Turbo Lag

brocklanders · 04-08-2014, 04:55 PM

After reading a lot of these threads, maybe its a combination of the dsc and the tranny searching. I experience this hesitation from time to time and the only thing I can come up with is to adjust my inputs when I assume its going to happen. My car just broke 1200mls and I just now started playing with the buttons, and I still get the lag with sport button and sport shift. This car is different then what I'm used to and I need to learn how to drive it. I can not wait to take it to the drag strip, hesitation or no it will be the most fun I will ever have in an automatic.

socal135 · 04-14-2014, 11:09 AM

I was driving on the freeway going about 65mph. I had to come to a abrupt stop due to traffic. After a few seconds of pause traffic began to move. I gave my DCT some gas, it took about 4 car lengths before the car decided to move. For a few seconds I almost thought the car had stalled. Is this the nature of the DCT?

Overpar56 · 04-14-2014, 11:38 AM

Quote:

Originally Posted by socal135

I've had a 135is with DCT for over a year. The DCT lag from start to stop is a problem that I encounter daily. This morning I pulled up to a stop sign and stopped. Upon giving the car a moderate amount of throttle, the car moved forward a bit then lagged for about 2 seconds leaving me stranded in the intersection. Instinct makes me want to mash the gas pedal and get out of the intersection, but experience made me quickly realize that all the power would come out in a flurry and I would look like a jackass burning rubber.

Exactly. I have my 135 at the dealer today. I gave them the list of drivability issues and I mentioned the service bulletin from 2012 about the reflash. Let's see if they do it. 4.5 hours in and no call so far. I set the trip odo back to zero so I'll see how many miles they test drive it.

socal135 · 04-14-2014, 03:47 PM

Quote:

Originally Posted by Overpar56

Quote:

Originally Posted by socal135

I've had a 135is with DCT for over a year. The DCT lag from start to stop is a problem that I encounter daily. This morning I pulled up to a stop sign and stopped. Upon giving the car a moderate amount of throttle, the car moved forward a bit then lagged for about 2 seconds leaving me stranded in the intersection. Instinct makes me want to mash the gas pedal and get out of the intersection, but experience made me quickly realize that all the power would come out in a flurry and I would look like a jackass burning rubber.

Exactly. I have my 135 at the dealer today. I gave them the list of drivability issues and I mentioned the service bulletin from 2012 about the reflash. Let's see if they do it. 4.5 hours in and no call so far. I set the trip odo back to zero so I'll see how many miles they test drive it.

Keep me posted!

Overpar56 · 04-14-2014, 04:37 PM

Got it back from the dealer. Yes, it seems fixed with SB 12 09 12. No more lurching. No more laying on the gas and not moving. Hard left or right turns at low speeds doesn't cut the throttle.

What it did do:
Shifts more smoothly in D, S, and M modes. Gear changes are still,fast but seem a bit softer. You don't get that "twack" when it shifts.

I've heard others say that the exhaust is more muted, but I had the windows down and with the PE, I can't tell a difference.

I'll trade off a little slower shifts if the drivability is better and safer. It's still faster than a manual.

CAVU · 04-15-2014, 11:31 AM

Quote:

Originally Posted by socal135

I've had a 135is with DCT for over a year. The DCT lag from start to stop is a problem that I encounter daily.

This is very concerning to me... I was hoping the 135is was immune to this issue. As I consider what could be causing this behavior to develop over time, it seems that the hardware itself is not physically changing, and the software is the same, so perhaps it has something to do with the DCT electronic control "learning" over time and attempting to adjust. It is easy to observe how the throttle response and DCT shift mapping adjust after a few miles of 'enthusiastic' driving. I'm just keeping my fingers crossed that I don't end up with this issue.

Quote:

Originally Posted by Overpar56

Got it back from the dealer. Yes, it seems fixed with SB 12 09 12. No more lurching. No more laying on the gas and not moving. Hard left or right turns at low speeds doesn't cut the throttle.

What it did do:
Shifts more smoothly in D, S, and M modes. Gear changes are still,fast but seem a bit softer. You don't get that "twack" when it shifts.

I've heard others say that the exhaust is more muted, but I had the windows down and with the PE, I can't tell a difference.

I'll trade off a little slower shifts if the drivability is better and safer. It's still faster than a manual.

I'm glad to hear our local dealer was able to get this issue under control. I'd hate to give up the firm nature of our gear changes, but I suppose it's all subjective and relative, not to mention difficult to quantify. I suppose BMW isn't going to divulge exactly what goes into this software revision.

socal135 · 04-15-2014, 11:51 AM

Quote:

Originally Posted by Overpar56

Got it back from the dealer. Yes, it seems fixed with SB 12 09 12. No more lurching. No more laying on the gas and not moving. Hard left or right turns at low speeds doesn't cut the throttle.

What it did do:
Shifts more smoothly in D, S, and M modes. Gear changes are still,fast but seem a bit softer. You don't get that "twack" when it shifts.

I've heard others say that the exhaust is more muted, but I had the windows down and with the PE, I can't tell a difference.

I'll trade off a little slower shifts if the drivability is better and safer. It's still faster than a manual.

That is good news. The dealership has my car right now. I hope they can fix the issue.

Rob Daman · 04-15-2014, 07:02 PM

Quote:

Originally Posted by socal135

That is good news. The dealership has my car right now. I hope they can fix the issue.

Which dealer?

Overpar56 · 04-15-2014, 07:28 PM

Quote:

Originally Posted by RickMsport

This is very concerning to me... I was hoping the 135is was immune to this issue. As I consider what could be causing this behavior to develop over time, it seems that the hardware itself is not physically changing, and the software is the same, so perhaps it has something to do with the DCT electronic control "learning" over time and attempting to adjust. It is easy to observe how the throttle response and DCT shift mapping adjust after a few miles of 'enthusiastic' driving. I'm just keeping my fingers crossed that I don't end up with this issue.

I'm glad to hear our local dealer was able to get this issue under control. I'd hate to give up the firm nature of our gear changes, but I suppose it's all subjective and relative, not to mention difficult to quantify. I suppose BMW isn't going to divulge exactly what goes into this software revision.

My guess is they revised how the clutches engage and put a fraction more delay between upshifts to stop wear and tear and keep warranty costs down. I had it out today and you can tell the upshifts in Sport and manual shift are more muted. But every issue about "dead pedal" seems to be fixed. I actually had to make a hard left across oncoming traffic and it felt like a normal car. No hesitation.

The most noticeable is the 1st to 2nd change. Just doesn't have the same abrupt engagement.

socal135 · 04-15-2014, 09:14 PM

Quote:

Originally Posted by Rob Daman

Quote:

Originally Posted by socal135

That is good news. The dealership has my car right now. I hope they can fix the issue.

Which dealer?

South Bay BMW in Socal.

VR-Tech · 07-23-2017, 04:41 PM

Quote:

Originally Posted by shah269

It's not the engine it's your transmission.
Trade it in for a stick, problem solved.

Silly way of resolving the problem

captain slowly · 07-23-2017, 04:53 PM

Quote:

Originally Posted by VR-Tech

Silly way of resolving the problem

You told him, 2.5 years later!!

VR-Tech · 07-23-2017, 10:34 PM

Quote:

Originally Posted by captain slowly

You told him, 2.5 years later!!

Haha, i just bought a 135is yesterday!!

04-08-2014, 04:55 PM	#45
brocklanders Major 106 Rep 1,428 Posts Drives: the uno, mineral white Join Date: Mar 2010 Location: houston iTrader: (3) Garage List 06 325 [0.00]	After reading a lot of these threads, maybe its a combination of the dsc and the tranny searching. I experience this hesitation from time to time and the only thing I can come up with is to adjust my inputs when I assume its going to happen. My car just broke 1200mls and I just now started playing with the buttons, and I still get the lag with sport button and sport shift. This car is different then what I'm used to and I need to learn how to drive it. I can not wait to take it to the drag strip, hesitation or no it will be the most fun I will ever have in an automatic.
	Appreciate 0 Quote

04-14-2014, 11:09 AM	#46
socal135 Private First Class 6 Rep 162 Posts Drives: Carbon Black 135is Join Date: Oct 2012 Location: Southern Cali iTrader: (0)	I was driving on the freeway going about 65mph. I had to come to a abrupt stop due to traffic. After a few seconds of pause traffic began to move. I gave my DCT some gas, it took about 4 car lengths before the car decided to move. For a few seconds I almost thought the car had stalled. Is this the nature of the DCT?
	Appreciate 0 Quote

04-14-2014, 04:37 PM	#49
Overpar56 Proud AARP member in good standing 28 Rep 635 Posts Drives: Me nuts Join Date: Oct 2013 Location: Skyline, Chile iTrader: (0)	Got it back from the dealer. Yes, it seems fixed with SB 12 09 12. No more lurching. No more laying on the gas and not moving. Hard left or right turns at low speeds doesn't cut the throttle. What it did do: Shifts more smoothly in D, S, and M modes. Gear changes are still,fast but seem a bit softer. You don't get that "twack" when it shifts. I've heard others say that the exhaust is more muted, but I had the windows down and with the PE, I can't tell a difference. I'll trade off a little slower shifts if the drivability is better and safer. It's still faster than a manual. __________________ 2012 135i DCT, Lemans Blue/black leather, PPK1, PE, Stoptech Sport rotors and Sport pads, unhealthy crackles and burbles and an aging demonic driver.
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