DCT needs replacement?

[JohnWinemaker]

I have a 2011 335is DCT with 67,000 miles. Yellow cog light came on and went into limp mode. BMW tech drove it three days in a row and could not duplicate the behavior. Error code 0x005A53 DKG:Gearbox overheating:phase red. Fluid sample was withdrawn and found metal filings. Recommendation: 1)DCT replacement for $10,000, 2) Flush for $1500, but just temp fix. The car was never tracked, never driven in stop-go traffic, mostly highway miles. No one knows what caused this DCT to fail. The DCT shifts perfectly, until it over-heats. Most of the time it never over-heats. I have read that it is safer to drain and replace the filters than flush. Is that true? Does the DCT really need to be replaced?

[chris_flies]

Well, I'd start with draining it, replacing the filters, and refilling it. If that saves it, then that's $8,500 saved. Could also be an issue with the cooling lines and whatnot causing the overheating...

[Esteban]

OP, here's a thread in the E90 forum about the 335is DCT overheating, if you haven't already seen it.

[The Wind Breezes]

Originally Posted by JohnWinemaker

DCT

Sounds like your DCT is shitting itself. You can do a filter and fluid change yourself if so inclined. The filter change is the important part. But it won't fix the actual problem, whatever that is.

I have had many issues with the trans overheating while tracking the car but it just delays the hell out of shift requests and reduces power. Never had any warning symbols. If you have warning symbols and only drive the car normally, that is a very bad sign. This trans can typically take a LOT of abuse and live to tell the tale. Yours probably has a intrinsic defect.

[Gangplank]

Originally Posted by JohnWinemaker

I have a 2011 335is DCT with 67,000 miles. Yellow cog light came on and went into limp mode. BMW tech drove it three days in a row and could not duplicate the behavior. Error code 0x005A53 DKG:Gearbox overheatinghase red. Fluid sample was withdrawn and found metal filings. Recommendation: 1)DCT replacement for $10,000, 2) Flush for $1500, but just temp fix. The car was never tracked, never driven in stop-go traffic, mostly highway miles. No one knows what caused this DCT to fail. The DCT shifts perfectly, until it over-heats. Most of the time it never over-heats. I have read that it is safer to drain and replace the filters than flush. Is that true? Does the DCT really need to be replaced?

Originally Posted by Esteban

OP, here's a thread in the E90 forum about the 335is DCT overheating, if you haven't already seen it.

Is you car stock or running a tune? Personally I'd do a flush & replace the filters/pan.

Steve, that thread is a poster child for what's wrong with e90 post. Lots of people with no clue what they are arguing about chiming in about a car with options they don't have. Lol!!

[Gangplank]

This post might be helpful. It seems to point to a faulty sensor as a possible culprit.

https://www.1addicts.com/forums/show...1137094&page=3

(You have to ignore one of the posters in that thread. You'll know when you read it.)

[Esteban]

Originally Posted by Gangplank

Steve, that thread is a poster child for what's wrong with e90 post. Lots of people with no clue what they are arguing about chiming in about a car with options they don't have. Lol!!

Haha, well Josh, after all, it is the E90 forum (as far as having no clue). JK

To be fair, they do mention in that thread that I linked to the DCT could be leaking, changing the fluid and filters, removing the under tray panels to get a good look, typical stuff... but they are discussing the 335is.

Yes, I know the DCT in the 135i and the 335is are the same, but at least it puts the OP in the right forum.

Edit: that thread also provides a link to an ECS DCT transmission service kit.

[zx10guy]

I agree to try the oil and filter change to see what happens. If the problem persists, I would ask the dealership to contact BMW to see if they can do any type of goodwill concession. Even it BMW only covers half of the repair bill, that's still better than $10k.

[Esteban]

Originally Posted by zx10guy

I agree to try the oil and filter change to see what happens. If the problem persists, I would ask the dealership to contact BMW to see if they can do any type of goodwill concession. Even it BMW only covers half of the repair bill, that's still better than $10k.

I have mine checked every year for leaks and so far, almost 8 years later, all is good. Mine has always ran perfectly. Considering what some others have had to deal with (like you), I consider myself lucky. Luck of the Irish is still with me.

PS - glad yours is working well now, Henry.

[zx10guy]

Originally Posted by Esteban

I have mine checked every year for leaks and so far, almost 8 years later, all is good. Mine has always ran perfectly. Considering what some others have had to deal with (like you), I consider myself lucky. Luck of the Irish is still with me.

PS - glad yours is working well now, Henry.

Tell me about it. You are definitely fortunate with your car. My DCT has also been leak free so far. Verified recently when I was under my car doing an oil change.

[Gangplank]

Originally Posted by Esteban

Haha, well Josh, after all, it is the E90 forum (as far as having no clue). JK

To be fair, they do mention in that thread that I linked to the DCT could be leaking, changing the fluid and filters, removing the under tray panels to get a good look, typical stuff... but they are discussing the 335is.

Yes, I know the DCT in the 135i and the 335is are the same, but at least it puts the OP in the right forum.

Edit: that thread also provides a link to an ECS DCT transmission service kit.

Originally Posted by Esteban

Haha, well Josh, after all, it is the E90 forum (as far as having no clue). JK

To be fair, they do mention in that thread that I linked to the DCT could be leaking, changing the fluid and filters, removing the under tray panels to get a good look, typical stuff... but they are discussing the 335is.

Yes, I know the DCT in the 135i and the 335is are the same, but at least it puts the OP in the right forum.

Edit: that thread also provides a link to an ECS DCT transmission service kit.

True, true.

[tock172]

Originally Posted by JohnWinemaker

I have read that it is safer to drain and replace the filters than flush. Is that true?

This belief originated long before dual-clutch transmissions found their way into production cars like the 135i. For the most part, the drain and refill method being safer than a flush applies to an conventional torque-converter automatic transmission with high mileage. It's said that flushing a high-mileage slushbox auto can result in longterm sediment getting dislodged and later causing issues with the valve body and elsewhere, leading to premature failure if the transmission had simply been left along or been given a drain and refill with a new filter.

The drain and refill process is different from a flush in that new fluid isn't continuously circulated, agitating debris and other deposits. With a drain and refill, the old fluid is simply drained out (what's accessible, anyway), and new fluid is added until the unit is full.

I've used the drain and refill practice on numerous high-mileage traditional automatic transmissions, some of which were showing signs of eventual failure. The process always included draining the old fluid, fitment of a fresh filter and filling with new fluid. It never caused any kind of premature failure in my experience or aggravated any pre-existing condition, but keep in mind that a DCT is an entirely different beast.

That being said, when my DCT was discovered to be leaking and was to be fixed under warranty, I paid extra for fresh fluid, as BMW as going to pump the original lifetime fill back in!

[Tenspeed]

Originally Posted by tock172

This belief originated long before dual-clutch transmissions found their way into production cars like the 135i. For the most part, the drain and refill method being safer than a flush applies to an conventional torque-converter automatic transmission with high mileage. It's said that flushing a high-mileage slushbox auto can result in longterm sediment getting dislodged and later causing issues with the valve body and elsewhere, leading to premature failure if the transmission had simply been left along or been given a drain and refill with a new filter.

The drain and refill process is different from a flush in that new fluid isn't continuously circulated, agitating debris and other deposits. With a drain and refill, the old fluid is simply drained out (what's accessible, anyway), and new fluid is added until the unit is full.

I've used the drain and refill practice on numerous high-mileage traditional automatic transmissions, some of which were showing signs of eventual failure. The process always included draining the old fluid, fitment of a fresh filter and filling with new fluid. It never caused any kind of premature failure in my experience or aggravated any pre-existing condition, but keep in mind that a DCT is an entirely different beast.

That being said, when my DCT was discovered to be leaking and was to be fixed under warranty, I paid extra for fresh fluid, as BMW as going to pump the original lifetime fill back in!

I discovered my DCT was leaking around the pan gasket at 35k miles, 2 months before my CPO ran out. They originally were going to do an in place mechatronix module/pan and gasket/fluid replacement until I asked if they were going to affect the mechatronix seal when the replaced the module. Then all of the sudden they decided to drop the transmission and replace that seal as well.

That was the best $50 I ever spent.

One side effect that I discovered a month or so ago from them dropping the transmission was that they didn't torque the differential brace where it bolts to the differential, and it started to rattle on sharp bumps. A torque wrench solved that issue pretty quickly.

[jeca19955]

hi guys , im new here and i need some help with my 135i n55 dct gearbox , for scaning im using rheingold and i have faults with dkg module (gearbox), when i turn on car transmission is not responding and i joystick si not showing in what possition is gearbox(P, N D....) mechatronic was changed already and also programed , PT-can bus is checked and works properly, have someone ideas what can be? i have all fault and can write them. thanks, sorry for my english im german.