took a look at the ball inside of the jet suck pump and it was very much pitted and looked like it was getting old as the plastic had completely discolored.

Thanks mate, no haven't replaced that one. Thing is that the DCT code started to show already at 25-30k miles useage of the box (replaced when car done 20k miles). And code comes up really intermittent, can be months inbetween. Had fluid, both filters and pan replaced 10k miles ago.
Checking clutch pressure, control valves etc (Protool) it seems to align nicely with the spec's (also provided by the box/read by Protool).

[Helmsman]

Replaced the rpm/temp sensor, seems successful. Before and after pictures below where one clearly see the clutch temp isn't aligned with the other DCT temp sensor. These 114C doesn't trig the code, but it coul jump up 150-180C when it did.
The rpm sensor are typically offset/higher with a few deg C prior everything is heated up. Guessing this has to do with that it is placed in the top of the box and get heated air rather than beind dipped in the fluid.
Anyway, first drive indicates its better than it has been for a long time, so far so good.

[Redd]

Glad to hear you finally resolved this issue! It's been a while.

[Helmsman]

Originally Posted by Redd

Glad to hear you finally resolved this issue! It's been a while.

Thanks Eric, and for your inputs to the process too!

Yeah, lost track of how many years it is since the bloody code turned up first time.
Dealers simply could not diagnose it which is strange, one must assume they have a sensor reader as well. The dealer that finally got the job to replace the sensor seems to have done a good job, very pleased with them being a smaller one outside of town.

Btw they also cleared adaptation and ran through the complete gear/clutch adjustment/relearning. Said this was needed (although I reset with Protool) and believe I can feel a difference.

Cheers
Nik

[Aarrdyy]

Sorry to update this post all this time later, but just wanted to share my thoughts as I recently had the same exact issue with my 2013 E92 M3 DCT 40K miles. Found this post super useful, especially testing via ProTool on the temps.

The warning came up three times in total before I started looking at it and seemed to get progressively worse and not intermittent like yours. When the warning does appear, it only happens after about 40 minutes of driving and when I'm in slow-moving traffic. It first happened when going into reverse and the gearbox became jerky. I immediately turned the car off and straight back on and the warning went away and did not appear again for another two weeks. Where the same happened and then it seemed to happen day after day with the same drive. Eventually it went from phase yellow, to phase red and then finally to phase black while I was trying to troubleshoot.

Reading the codes, it gave me three errors at the beginning: 5A58 - Spray-off sensor: electrical defect, A6D1 - Additional Water Pump and the Phase Yellow temp warning. Cleared the codes and never got 5A58 back.

Thankfully, I found this post and got ProTool to do some diagnosing. Checked for leaks, checked for anything blocking the dct cooler and luckily ProTool showed me the temp at idle for clutch oil was sat about 10-20 degrees c higher than all the other temps, and when I drove it somewhat hard and that difference would just become bigger as well as spiking randomly. At one point it hit over 200 degrees c.

I also got quite lucky with finding this blog post: https://www.munichpower.co.uk/bmw-an...rature-sensor/ where this specialist (Jim) actually had documented the issue and had proof of fixing this issue on multiple cars. He said 90% of the time its the temp sensor inside the gearbox. His shop was only 20-30mins from me so booked the car in. He swapped the temp sensor in a day as well as replacing the aux water pump and doing a dct service. Do note, the car already had a dct service less than 6 months ago, but since the gearbox was coming out, I thought why not.

Had the car back now a couple of weeks done the exact same drive multiple times that triggered it before and driven in 30+ degrees c weather in stop and start traffic and its been faultless. I have read the codes and even the A6D1 code is gone.

Since multiple of us who have had this issue also have had the A6D1 code first then get the dct temp sensor fault down the line. It is my belief that when the aux pump becomes faulty, it must somehow make the temp sensor inside the gearbox also become faulty. This explains why when the aux pump is replaced, it helps the issue but does not cure it as the damage is already done to the sensor. That is a complete guess though.

Anyways, I will bring this long-winded post to a close now, hopefully the next person also finds this useful and thank you again to everyone before me who investigated and wrote up their issue.

TLDR: If you have the issue get ProTool or BMW software to read the temps on the clutch oil and engine oil compare the difference at idle and under load. If there are unexplained differences, most likely the temp sensor and yes the gearbox has to come out to have this replaced.

[Helmsman]

Originally Posted by Aarrdyy

Sorry to update this post all this time later, but just wanted to share my thoughts as I recently had the same exact issue with my 2013 E92 M3 DCT 40K miles. Found this post super useful, especially testing via ProTool on the temps.

The warning came up three times in total before I started looking at it and seemed to get progressively worse and not intermittent like yours. When the warning does appear, it only happens after about 40 minutes of driving and when I'm in slow-moving traffic. It first happened when going into reverse and the gearbox became jerky. I immediately turned the car off and straight back on and the warning went away and did not appear again for another two weeks. Where the same happened and then it seemed to happen day after day with the same drive. Eventually it went from phase yellow, to phase red and then finally to phase black while I was trying to troubleshoot.

Reading the codes, it gave me three errors at the beginning: 5A58 - Spray-off sensor: electrical defect, A6D1 - Additional Water Pump and the Phase Yellow temp warning. Cleared the codes and never got 5A58 back.

Thankfully, I found this post and got ProTool to do some diagnosing. Checked for leaks, checked for anything blocking the dct cooler and luckily ProTool showed me the temp at idle for clutch oil was sat about 10-20 degrees c higher than all the other temps, and when I drove it somewhat hard and that difference would just become bigger as well as spiking randomly. At one point it hit over 200 degrees c.

I also got quite lucky with finding this blog post: https://www.munichpower.co.uk/bmw-an...rature-sensor/ where this specialist (Jim) actually had documented the issue and had proof of fixing this issue on multiple cars. He said 90% of the time its the temp sensor inside the gearbox. His shop was only 20-30mins from me so booked the car in. He swapped the temp sensor in a day as well as replacing the aux water pump and doing a dct service. Do note, the car already had a dct service less than 6 months ago, but since the gearbox was coming out, I thought why not.

Had the car back now a couple of weeks done the exact same drive multiple times that triggered it before and driven in 30+ degrees c weather in stop and start traffic and its been faultless. I have read the codes and even the A6D1 code is gone.

Since multiple of us who have had this issue also have had the A6D1 code first then get the dct temp sensor fault down the line. It is my belief that when the aux pump becomes faulty, it must somehow make the temp sensor inside the gearbox also become faulty. This explains why when the aux pump is replaced, it helps the issue but does not cure it as the damage is already done to the sensor. That is a complete guess though.

Anyways, I will bring this long-winded post to a close now, hopefully the next person also finds this useful and thank you again to everyone before me who investigated and wrote up their issue.

TLDR: If you have the issue get ProTool or BMW software to read the temps on the clutch oil and engine oil compare the difference at idle and under load. If there are unexplained differences, most likely the temp sensor and yes the gearbox has to come out to have this replaced.

Good thing that you got it sorted! Me? Fiddled around with trial diagnoses for bloody years before I eventually nailed it. Shame the various BMW shop didn't use Protool while I had warranty...tossers.

Cheers