jyang7788

Hey guys,

Unfortunately, I've recently developed a bit of an issue with hesitation when passing. For example, I'll be driving steadily at 45, but when i go to accelerate to pass, the engine does not respond immediately, but rather would jump from 1500rpm to 2750rpm or so after a second or two then accelerate normally. It feels like the car is changing gears but it is not.

Any idea what could be causing this? My initial thought was to reset the transmission adaptation/ throttle adaptation, but could this also be a symptom of needing a carbon cleaning?

Car has 73k miles.

Thanks in advance!

jyang7788

Also, would add that it doesn't exhibit this behavior when in tiptronic mode.

KevinGary

Model year, engine, Quattro?

jyang7788

Its a 2006, 3.2 Quattro, thanks!

tarheelbandb

It could be a few things. It's possible that you need the throttle response to re-adapt.

"Put keys in ignition,hold gas pedal down,turn keys forward to standby/aux mode,hold pedal down for about 15 seconds, turn key back to initial setting, take foot off gas and leave everything for about two minutes"


Have you pulled any codes?
Are you shifting ok the est of the time?

jyang7788

Thanks for this. After re-adapting the throttle response, I feel like it definitely exhibits the hesitation/surge less often. However, it still happened a few times in my 30 minute drive.

Unfortunately I haven't had the chance to bring it over to my indy to scan for codes.

Usually car is very smooth, just at cruising speeds, 40 mph+. Almost feels like a kickdown.

kelisko

This sounds just normal to me. In order to accelerate suddenly, you need to downshift which explains why the RPM jumps from low to high. Everything depends on how you manipulate the gas pedal. If you are driving in D mode, don't expect the car to jump immediately. In S mode you wouldn't feel this one second hesitation. Acceleration in faster and better. In Tiptronic mode, things would be perfect because you control everything yourself.

jyang7788

I feel like the vehicle is not downshifting as the gear indicator in the center display does not show it doing so... RPM jump does resemble a downshift though, if not a bit smoother.

kelisko

I see. But even if the vehicle does not downshift when this happens, it still sounds normal as you press down the gas pedal further to accelerate, right? The vehicle will first try to accelerate with the current gear (RPM jumping) then will downshift if that gear is not giving enough torque to launch the car (RPM jumping higher). And all this based on how you press the gas pedal.

I have to admit that in D, sudden desired accelerations are sluggish, even with mine and you can hear the engine struggle to adapt at low RPMs. If you're speeding you rather use the Sport mode or the Tiptronic. Normal Driving mode does not do accelerations well in my opinion.

jyang7788

I agree, in my previous vehicles my RPMs would typically increase smoothly as I depress the gas pedal and as such, acceleration feels smooth and unrushed. If i depress further, the car's rpms will jump as it downshifts for additional power.

With my A6, the rpms remain relatively stable for a second or two under light to moderate acceleration and my speed hardly moves, then rpms jump 700-1k and i get moving briskly, although the indicator in the instrument panel does not show that the car downshifted.

Whats strange is that the car accelerates fine from a standstill, this strange behavior only happens when I'm cruising at 45+mph and attempt to accelerate from there.

Would also note that I can feel the torque converter engaging, so that appears to be functioning properly.