hi there, has anyone experienced a perceived slipping in 3rd gear when accelerating?

Best way to describe it is if driving up a slight incline, in 3rd gear, then accelerate medium pressure on the pedal, the revs drop around 800rpm then begin to rise again then quickly shifts into 4th. all the while the speed has been increasing at the same linear-ish rate, no hesitation in the acceleration.

I have been informed by the dealer that they think this is normal for this model. Its crazy annoying as when you are driving around and then plant the accelerator the revs seem to do their own thing and it takes a while for the car to get going.

I suspect worn clutch pack or maybe related to the valve body everyone seems to be talking about, she has 95K on the clock.

Any help would be great. thanks guys.

 

Its the valvebody

 

Normal? You need a new dealer! How many miles are on the car?

 

Update from dealer, they tested another vehicle with 60000km on the clock and they said exactly the same symptoms, obviously the car just has the same problem in my mind, i could be wrong not being an expert in these vehicles.
So they are officially stating that the slip is from the gearbox deciding that there isn't sufficient torque available when going up the hill and instead of changing down it is slipping the gear, bear in mind this only happens in 3rd. Most exaggerated going up incline but also present when accelerating medium to high in third. I don't get this at all when I disable PSM, or switch to manual mode. In fact PSM mode off is so good I might just stay there.

Is there any way to prove this is a gearbox issue, some kind of monitoring or dyno run. Have you had this problem, please could someone run this simple test, just look for a steepish uphill and as it changes to third apply a bit more throttle and keep it there, then just check your revs and see if they rise then fall then rise again before 4th.

Or anyone in JHB or pretoria that we can compare with.

I would think if its the valve body then it should also happen when in manual mode, but perhaps the software is locking the clutch.

thanks for the replies so far.

 

Just to give a point of reference my 2005 Cayenne Turbo with 54k miles does not slip at all in any gear. Just because the dealer tested another vehicle and it displays the same symptoms doesn't mean it's normal. The early (03-04) Cayenne Turbo's are prone to the symptoms you are talking about and a new updated valve body fixed the problem. However, I thought this problem was taken care of by Aisin (transmission supplier) in the later model years. Are you sure the car is not low on fluid? Low fluid will also cause the transmission to slip but its usually in all the gears. Hope you get it figured out.

 

Thanks for the reply, yeah the dealer just did a complete fluid change and changed the control unit, when I took it back the second time they added another litre to the transmission, so I assume its filled.

 

I don't have any slippage but I have noticed that taking certain corners it's almost like it can't make up it's mind whether to downshift to 2nd or not and for whatever reason there seems to be some sort of lag. It happens regularly on one corner that I take almost daily on my way to work. Just an average city street corner taken at ~20mph or so.


Mine does not present so much as a slip though as less-than-enthusiastically-responding throttle. If that makes any sense. It's like I keep giving it more gas but it's not made up it's mind yet to listen to me? Hard to explain.


Mine is an '05 CTT with the valve body already done. At least in my case the valve body was easy to diagnose. Get up to about 50mph in 5th gear and floor it. You will know INSTANTLY if your valve body is failing. About gave me a heart attack the first time it happened. I thought something broke or I hit something it was that hard a slam.

 

I don't really like the transmission behavior of my '09 CTTS in anything BUT Sport mode - the 2nd gear start, the slower downshiift when accelerating and it's pristine with under 30,000 miles, so doubt it actually has any issues. Would using Sport mode circumvent the issue for you?

First thing I do when I get it and start it up is press the sport button, then the normal suspension setting, then hit the toggle for normal ride height. This gives me the 1st gear start from a stop, better shifting, and a comfortable ride, which is what I consider the best combination. On really bad roads, I'll sometimes select the Comfort suspension setting too. As part of my widebody project, I'm going to need new wheels (different width and offset) and will probably go down to 20s, which will give me a bit more sidewall for better ride and signficantly more tire choices.

 

I actually haven't had the car long enough to detect what you're describing, which means either mine doesn't do it, I haven't noticed it, or Sport mode prevents it from happening, which is how I drive the car most frequently. I could go test it for you, but the car is already at the body shop getting ready for installation of the widebody kit and repaint. Also, never understood why people buy and insall the Sprint Booster. From what I gather, it's really just sending a greater signal to the DME for less throttle plate angle (like you're pressing the pedal further). If that's installed, I'd remove it and see if it eliminates the problem as maybe there's a relationship in the Porsche software between actual throttle plate angle and how the transmission operates and the Sprint Booster is throwing off that relationship - no idea, just guessing since you mentioned that was installed.

Also, I've read good things about the Continental DWS tires (Dry, Wet, Snow) for all-season use including winter, but I'm sure your full Blizzaks will be even better if you can do a winter wheel/tire swap, which it now sounds like you have ready. Continental makes a different tire called a DW too, so make sure you get the DWS if you're looking for a single set for year-round performance.

 

Mine is slightly worse now, also happening in sport mode. The best test is drive on an incline in 3rd gear then push throttle hard but not enough to change and watch the revs, they climb then drop, then climb again before shifting to 4th. CRAZY annoying if you are used to manual gearboxes. Ruins the feel of the car.
I haven't been able to find a local car to verify if this is normal, the dealer assures me its a design feature, and will give it to me in writing. I disagree but can't prove that its not normal as yet. I have found numerous technical articles detailing fixes.

http://www.sonnax.com/articles/137-a...body-diagnosis. (Slip on 3-4)

http://www.transgo.com/products.php?...product_id=257.

http://www.sonnax.com/parts/1866-loc...trol-valve-kit. (General info on right panel)

I would try one of these solutions but my car is still on maintenance plan so don't want to void any warranty at the mo. I have asked for the written confirmation from Porsche headquarters but nothing as yet.

Unfortunately I am immigrating to Vancouver at the end of the year so I will be selling her soon, and not sure if I will have resolved this issue before then, will keep you posted though.

 

Interesting, my father in law has an 06 CS,the dealer as well as the Indys refused to change the tranny fluid.
The Indy claims is that would cause slippage, dealer flat our refused the work.

In your case new fluid and CU corrected slippage or perceived slippage?
I have an issue with transmission service at 16 years or 160K. Is the tranny filled with unicorn blood.

A sore subject for me as the tranny on my 958 CTT went out at 127K to the tune of $11K.

 

I just did the transmission fluid and filter the other day on mine. It’s not as simple as an oil change but not too difficult either.

 

My 09 ctts exhibits the exact same behavior.

 

My 2013 Cayenne Turbo has this exact same slipping in 3rd gear. It's CPO so I brought it to the dealer but they didn't know what's causing it.

Some torque converters have a feature where they "lock up," meaning a clutch engages and it locks the engine to the transmission input shaft, providing a direct 1:1 drive ratio. Does the Cayenne have this? It's possible that the slip we experience is the torque converter switching from a fluid coupling to a clutch engagement.

 

You can try having the adaptations reset but most of not all the problem is in the logic for the tcu. Unfortunately the priority for the tcu is economy and comfort. Hence the difference between psm on and off. This tcu tries to be smarter than the operator and "psychic" to a degree to anticipate the operators intentions. We all can understand the theory of this however the logic is only as good as the programmer. Apparently it's not good enough. A 100% functioning valve body has to be ruled out first. The second part is reasonable owners manual and learning how to drive it to make it do what you want. This transmission gets confused no doubt.