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Cayenne Gearbox issues, is a valve body the solution?

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cayenne turbo gearbox harsh shift shifting issues valve body
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16K views 14 replies 9 participants last post by  lradkov  
#1 ·
I recently purchased a high-mileage (190,000) 2004 Cayenne Turbo which has a gearbox issue. The symptoms it shows occur once the transmission fluid has had some time to warm up, after which point it starts having very hard shifts, particularly from 2nd to 3rd where the gearbox seems to disengage and the revs rise before a massive bang when it finally shifts to third. After this happening a couple of times the gearbox locks itself into 5th and you can't shift into any other gear. The only way to solve this is by turning the engine off and then starting it again, then the gearbox will select other gears. Also, it never seems to engage 1st and always starts in 2nd.

The reputation of these first-gen Cayennes and Aisin-Warner gearboxes in general seems to point directly to the valve body being at fault, however I'm just wondering if it's potentially more than that and if the entire gearbox should be replaced?

Having researched this issue a bit, it seems that there are two different valve bodies that were used in these cars, one with a pressure switch and one without. Is there any way to tell which mine is by the VIN without having to pull off the transmission pan and check manually?

Finally, if a valve body is indeed what I need, whereabouts can you find quality remanufactured or new units? I'm not interested in the many Chinese copies sold on eBay, I'd like to know I'm fitting a quality part that will last.
 
#4 ·
Sounds like the valve body. Individual solenoids can be sourced if you're really into DIY. I'd suggest starting with a dealer see what they get for the entire valve body, then do a Google search with the valve body part-number. There are a number of sources that I've heard are reputable, but having no experience with them I'm hesitant to list them (and I've forgotten who they were..)

BTW - it's supposed to start in 2nd - especially when cold - it helps in heating up the catalytic converters. I seem to recall pressing the PSM button will allow it to start off in 1st gear, but it's a very short first gear and it will be upshifting in seconds.
 
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#6 ·
I had a similar problem of the gearbox disengaging after i changed the Tranny fluid. Put a rebuilt valve body in and all work fine. I have had hard shift problems after this. Mostly hard downshifts from 3rd to 2nd. After chancing the issue for a long time I came to a few conclusions 1) make sure the engine running smoothly (injectors, Knock sensor, MAF, etc) and the battery is good. A poor battery can cause lots of problems with these vehicles.
 
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#9 · (Edited)
I have hunch that performing multiple transmission flush and fill up with Porsche approved transmission fluid will make your stick very smooth and hardness will be gone.

Once flush and fill up is done, reset the car’s computer/DME/ECM by pulling both battery cables and touching them together for 20 seconds and put back on battery. So that all sensors mounted in various part of gear box, fluid reservoirs can read that new data that fluid is new with no shavings of metal or buildups in it and send this new data/input to car’s computer/DME/ECM and computer can turn off lights in instrument cluster related to this trouble or DTC.
 
#10 ·
Cayenne S V8 4.5 US said:
I have hunch that performing multiple transmission flush and fill up with Porsche approved transmission fluid will make your stick very smooth and hardness will be gone.

Once flush and fill up is done, reset the car’s computer/DME/ECM by pulling both battery cables and touching them together for 20 seconds and put back on battery. So that all sensors mounted in various part of gear box, fluid reservoirs can read that new data that fluid is new with no shavings of metal or buildups in it and send this new data/input to car’s computer/DME/ECM and computer can turn off lights in instrument cluster related to this trouble or DTC.
Click to expand...
That's more along the lines of probably worth trying - except the fluid IS expensive - but that year had known valve body issues with sticky solenoids. They can be replaced - which is a fairly skilled labor sort of job, or the entire valve body can be replaced.

Of course all of this is useless discussion since he hasn't been here in over 6 months..
 
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#14 ·
The really troublesome transmission years were from introduction until sometime in 2005 - after that the transmissions were pretty reliable provided they received some level of maintenance. Question - have you tried doing a transmission oil change? Sometimes that's all that's needed to free up a balky solenoid valve (which would account for the symptoms you've experienced.)
 
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#15 ·
I have similar issue on my 06 Touareg V8. Sometimes, especially after hwy drive, it doesn’t engage 5th gear. I have to restart the car and everything works fine until the next time it happens…

I have replaced the vavle body with brand new one from VW and it didn’t fix the issue. I brought the transmission for a rebuild at a questionable transmission shop and they didn’t fix it. They installed transgo valve body rebuid kit along with whatever they claimed they did…
I replaced the 8 and 14 pin harnesses which were causing at oil leak at the connectors. Also traced that the oil leak which wicked all the way to the transmission controller underneath the front passenger seat. Cleaned everything with QD contact cleaner. Still have the issue…
Measured all solenoids resistance by ATSG.
I have done multiple logs with VCDS, monitoring all transmission values (solenoids, torque converter clutch etc) and couldn’t find anything unusual.

That is the ATSG manual for this transmission for any reference
 

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