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Discussion Starter #1
I am new to Audi and new to this Forum. I have been driving my 2016 Q3 Prestige/Quattro since July. I have been experiencing loss of power every few days. It only happens when I accelerate from a full stop while the engine is warm. It feels like I removed my foot from the accelerator (Which I didn't.) The dealer has been unable to duplicate the issue and no fault codes were found. Am I the only one experiencing this? Thanks for listening!
 

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Discussion Starter #3
Yes. It only happens when I first press the accelerator. It lasts for a second or two, then drives normally. It does fine at high speeds.
 

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This does sound like turbo lag, though really pronounced lag. Are you using 93 octane fuel, out of curiosity?
 

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Discussion Starter #5
What exactly is turbo lag? The dealer never mentioned turbo lag when I took it in for service. I only use 93 octane fuel. I return for service soon and will mention turbo lag at that time.
 

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From Wikipedia:

Turbocharger lag (turbo lag) is the time required to change power output in response to a throttle change, noticed as a hesitation or slowed throttle response when accelerating as compared to a naturally aspirated engine. This is due to the time needed for the exhaust system and turbocharger to generate the required boost. Inertia, friction, and compressor load are the primary contributors to turbocharger lag.
 

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The BMW twin scroll turbo design has pretty much eliminated the turbo lag but I'm unfamiliar with the Audi turbo design. I do know that with the SprintBooster installed I have not experienced any significant type of throttle lag.
 

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It happened to me for a few thousand miles also.

The dealer never pinpointed the issue as no error codes on the computer analysis. It eventually went away.

I've read about the same issue on other audi forums for other type of audis (I believe audiworld.com)
 

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Does the turbo lag stay until the car has had time to learn your driving habits? Sounds odd that it just goes away by itself.
 

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Turbo lag is a physical function of the engine design and is inherent. It does NOT go away magically after some period of time or mileage. If you experience another similar characteristic that DOES go away after some time or mileage, then it is/was DEFINITELY NOT turbo lag. Designers and manufacturers work hard to balance turbo lag with the acceptable driveability that it brings (or not). It becomes a matter of cost versus gain in making good power, achieving good fuel economy and then providing good driveability. Turbo lag has been around since turbos were first used to improve internal combustion efficiency. There are many incremental techniques used to reduce its negative effects whilst maintaining better power from smaller displacement engines and managing good - acceptable, driveability.

Driveability btw, includes the comparative feel of the turbocharged engine with one that isn't, along with the gains in power and fuel economy. Turbo lag is by definition an almost necessary fault of even having a turbocharger. Sequential smaller turbos can reduce this effect to almost imperceptible, but do NOT even imagine it's not there. It is. About the only way to completely eliminate it is to physically decouple the turbocharger from the exhaust that drives it.

Think about it this way : the turbocharger must first receive exhaust to spin, THEN it can provide compression or boost of inlet mixture to the engine. The exhaust gas has to have been first taken in, so lag is the time it takes for the first inlet air to be combusted, before it can then be sent to the turbocharger to then compress second new air to gain power (and feel of acceleration). This just cannot be avoided - except by :

...an Audi innovation now under development, that's uses not exhaust gases, but electric motors to spin the compressors before they can be turbochargers. The first charge of air is compressed by electricity, then when it becomes exhaust, it can then spin the turbocharger becoming a better efficient design (than the electric motor) while at the same time COMPLETELY eliminating turbo lag, cuz the electric motors are always at the ready to provide boost when there isn't enough exhaust first.

The prototype works great - 600 hp out of a 2.5 liter 5 cylinder (yes the very same derivative from the Ur Quattro, and later TTRS and RSQ3) this car is now in development and has proven to hold improved rotational dynamics that allow it to spool up to full power MUCH faster than a sequentially turbocharged same displacement engine (with the same peak power). That means quicker acceleration in time to distance metrics - all while improving fuel efficiency (and of course fuel economy too)...
 

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NOTE: My problem was NOT, TURBO LAG, I've had turbo cars for a while now, so i know it was not that. I just don't know what it was, I just know it went by its own.
 

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I am having a similar loss of power on my 2015 Q3, only I lose power at times when I am moving slowly, like when I am almost stopped, but then press on the accelerator. It feels as though the car shuts off for a few seconds, then it goes. Very scary as it always seems to happen when I am pulling out into traffic. The dealer had no resolution for this and of course it didn't do it when they had the car
 

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Discussion Starter #14
This describes my issue perfectly! In November 2015, I finally got the Audi of America tech team to test drive my car. After about an hour, they said it was what they call "NYC Foot." If you go from the accelerator to the brake, or vice versa, in under 0.3 seconds, a device will cut the (fuel) power. This was added to vehicles due to a lawsuit back in the 1990's when some motorist claimed that the car was too fast and could be used for racing.
I have had many near disasters when I have tried to accelerate in order to avoid an accident! I have been trying to get Audi of America to put all of this in writing for some time now, but it still hasn't happened. This is why I have waited so long to update my post.
I am trading in my Audi next month for a Subaru Forester. I will NEVER purchase an Audi again! I am considering suing Audi to try and recoup some of the money I am losing when I trade my car in. I will keep all updated. Take care.
 

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This describes my issue perfectly! In November 2015, I finally got the Audi of America tech team to test drive my car. After about an hour, they said it was what they call "NYC Foot." If you go from the accelerator to the brake, or vice versa, in under 0.3 seconds, a device will cut the (fuel) power. This was added to vehicles due to a lawsuit back in the 1990's when some motorist claimed that the car was too fast and could be used for racing.
I have had many near disasters when I have tried to accelerate in order to avoid an accident! I have been trying to get Audi of America to put all of this in writing for some time now, but it still hasn't happened. This is why I have waited so long to update my post.
I am trading in my Audi next month for a Subaru Forester. I will NEVER purchase an Audi again! I am considering suing Audi to try and recoup some of the money I am losing when I trade my car in. I will keep all updated. Take care.
I am sorry to hear of this issue for your car and yourself - especially to drive you away from Audi as a current and future customer. In fact I am SO bothered by this I would ask you to PM me with the names of the so-called AoA tech team that diagnosed your problem and cause via "NYC Foot." This sounds so bizarre to me that I will elevate it myself within AoA to see what they mean and intend to do about losing customers over it...

Thanks -
 

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I HAVE to post this comment as the CURRENT observation of this apparent condition.

1) I can find NO such similar reference to this condition in any documents at AoA as of this date.

2) NONE of the 6 Techs and AoA area techs that I SPOKE to about this condition called "NYC Foot" OR the programmed/coded brake-throttle response within 0.3 sec have even heard of such a thing NOR would they think that such a thing exists.

3) The OP has NOT responded further to me or this forum about the issue, so I could corroborate (as I would be SO anxious to do) the condition OBJECTIVELY and seek AoA resolution if need be.

4) The threat of legal action IS serious, and I take it as so - BUT at the same time, idle or passive conjecture about it (legal action) is negative and incitement (for another agenda) for which has NO place on this forum imho...

I am TRULY sorry that the OP has had an issue with his Q3 for which it seems he had to leave the Audi brand to resolve and post here about it. There seem to be others having a similar issue or at least the perception of one. I WANT to find solutions and make ALL of us happy Audi owners, but can only deal with facts - objective and documented. So far to THIS ISSUE, I do NOT have either.

We DO know that when you take your foot off the throttle, fuel within a system pressured to some 1500 Bar or 22000 psi is shut down to an idle amount electronically, and as soon as you step back on the throttle, that system restarts again. At just 75 psi, a modern electronic fuel injector requires about 1.5 ms to open - to suggest that there's a program or code that intercedes a 0.3 sec delay for some reason from the 90s about a car that 'was too fast', needs better well, reasoning...

I DO want to keep this forum informed and will try my best to contribute real and effective actions towards it. For now that means THIS post.
 
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Update : just FYI, I DO have some details from the OP and will pursue them to the extent I can either corroborate or resolve and both reply to the OP and this forum for all to know what's going on with this...

Stay tuned -
 

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Update : just FYI, I DO have some details from the OP and will pursue them to the extent I can either corroborate or resolve and both reply to the OP and this forum for all to know what's going on with this...

Stay tuned -
Looking forward to seeing an update. :D
 

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OK - I DO have some additional data to share. I talked with my AoA area Technical Field Manager and while he has NOT heard of "NYC foot", he IS aware of a NHTSA/DOT required code for brake-accelerator delay/cutoff that ALL cars sold in the USA now must comply with. There is a secondary switch (BEFORE the brake lights engage) that can sense brake pedal pressure and WILL cut-out the accelerator electronics for between 2-4 sec, depending upon a variety of other metrics being recorded.

He also added that for ANYONE to likely engage this cut-out they MUST be driving with what is known as a two-foot driving technique that uses the left foot constantly riding the brake, while using the right foot for the accelerator. He has tried to engage this lock-out with normal single foot driving techniques and cannot do it. He did NOT know the sequential delay but promised to find the data and inform me. btw, ALL Audis have had this feature since at least 2015.

This MUST account for what the OP and perhaps a few others have experienced. Since I am NOT a two-foot driver (as my other cars have a clutch), I cannot even IMAGINE riding the brake with my left foot, but maybe this is what "NYC foot" is...

In any event IF this is a requirement of NHSTA/DOT - (essentially btw, NOT because of some lawsuits about cars going too fast, but rather the much more recent Toyota unintended acceleration issues), then every car with electronic throttle by wire will likely have a similar issue if one can engage it. If as the OP states, he has - now had, this in his Q3, I wonder if his current Subaru has an e-throttle and can he possibly 'beat' its cut-out coding also. I'm also curious if indeed he uses a two-foot driving technique and is that known as "NYC foot.'

While I have tried (in vain) to engage this phenomena with my Q3 (using my normal one foot driving technique), I WILL soon try the two-foot driving technique and report on my ability to engage/discover this issue. I SINCERELY appreciate the OP reaching out to me and bringing this important issue to us and I am now VERY interested in how it spans our driving experiences.

Stay tuned some more -
 
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Discussion Starter #20
Thank you so much for taking the time to obtain this information! I do NOT use a two-foot driving technique. The Audi tech person who test drove my car last November, did NOT use a two-foot driving technique to duplicate my concern. It occurred when he went from the brake to accelerator, or vice versa, in under 0.3 seconds. He called it NYC Foot for this reason, stating that drivers in high stress driving situations may do this. I have recently heard of a similar complaint from owners of the 2016 Jeep Cherokee. I wonder if my vehicle's brake-accelerator delay/cutoff needs some sort of calibration, or is defective? I tried changing my driving habits after 42 years, but the condition seems to be more frequent.
I will take delivery of my new Subaru next week, and because of the information you provided, will now test drive before I finalize the sale. I will keep all updated.
Thanks again.

Frank
 
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