DCT transmission leaks - DCT owners please read

[gabeyts]

Hi all,

Long time lurker here, finally bought my own BMW, a 2012 CPO 135i with 29,7XX miles. So, I got this CPO car from a dealer that was a lease from that same dealer. Clean CARFAX and all, and I went in knowing about the N54s HPFP issues, so I felt comfortable getting this CPO 2012 with the N55. I test drove it twice and liked the DCT as well. My long commute in heavy traffic made the decision a no-brainer to me.

After getting the car I started reading these forums even more, trying to find what the common issues with the N55 are after a few years and noticed the usual water pump and oil pan problems, as well as a new one I didn't see before, the DCT leaking.

With this new info I decided to go to the service department and ask for my cars service history. The advisor gave me a printout of something that is supposedly confidential that he isn't supposed to even let me see. Anyways, the huge thing that caught my eye was:

1) Defect code 2800304800 "Leak, double clutch DKG leaking"

at mileage 27,728 on 6/30/15... after the car was returned! The notes I saw on his computer, which he didn't print out, stated that the tech noticed fluids and so the repair was to replace the oil pan, and to be filled with 1 liter of transmission fluid.

So two things I want to highlight with this are:

1) Did the previous owner never notice symptoms with the trans leaking fluid? I am led to believe the answer is NO, so for the rest of you out there with DCT transmissions, I think it is highly important you check for this. It seems that the transmission can be leaking fluid and you wont be able to tell.

2) What are the long term ramifications of the DCT leaking fluid? I only read about a handful of cases of this occurring on the M3 forums, and that there were multiple points of leakage. This is certainly unnerving. I also think the repair the dealer did on mine was a poor attempt, since I know in the M3 the source of leakage were gaskets as well as the mechantronic(?) sleeve and repair/replacement of those components.

As a side note, after starting the car 2 days after I bought it, it had a very long start, about 3-4 seconds, so I am taking it to another dealer to get that looked at (probably the HPFP), and to also check to see if the transmission is leaking fluid since it already has a history of doing so.

I want to hear input from others about the severity of this problem and also to warn everyone that this occurrence may be asymptomatic, as it appears to have been in the case of the car I bought. Anyone with insights to this is greatly appreciated.

PS Sorry if this is in the wrong subforum

[kirkbar]

I had a trans leak on my 2011 DCT and they replaced the bottom pan and gasket and topped off the fluid. This was done under warranty when the car had 47K miles on it. I brought this to the dealership's attention after noticing fluid collection around the pan and on the plastic underbody cover.

Now with 55K on my car and our of warranty, I have noticed another leak. This one from the side cover but not as bad as the bottom leak. Had the car in almost 3 weeks ago and they submitted the case to BMW for review. I have not heard back yet but will call them before weeks end.

My forum research brought up a few of these leaks M3 and 135i as well as a theory on why they are occurring. Seems the screws holding these covers expand and contract with the heat from the exhaust pipes as they are only a few inches away from the trans. Not sure if the BMW fix changes these screws are not.

Not sure if this helps you out or not - but you are not alone.

[sometorque]

DCT leak member #003 checking in. 2011 135i DCT with 74k miles

I took the car in after experiencing a few random trans temp warning lights coming up (Refer to my thread on the issue http://www.1addicts.com/forums/showthread.php?t=1137094)

After looking over the car, they saw a slight leak from the pan and the mechatronic sleeve. It was fixed under CPO warranty. However, I'm still getting the trans temp light pop up for a second or two randomly every few weeks. Car drives normally when the light doesn't come up and the twice it's come up since getting the car back, it's been on and off in a second or two. I'm suspecting a bad sensor so it'll be going back to the dealer this weekend.

Haven't heard of many people with my specific issue with the trans temp warnings (I've had it come up 4 times in total in 6 months of ownership. twice before the leak fix and twice after). Car drives normal 99.9% of the time with no shifting issues, but I'm a bit concerned my specific issue is related to the leak.

We'll see in a few days when I get it to the dealer.

[gabeyts]

Hey guys, thanks for the input.

kirkbar what exactly does submitting the case to BMW entail? That they might help cover costs despite being out if warranty or an engineer is going to look at your case?

sometorque sorry to hear about the problems, since I am obviously still too also under CPO warranty I am also going to seriously consider unloading it before warranty end since it seems replacing these components are just temporary bandaids that offer no permanent solution. I have not had the temp warnings come up yet and it has been pretty hot these last few days and I would have expected it to show up these past few days if any

[sometorque]

Good read on the M-DCT found in the e90 m3. While not the tranny in our cars, they're VERY similar.

http://koti.kapsi.fi/~postimies/BMW/...Drivetrain.pdf

[Dilmorecg]

I had this happen to me recently...'11 with ~55k miles. Mine was leaking bad from the trans pan seal. Luckily I purchased a 3rd party after market warranty and they covered it...now its almost paid itself off.

Looks like its not an uncommon thing. Mine was obvious with the amount of oil around the trans pan...thats why I took it in. No symptoms for me while driving.

[gabeyts]

Originally Posted by Dilmorecg

I had this happen to me recently...'11 with ~55k miles. Mine was leaking bad from the trans pan seal. Luckily I purchased a 3rd party after market warranty and they covered it...now its almost paid itself off.

Looks like its not an uncommon thing. Mine was obvious with the amount of oil around the trans pan...thats why I took it in. No symptoms for me while driving.

Dilmorecg Thanks for sharing your experience. Did the dealer who repaired it explain to you the cause/effect of the leak and what it could mean long term for the car?

[houtan]

I had this issue a couple of years ago. My thread is here: http://www.1addicts.com/forums/showthread.php?t=890006

As it turned out, changing the oil pan gasket didn't fix the leak. Took the car back in and the tech identified the leak to be coming from the gasket where the harness connects to the transmission. Required removal of the transmission to repair.

Dct has performed perfectly before and afrer the repair.

[gabeyts]

houtan Thanks for your reply. If my situation is similar to yours, I am sure them just replacing the pan is just a short term fix. What's the best way to go about telling them to check the gaskets? I don't trust these dealers to do a thorough job of finding the problem and fixing it

[houtan]

It could be just the oil pan gasket which means the leak may be fixed. I would drive the car for a couple thousand miles then take a look at the to see if it's still leaking. If it is, then take the car back in and say it's still leaking.

[sometorque]

Originally Posted by gabeyts

sometorque sorry to hear about the problems, since I am obviously still too also under CPO warranty I am also going to seriously consider unloading it before warranty end since it seems replacing these components are just temporary bandaids that offer no permanent solution. I have not had the temp warnings come up yet and it has been pretty hot these last few days and I would have expected it to show up these past few days if any

Likewise, deathy afraid to have this thing after the warranty ends. I just dropped mine off yesterday at the dealer for the trans temp light for the second time. I'm giving them the benefit of the doubt for the first time, given that they found and fixed the leak.

If they can't solve it after a second visit, I'll be pushing for a new transmission.

[Dilmorecg]

Originally Posted by gabeyts

Dilmorecg Thanks for sharing your experience. Did the dealer who repaired it explain to you the cause/effect of the leak and what it could mean long term for the car?

Nope, they didnt give me a reason why it happened or mention the long term issues. Mine wasnt leaking that long so I dont know if the level got that low.

[Lambobimmer]

I had this issue with my Z4 and I got a new DCT under warranty.

http://e89.zpost.com/forums/showthread.php?t=854783

[AyJay87]

I also had/have a leaky gasket. It was replaced and had the fluid topped off under warranty about 8k mi ago and recently had a look underneath the car this past weekend. To me it looked like it was still there, but nowhere near as bad as before. But it goes without saying, I'm not happy that its still leaking.

[The Wind Breezes]

BMW's fluid pan gaskets are notoriously short-lived. I think they do this kind of thing on purpose to ensure planned obsolescence for the crowd who don't mind driving an older BMW, but won't work on the car themselves.

[e36addict]

90% of the time it's not the oil pan gasket. It's the mech sleeve leaking from the top, and fluid slowly makes its way down and around the case/pan, looking like a pan leak. I've experienced this on many different cars. One of them being my own mother's car. As for my car, I've had the slightest ever seep from the mech sleeve for quite some time, but with 89, almost 90k on it still doesnt leak onto the plastic underbody tray or the ground.

[taranfx]

My mechanic told me i have a DCT leak too. My car has 57k miles and I bought it recently. He's replacing gasket and everything. He was also telling me its common due to heat from cats.

Is there a way to prevent this in future? May be get rid of the Cats? But exhaust pipes would still be pretty hot i believe.

[MONEY]

Originally Posted by e36addict

90% of the time it's not the oil pan gasket. It's the mech sleeve leaking from the top, and fluid slowly makes its way down and around the case/pan, looking like a pan leak. I've experienced this on many different cars. One of them being my own mother's car. As for my car, I've had the slightest ever seep from the mech sleeve for quite some time, but with 89, almost 90k on it still doesnt leak onto the plastic underbody tray or the ground.

Hi Guys,

Recently as of yesterday I have noticed my clutch slipping for the first time specifically in gears 4-5, and I only have 35k miles. My cover on the undercarriage of the tranny, has oil all over it. After doing some research, it seems as though my mechatronic sleeve needs replacing along with the pan and gaskets etc. It seems as though this is an issue with BMW and their DCT's.

Could this be the reason my clutch is slipping? Have I lost enough oil that it is causing my clutch to slip?


Any help will be greatly appreciated!!

[Katkarot]

I can't say for sure but I would fill the oil up and see if the slipping goes away.

I had mechatronic leak which I thought was a oil pan gasket leak so I replace the oil pan gasket, filters and refill the oil.

To fix the mechatronic leak, you have to drop the tranny.

Originally Posted by MONEY

Hi Guys,

Recently as of yesterday I have noticed my clutch slipping for the first time specifically in gears 4-5, and I only have 35k miles. My cover on the undercarriage of the tranny, has oil all over it. After doing some research, it seems as though my mechatronic sleeve needs replacing along with the pan and gaskets etc. It seems as though this is an issue with BMW and their DCT's.

Could this be the reason my clutch is slipping? Have I lost enough oil that it is causing my clutch to slip?


Any help will be greatly appreciated!!

[Happy Jose]

Well I've had a problem with the DCT side plate gasket leaking. The leak was discovered when I took it in for service, I believe two years ago, at around 30K miles. I was totally unaware of it being no CEL warning.

They had to remove the transmission to replace the side plate gasket. I also asked them to replace the gasket or o-rings on the mechatronic sleeve. I don't know if they did or not.

I've removed the plastic over the DCT and checked for leaks about this time last year. It was dry. I noticed above something about a defect code indicating a leak! I have a BMW specific scanner, so I'm going to do a dynamic scan to see if I get any such thing.

Another guy said he got temperature warnings which would greatly bother me. This could be due to the unit low on transmission fluid obviously caused by a leak.

I really like this car, but I'm starting to get tired of its problems. The DCT is a big concern for it's an expensive repair, a replacement for $10K+!

I have a BMW extended warranty with 15 months left on it. I may dump it for a 2020 or 2021 M240i. Money isn't a concern for me, but an unexpected breakdown is. I just don't want to be bothered with unpredictable issues.

[dtla1]

I recently had issues with the Transmission Overheating Warnings, lights, loss of power etc. Really a pain in the ass and unpredictable when it was going to happen. Took the car into a shop, they checked for leaks, checked transmission fluid level and all good. Ran a transmission check test and it came back saying the transmission could not hold all the power. Decided to replace the clutch, ended up being around $4k since I also replaced my oil pan gasket and motor mounts at the same time.

No issues since new clutch, car feels like it makes all the power it's supposed to now where as before it used to feel like it was just slipping when trying to make any sort of power.

[Esteban]

Originally Posted by dtla1

I recently had issues with the Transmission Overheating Warnings, lights, loss of power etc. Really a pain in the ass and unpredictable when it was going to happen. Took the car into a shop, they checked for leaks, checked transmission fluid level and all good. Ran a transmission check test and it came back saying the transmission could not hold all the power. Decided to replace the clutch, ended up being around $4k since I also replaced my oil pan gasket and motor mounts at the same time.

No issues since new clutch, car feels like it makes all the power it's supposed to now where as before it used to feel like it was just slipping when trying to make any sort of power.

Those are big bucks, but at least you got it sorted out.

PS - cheaper than a new DCT, though. lol