DCT issue - First car popped out of gear, now I smell clutch

[Daxos]

A while back I started encountering an issue with my 16 M4. I posted a thread but since then symptoms have changed or progressed. You can find the original thread here:

http://f80.bimmerpost.com/forums/sho....php?t=1309748

To summarize, I have a 16 M4 DCT. It has the VF Hex stage 2 tune, TCU tune, VRSF charge pipes, Akrapovic Evo exhaust and Akra downpipes, AFE filter, charcoal filter removal and Dinan heat exchanger. The car has not been on a dyno but from everything I've read on here it should be right around the 500whp mark.

My initial problem was the car seemingly popping out of gear on WOT pulls, usually in 3rd and 4th gear. This issue didn't occur all the time, just occasionally, but enough for me to be worried and bothered by it.

My shop has reset the TCU and clutch ECU's to let the car re-adapt and the car hasn't popped out of gear since, but instead I am now smelling the clutch occasionally. This doesn't even just happen on WOT pulls. The other day it happened being very light on the throttle in 5th gear at around 80mph, so something is definitely wrong.

I'm the first owner of the car. It is currently at 5500 miles and has been driven as stated in the manual until the break in service. I haven't been to a drag trip or track, have never used launch control or kickdown.

Since noone else with similar mods and power levels to my car has reported any issue like this I'm wondering if my clutch is defective.
My shop indicated it sounds like I might need clutch packs to address the issue. I've researched clutch packs a bit and it sounds like either SSP or Dodson are the places of choice for this, though I haven't decided on what to do yet.

Any feedback is appreciated.

[dzvero]

First thing I notice :

Originally Posted by Daxos

The other day it happened being very light on the throttle in 5th gear at around 80mph, so something is definitely wrong.

There is definitely something wrong , maybe with you light throttle doesnt equal to 5th gear at 80 mph

[EALm4]

Do you have any way to pull a data log from the occurrence or to continuously log to monitor this? I had a similar occurrence but after reviewing the log it was just wheel spin.

I believe the signs of a slipping clutch are an upshift in gear associated with a very high sharp increase in RPMs.

I've never heard of being able to smell the clutches though.

[A418t81]

Can't smell any clutch with the DCT, the clutch baskets are in an oil bath.

[Daxos]

Originally Posted by EALm4

Do you have any way to pull a data log from the occurrence or to continuously log to monitor this? I had a similar occurrence but after reviewing the log it was just wheel spin.

I believe the signs of a slipping clutch are an upshift in gear associated with a very high sharp increase in RPMs.

I've never heard of being able to smell the clutches though.

This sounds exactly like what my car was doing when it "popped out of gear". All of the sudden there was a complete loss of power yet the RPM's increased quickly. I immediately let off the gas, and the car continued to drive just fine afterwards.

This issue hasn't happened since the TCU/Clutch ECU reset to re-adapt, but now there's this weird smell which I thought was the smell of clutch.

[EALm4]

Originally Posted by Daxos

This sounds exactly like what my car was doing when it "popped out of gear". All of the sudden there was a complete loss of power yet the RPM's increased quickly. I immediately let off the gas, and the car continued to drive just fine afterwards.

This issue hasn't happened since the TCU/Clutch ECU reset to re-adapt, but now there's this weird smell which I thought was the smell of clutch.

From the time you started up the car to when the occurrence happened, how long was it? 10-15 minutes or a hour into your commute? No drivetrain or chassis malfunctions, correct? Traction control on or off?

Just to be clear, this occurs during WOT going 3rd into 4th? If you had to estimate, how high do you think the RPMs went up? Did this happen every time prior to the TCU reset?

There are so many factors to take into account such as how hard you're actually on the throttle, boost, rpm, etc... The DCT system is a whole other beast itself. Pretty hard to tell without a log

I'll share my data log of a similar occurrence. Basically same thing WOT 3rd into 4th. Shifted at 6294 and went into 4th at 6397. Felt horrible like something was very wrong but after reviewing the log it was just some wheel spin especially in the road/tire conditions I was in. This was only JB4 Map1 and given the amount of boost running the clutch would have had to be completely failing to slip at those boost levels.

I'd be willing to bet it's just a tune issue or just wheel spin. I wouldnt sweat it that much. But if you're looking for a reason to get some Dodson clutches.... might as well

[Daxos]

I was trying to avoid having to buy clutch packs

When the car seemingly popped out of gear it was once after about a 30 minute highway drive with some stop and go traffic, another time after a 2 hour weekend drive. No malfunctions whatsoever, and traction control was on. It was relatively cold outside (below 50F if I remember right) the times that it did happen.

What precisely happened the last time it occurred it was around 60 degrees F, after a 40 minute mixed highway driving, heading onto a very long offramp going WOT in 4th. Around 5k+ RPM the car just suddenly revved up, completely loss of power. I let go of the gas immediately and it drove fine afterwards. The thing is, if I remember right every time this happened I had not even attempted to change gears yet.

I don't think the rpm's went over 6.5K as I was quick to let off the throttle.
During every occurrence of this happening the roads were dry, tires were up to temp. I also have wider tires (265/295 MPSS) mounted which have only around 500 miles on them so I have my doubt it is a traction issue.

Since the last time I took the car to my shop and a clutch re-adaptation was set this specific issue hasn't happened anymore, though now there's the symptom of the smell that I've described, which to me, smells very strongly like clutch. My shop even said when they first try to move the car in their parking lot they smelled clutch and the car was stuttering in first gear, which is something I still observe on a daily basis when reversing (the feel of slipping clutch).

I might try to get into touch with VF Engineering once more, maybe they can chime in if you think it might have anything to do with the tune and not the clutch.

Thank you for your help so far.

[Daxos]

So at this point I'm at a loss on what to do. I've heard from two sources now that the smell I noticed cannot be caused by the clutch. Since the last clutch adaptation reset the car has not popped out of gear again.

How would you guys proceed to get this figured out? I don't want to spends $$$ on clutch packs unless I'm certain my issue will be addressed by this upgrade.

[Who's on first]

Was there a sound, when I popped out of gear... or just hold the RPM's... then the power started coming back on?

[Fake News 2017]

How did I ever guess this car had a tune in it just from the title. I know you guys are going to flame but geez! Wanna play? Gotta pay!!!
#nevergonnalearn

[Daxos]

Originally Posted by Who's on first

Was there a sound, when I popped out of gear... or just hold the RPM's... then the power started coming back on?

There was no sound. The car just increased in RPM's really quickly (as if not in gear so no road resistance against the wheels).

I immediately let off the gas. A second later I stepped back on the gas and the car continued driving just fine.

[Sleeper]

Originally Posted by TypeM4

How did I ever guess this car had a tune in it just from the title. I know you guys are going to flame but geez! Wanna play? Gotta pay!!!
#nevergonnalearn

Thanks for the totally useless contribution.

[Daxos]

Originally Posted by TypeM4

How did I ever guess this car had a tune in it just from the title. I know you guys are going to flame but geez! Wanna play? Gotta pay!!!
#nevergonnalearn

Did you read anything I've posted, at all?

[Who's on first]

Originally Posted by Daxos

There was no sound. The car just increased in RPM's really quickly (as if not in gear so no road resistance against the wheels).

I immediately let off the gas. A second later I stepped back on the gas and the car continued driving just fine.

Mine does this.

I think there's a torque limiter. Couple second delay... RPM's hang... then BAM.. power back on.

The car is not slipping out of gear... that would be violent.

[Fake News 2017]

Originally Posted by Daxos

Did you read anything I've posted, at all?

No, just in a pissy mood and needed to vent about something...

[Daxos]

Originally Posted by Who's on first

Mine does this.

I think there's a torque limiter. Couple second delay... RPM's hang... then BAM.. power back on.

The car is not slipping out of gear... that would be violent.

I'm not sure this is what is happening in my car.
Say I'm WOT in 4th gear at 5K RPM, all of the sudden the RPM's jump up to 6K or higher but NO power whatsoever is delivered. So the RPM's don't hang, they actually keep rising while my foot is still on the gas, yet the car is slowing down as if it was in neutral.

When I then just get on the gas again it drives just fine.

[Fake News 2017]

Originally Posted by Sleeper

Thanks for the totally useless contribution.

It wasn't totally useless, made me feel better

[SSPKris]

Originally Posted by Daxos

I was trying to avoid having to buy clutch packs

When the car seemingly popped out of gear it was once after about a 30 minute highway drive with some stop and go traffic, another time after a 2 hour weekend drive. No malfunctions whatsoever, and traction control was on. It was relatively cold outside (below 50F if I remember right) the times that it did happen.

What precisely happened the last time it occurred it was around 60 degrees F, after a 40 minute mixed highway driving, heading onto a very long offramp going WOT in 4th. Around 5k+ RPM the car just suddenly revved up, completely loss of power. I let go of the gas immediately and it drove fine afterwards. The thing is, if I remember right every time this happened I had not even attempted to change gears yet.

I don't think the rpm's went over 6.5K as I was quick to let off the throttle.
During every occurrence of this happening the roads were dry, tires were up to temp. I also have wider tires (265/295 MPSS) mounted which have only around 500 miles on them so I have my doubt it is a traction issue.

Since the last time I took the car to my shop and a clutch re-adaptation was set this specific issue hasn't happened anymore, though now there's the symptom of the smell that I've described, which to me, smells very strongly like clutch. My shop even said when they first try to move the car in their parking lot they smelled clutch and the car was stuttering in first gear, which is something I still observe on a daily basis when reversing (the feel of slipping clutch).

I might try to get into touch with VF Engineering once more, maybe they can chime in if you think it might have anything to do with the tune and not the clutch.

Thank you for your help so far.

What you are experiencing is clutch slippage. The transmission senses slip while driving and aborts the gear. The transmission will automatically select the next gear available depending on throttle position. The burning clutch smell you are experiencing is actually burning clutch. The reason you smell the clutch is because there is an atmospheric vent in the top of the transmission. This will migrate into the cabin, and this is what you are smelling. One of the biggest issues of clutch failures is the JB4 unit. The JB4 unit will manipulate the torque signal to the transmission. The ECU tells the transmissions computer to apply clamping pressure to the clutch basket depending on engine torque. The signal is manipulated and the clutch slips and burns over time. The driver will never feel the results of the "slipping" until it is too late. The JB4 is useless on dual clutch cars unless you are using it for the back end flash only.

SSP

[Daxos]

Thank you for the feedback. Just speculating here, since my car has the VF Engineering Stage 2 Hex tune would removing it address the issue or is it too late for that and the car will need a clutch replacement or upgrade regardless?

[Who's on first]

Originally Posted by Daxos

Thank you for the feedback. Just speculating here, since my car has the VF Engineering Stage 2 Hex tune would removing it address the issue or is it too late for that and the car will need a clutch replacement or upgrade regardless?

You should post this in their thread (VF's)...

[shiv.nandak]

Originally Posted by SSPKris

What you are experiencing is clutch slippage. The transmission senses slip while driving and aborts the gear. The transmission will automatically select the next gear available depending on throttle position. The burning clutch smell you are experiencing is actually burning clutch. The reason you smell the clutch is because there is an atmospheric vent in the top of the transmission. This will migrate into the cabin, and this is what you are smelling. One of the biggest issues of clutch failures is the JB4 unit. The JB4 unit will manipulate the torque signal to the transmission. The ECU tells the transmissions computer to apply clamping pressure to the clutch basket depending on engine torque. The signal is manipulated and the clutch slips and burns over time. The driver will never feel the results of the "slipping" until it is too late. The JB4 is useless on dual clutch cars unless you are using it for the back end flash only.

SSP

I bet there is a couple of JB4 users reading your post and craping their pants.

[Daxos]

Originally Posted by shiv.nandak

I bet there is a couple of JB4 users reading your post and craping their pants.

Just to clarify but I do not have a JB4. I have the Hex Stage 2 tune from VF Engineering.

I'm also not trying to put blame on anything or anyone. Just trying to find out what's wrong with my car and evaluating my options on how to go about fixing it.