Turbo Lag

[cvandenhaute]

From the description given from Patricksr, it looks more like the issue comes from the nature of the DCT. That was driving me nuts in Chicago Stop/Go traffic in Chicago on my '03 VW R32 (with DSG), not sure there are many ways to fix that, I believe it is the nature of these gearboxes when associated with a torque y engine...

[MightyMouseTech]

Drive a MT?

[1GrayBulldog]

Originally Posted by MightyMouseTech

And how do you reset it?

I followed the procedure that was posted up towards the top of this thread; turn ignition on (engine off, electrical on), press gas pedal down all the way and hold for at least 20 seconds. Remove foot from gas pedal and then just start the car normally. Very simple procedure and for me, the result was surprisingly effective.

[patricksr]

Thanks for all the great suggestions folks! I tried the throttle reset and I do not believe it did much if anything. I guess I have to conclude from the discussion above that it probably is a DCT issue more than turbo lag and something I have to get use to. As someone said above...DCTs are great for fast shifts at speed but not so great starting from a stop. Next time I am at the stealership I will see if I have the latest software...I believe my car was manufactured 11/2012.

[3002 tii]

Easiest way to resolve this is a huge gtg for 2011-2013 models, 6mt, DCT, and those with 'is' models or ppk's and do a comparison =)

[jester17]

Originally Posted by 1GrayBulldog

I followed the procedure that was posted up towards the top of this thread; turn ignition on (engine off, electrical on), press gas pedal down all the way and hold for at least 20 seconds. Remove foot from gas pedal and then just start the car normally. Very simple procedure and for me, the result was surprisingly effective.

Wow... really? Forgive the possibly stupid question, but this doesn't flood the engine somehow? Anyone care to chime in here on the workability of the power-on, throttle-floored-for-20-sec.-solution?

Cheers!

JBW

[aerobod]

Originally Posted by jester17

Wow... really? Forgive the possibly stupid question, but this doesn't flood the engine somehow? Anyone care to chime in here on the workability of the power-on, throttle-floored-for-20-sec.-solution?

Cheers!

JBW

There is no risk of flooding with a modern ECU controlled engine with this procedure, in fact I don't think you could flood any fuel injected engine doing this, it is only a risk with a carbureted engine.

[jester17]

OK -- so do I mash the power button once only, or twice, so the full power is on, but the ignition is not?

[daflamme]

Uh if you press it two time you're gonna turn it on and off again, no? You just don't press the brake padal so you don't sart the engine I think

[jester17]

2011 135i:

-- Press Start Button once: Transmission Selection Lights; Radio
-- Press Start Button twice: 'Service Engine Soon' light, ding sound
-- Press Start Button third time: Back to #1
-- Press Start Button fourth time: power cuts off

[2012_135i]

Originally Posted by Simsims

...this doesn't always make a difference - all depend on your driving habit as the throttle adapts to your driving habit after a few stops and goes.

I've noticed this as well. Most of the time I'm in Honolulu traffic just doggin' it along with everyone else and when I try to punch it the results are often disappointing. But if I drive it aggressively for a while it turns into a different car.

[2012_135i]

Originally Posted by patricksr

...I guess I have to conclude from the discussion above that it probably is a DCT issue more than turbo lag and something I have to get use to. As someone said above...DCTs are great for fast shifts at speed but not so great starting from a stop.

The very reason I didn't get the DCT is because of my experience with our Audi A3 which also has a DCT. Often herky jerky off the line, too much hesitation trying to make up it's mind, and outright confusion when in traffic jockeying for position. Pisses me off no end. I hate that transmission and didn't want to risk anything similar in the 135i.

[gmartan]

Originally Posted by Dackelone

BMW has been rolling out a detune for the 135i's. Mostly because people have been complaining(ie lemon-ing) the cars for noisy wastegate, injector and stalling or poor idle. The only way to get your old rip roaring throttle response back is to opt for BMW's PPK2 sw flash. The Performance Power Kit. Or.. go aftermarket and get a tune. Some say the piggy back tunes work, but I would go with a real flash tune (like Giac, Cobb, Dinan, etc).

I did the PPK1 (same as PPK2 without the hardware) and it immediately fixed the throttle lag. One year later the lag returned. The dealer says the PPK is still in place but it seems that the lag is back to stay.

[2012_135i]

Originally Posted by gmartan

I did the PPK1 (same as PPK2 without the hardware) and it immediately fixed the throttle lag. One year later the lag returned. The dealer says the PPK is still in place but it seems that the lag is back to stay.

Do you have any other info on this? Was the car serviced in between doing the PPK1 and when the throttle changed back to how it was? I'd be very curious to know how the car could do this to itself. Did BMW provide any kind of explanation?

[gmartan]

Originally Posted by 2012_135i

Do you have any other info on this? Was the car serviced in between doing the PPK1 and when the throttle changed back to how it was? I'd be very curious to know how the car could do this to itself. Did BMW provide any kind of explanation?

BMW denies that this problem exists even though throttle lag has a long history in most of their cars. Google it. It is not the lag that annoys me so much as the inability to predict it. It can get scary at times when you really need to move now! As stated by others, sport mode helps as does preloading the tranny slightly when moving away from a full stop but take your foot off the gas for a moment and you will wait to get power back even if you are rolling and no gears are changed.

I'm pretty sure they did a software retrofit and that the PPK code simply no longer works properly with the new flash. I'd be curious to hear from someone who did a non-BMW flash and resolved this problem. If anyone has a DCT car that has no delay ever from a stop or when trying to power out of a corner don't let BMW mess with it.

I still love to drive the car particularly in traffic when the turbos are spooled up. Delay there is minimal so it's good fun. If they could just fix this throttle lag thing....

[2012_135i]

Originally Posted by gmartan

...I'm pretty sure they did a software retrofit and that the PPK code simply no longer works properly with the new flash.....

That's what I would suspect as well. From what I've read on this forum, many people who get BMW PPK or other flash tunes refuse any software upgrades BMW service might want to do after their tunes to avoid that problem.

[No Style 135is]

I got 135is with DCT and I feel the throttle lag too even I did reset the throttle.

[shah269]

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

[patricksr]

Excellent point...I should have changed the title of this thread to DCT lag not turbo lag...my bad.

[BZAP///]

I have a 6MT and just had the SW update and no throttle response, quiet exhaust note. Very disappointed. Have there been any updates on this recently? I have a 2011 with 41K and this just happened.

[msf]

I turned off DSC and was amazed by how much power was being cut to the power train when this is on. Just push once to turn off DSC. Push and hold three seconds to turn off DTC. I am leaving DTC on and just turning off DSC. It is like a different car on drive offs. I think DSC is designed to keep you from getting into trouble by cutting power immediately to stop tire spin on fast drive offs and DTC is there to try to keep you from wrecking. Turning off DSC tones this system down quite a bit and makes the car much more fun to drive for fast drive offs. I use sport mode as well. Zero lag with mine.

Originally Posted by patricksr

Hi Everyone

I have had my 135is with DCT since April and the turbo lag (slight hesitation) at take off from a traffic light or stop sign is driving me crazy. It is better if I press the Sport button and even better if I drive it in S or M but in D it is maddening. I have read that a JB4 tune will eliminate this...is this true? Any other ideas?

Thanks in advance.

[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.