Our new to us 2005 Cayenne S has an intermittent problem /quirk. The vehicle is in amazing condition with 100,000 miles on it , we purchased it in February of 2018 and it has performed flawlessly until recently and now has developed a intermittent problem. It starts right up and idles fine but of late after starting it up and beginning to drive the vehicle it seems a bit sluggish at first then when you come to a stop it will sometimes start to idle a little lower and vibrate and it almost feels like it will die. Then as you start to accelerate from the stop it will run fine then if you stop again it might do the same or not! then after this happens it runs fine? It has set no codes and has never completely died but it can be a bit discerning. It seems only to do this at a full stop then as you apply a bit of throttle it accelerates just fine.
At freeway speeds it is fine at city speeds it is also fine and after it does its sputter for lack of a better word it is fine. I am at a loss as to what it might be.

Any help would be appreciated

 

 

Are you sure it is the engine? Could it be the transmission switching?

I believe my 2004 S is working just as it should, but the first few times it did the following, I thought it was malfunctioning:

On a cold start, it starts up fine, back out of driveway, then when driving 50 yards or so until the first stop sign, it feels really sluggish, as if I'm dragging something. After that it is fine. Turns out that's exactly what is supposed to happen. But instead of actually dragging something, it shifts into first gear. Only when stone cold on the very first drive of the day. After that (for example, when starting out from that very first stop sign), it basically never ever goes into first unless I were to manually shift it there.

Really weird, but as I now understand, it is perfectly normal.

 

Taking off in 1st gear is anything but sluggish. Yes, it's supposed to when cold and I'm very careful with the accelerator...little too much pedal and you get pinned to the seat.
Sluggish in 1st gear means something is wrong. It's also supposed to take off automatically in 1st whenever the gas pedal is pressed down about 50% or more.

OP,
Sounds like you have cracked coil packs. Probably time to change them and the spark plugs.
Bad motor mounts (expensive) or torsion bar (cheap and easy) can also cause a vibration when coming to a stop. This is a vibration and NOT a drop in idle or lack of performance issue.

 

How does your damper look
955-375-101-13-M100

 

Thank you all for the quick replies, I will check for a vacuum leak but I get no indication of one when it sits in my driveway at idle, Not sure what the damper condition is I will have to check on that one as well. The last two vehicles I owned would throw a code when a coil pack was going bad , wouldn't this do the same ? I will check the condition visually of the coil packs and pull the plugs as well. I have noticed the vehicle starts off in 2nd gear unless I put it into 1st so that makes sense.I originally thought it might be the transmission ans was getting ready to find a reputable shop to service i, but then I read a couple of posts about the left side fuel pump going bad. I tried to test it by pulling out the right fuel pump fuse , then the left side fuel pump fuse to try to see if I had a dead fuel pump (with a 3/4 full tank ) but neither had any effect .

I again thank you all for your giving me some direction on what to look at

 

All 8 of mine were cracked in the exact same spots at 60K miles with no codes. They rarely throw codes unless really bad.
If it's been more than 40K miles, they're probably shot.

 

Awesome picture I will diffidently check all of the coil packs tomorrow .

Thank you again

 

Better to use ether than brake cleaner. Brake cleaner is too wet and can damage things it lands on, like aluminum components. Ether is more volatile so it dissipates much faster and will also have a more noticeable effect if sucked in through a leak than brake cleaner will.

OP, if none of the suggestions here ban out, you might need to take off the intake and clean the throttle body using MAF cleaner and a rag - both sides of the plate and all around the housing where the plate closes when at idle.

 

Thank you for your advice as well, I truly appreciate it.

 

Any resolution to this?

 

Well, I tried everything mentioned , cleaned the Mass airflow sensor, the throttle body, replaced plugs and coil packs and did the tbs reset . it seemed better then returned.
Now its wild fire season and I haven't been home much to drive it. My the wife says its still occurring. I asked her if it went away when she released the brake and she seems to think it does. So I'm thinking it might have to do with the vacuum booster for the brakes. I haven't been able to get home long enough to try to tack it down.