95_993

I am not sure if the Cayenne has individual pressure switches for each gear or if that's all handled by the trans module, but I had similar issues with our MDX and it was the trans pressure switch ($35 part) on 2nd-3rd that would cause the car to stutter at certain throttle settings as it reached the shift point of around 2500-3090rpm.

Have you tried clearing your adaptation settings to see if that changes anything as it learns new shift points?

19psi

I don't know if it disables it completely, but give it a try.
When my last set of tires were at the end of their life, my S had no issues with spinning tires on dry pavement causing the the traction control to kick in. A turbo should have no problem doing that.

cornic

Okay so I"m going to take idiot of the day award on the fourms, it's just the dang PSM (atleast I think so). *Shakes head* This car is new to me and while I of course have driven other cars with traction control I haven't driven this one and certainly not one with this much HP. Trust me I didn't want to come on here and say this is all it was but I figured it might help some other poor soul out some day haha. Turning off PSM and flooring this car brought it back to life and much of the stutter is gone seemingly.
Thanks for everyone's efforts.

Wisconsin Joe

It's always good to hear a problem solved.

Even better to hear that it didn't cost any extra to fix it.

cornic

I hate to have to bring this thread back to life, but here I am. So whatever is going on is most def not the PSM.

I have been feeling out the issue a bit more. I am going to try and describe it again. It's definitely related to the engine/ecu in someway I am certain now.

A quick story to help paint the picture. Long ago I owned a VW Jetta 1.8 T. I chipped it to get more boost. I got more boost and the car was significantly faster, however occasionally with the right throttle amount combined with the right amount load on the engine I could trip the car into limp mode, almost like it over boosted or boosted too quickly?

What I am feeling is similar to this here. If I slowly get into the throttle I get significantly more power up until about 3k rpm when full boost hits. If I keep the throttle at just the right spot it won't start shaking. If I go too far or not enough it will start to shudder and jolt. It's almost as if the tune on this car is just jacked up or the engine is loosing boost or overboosting. Does what I am describing make sense? There is a combination of load on the engine, boost, rpms and throttle that cause this to happen. For instance going down hill vs uphill I get totally different results. When this does happen I can tell the engine is throttling itself back significantly until such time I take my foot out of it and try again.

I am not getting at CEL and I know I am not engaging the traction control because the light for that isn't flashing either. I can almost always reproduce the issue but occasioanlly everything just seems to 'hit' right and I can tell it's totally different more powerful car. Any thoughts on how I should proceed? Is there anyway to tell if this thing has been tuned poorly by someone else perhaps?

https://www.ecstuning.com/b-assemble...60210420kt5kt/ . this close to just buying this and swapping these out.

Thanks again all!

davef

I'm having what sounds like the exact same issue with my 2004 Cayenne Turbo. No codes are being thrown but it is hesitating violently upon medium to hard acceleration. 3000 miles ago I changed the coils and plugs as well as the diverter valves. I had been getting misfires in a couple of cylinders. The car ran well for a while and just started doing this about a week ago. So far I've tested fuel pressure with both pumps running and then each pump individually. All good at about 57psi. It will hold that for almost 25 minutes after shut down. Any help would be appreciated!

cordsig79

Engine mounts that are worn out make it feel like a transmission has symptoms or issues and accelerations are choppy and harsh...

Harsh shifts can be due to low pressure from a slow leak around the valve body on the transmission too...…...getting a new remanufactured VB and gaskets with fresh fluids can solve that......you would never see a code for this.....but you would see spots where you park and see a red fluid.

davef

Turned out to be crappy non-Beru coils. I finally got misfire codes out of the truck. New Beru coils in and mine is sorted.

cornic

I swapped coils and pluggs on mine and it helped a lot now having other issues but just wanted to report in this case coils and plugs is definitely a good place to start. I also wanted to stay the CEL would flash 'sometimes' i never got a CEL code that stayed on in this case.

Dilberto

Flashing CEL at full WoT is clearly plugs/coils...