GlenC

2008 Cayenne S starts and runs fine. Fuel high pressure setpoint and actual values match. After driving 20 miles, shutdown and leave car for a while and when I return, car starts normal, idles for 5-10 seconds then gets rough and ultimately dies. HP fuel pressure drops from setpoint like being starved of fuel. Fuel pressure, key on engine off, about 5bar. Now history: 135K miles Cracked fuel filter - Replaced Engine would die at 1/2 tank.... bad LP fuel pump - Replaced Both VDO (138K) Then in a few hundred miles the problem mentioned above started happening every few hundred miles Replaced fuel pressure regulator - problem happened again Replaced High Pressure Fuel pump and Sensor Problem still exists ....

Interesting read.. I am having a problem with my 2008 Cayenne S Had a fuel filter crack and leak, so replaced that. About 3000mi later started having fuel pump problems (at 1/2 tank it would shutdown while driving) Ultimately when it shut down, I could pull a pump fuse and it would run on one, not the other. With 137K miles, I replaced both pumps. Everything seemed fine. A few hundred miles later, I drove the car 20 miles to a friends house. A couple hours later, we went to leave, started normally, but in about 5-10 seconds, started running very rough and shut down. 3-4 restarts the same. About 4-5 hours later, I went to leave, thinking I'll need to call AAA, however it started and ran normally. It was normal for the next few months and few hundred miles. Now about 200 miles later, the problem has become very frequent. I did manage to get it to run, started driving home, however noticed it would falter if I tried to accelerate ...... drove 20 mi home no issues driving easy. Today, checked Durametric and code 1025 was there. Started and ran, HP setpoint = 40, HP actual was about 36-44. Graph of actual value was like a wavy saw blade.... 1 mb fluctuations in the values as values went above and below the setpoint. Cleared code 1025 and it returned. The Fuel high-pressure adaptation values 1-5 range from 0.9 to 1.25 Fuel high-pressure adaptation range 1 = 1.0 Went back out to drive car with Durametric running. Cleared the 1025 and CEL went out. The fuel HP values seem to closely follow the setpoint. This time there was no faltering while accelerating, everything seems normal. The difficult part is this may act normal for >100 miles or <20 miles, I won't know until it happens. Anyone with the Durametric, How smooth is your actual HP Fuel value and how much fluctuation compared to Setpoint? Unfortunately, I have a family trip planned, towing the Airstream, in 8 days.... I need to find the problem. At this point, I'm leaning towards replacing the HPFP....

I'm looking for the wiring diagram for the Cayenne Turbo seats. Since my back does well in my '14 Cayman S and '08 Cayenne S seats, I purchased a pair of used '16 Cayenne Turbo seats to put in my '75 GMC Motorhome I am restoring and would like the wiring diagram to utilize seat functions other than just power and ground..... I will not be connecting the air bags. Thanks

Just had to replace mine, '08 CayenneS. It developed a crack and started to leak after 134K

It's been so long ago, I forgot I even did this.... As I recall, I had to take off passenger side air flow sensor and the intake pipe, the loosen the belt then a very tight space to get at the sensor. Sorry I don't remember more.

Thank you for the idea, it got me out of a bind and was $0 ...... Car was in at my local dealer last week and they saw the fix.... they were surprised when they saw it, but agreed it was better than spending $2k or so for the shaft replacement.... I have over 8K on the fix and sort of forgot about it....

My 08S with 108k gave me the sudden banging Wednesday during acceleration... thought I ran over something, til it happened again.... Searching the internet.... driveshaft support! Put it into Special Terrain Mode and crawled under to check, yep, shaft loose.... Normal driving and there is no sign of anything being wrong, drove 50 miles home on Fwy before starting repairs.... I'm starting to think my trips to Yosemite are cursed!!! Last year, 1st trip, a coil pack failed (second one) about a half hour out of Fresno on a Saturday morning..... found a replacement and was back on road later that afternoon... (after I got home, replaced remaining 6 coils). A couple month later, back to Yosemite.... leaving the park the first night, the melting snow and darkness hid a big pot-hole.... sudden blowout! (ultimately new control arms and 2 new tires).... The next day, cones in place.... 5 cars had blowouts while I was changing my tire that night! Planned a trip to Yosemite next week and Drive Shaft Support failure.... Fortunately I replaced the Thermostat, Water Pump and repaired the loose tubes in thermostat housing last month. Since I'm limited on time, I decided to go with the hose repair method. Can't really see any reason this won't last for a long time. This shows the rubber support failure: This is where I cut off the rubber support from bearing and housing, leaving the rubber that was attached to the bearing and housing. I had some 3/8" air hose that was just about the right size. I cut pieces 1" (25mm) long and tied together with SS Safety Wire. I think I actually used a total of 13. I tied them around the bearing first, then slipped the housing on at the top first, then used a screwdriver to compress each piece of hose at the bottom to fit into the housing. Once I got the housing in place, I used safety wire to hold the hoses into the housing. I figured the safety wire was a longer lasting product than cable ties. The fix works, no noise, no vibration on hard acceleration.....

I just discovered that my failure in the thermostat might not be the thermostat but the wiper seal that's inside the thermostat housing. Information on some of the other forums got me to looking inside the thermostat housing and after a trip to the dealer looking at a new housing there is in fact a seal or wiper pressed into the thermostat housing that seals against the sleeve on the thermostat. The lip of the seal is totally gone on my housing and if I put in a new thermostat I would come up with the same problem again. Now it's time to find a replacement seal I'm going to try and find a PTFE wiper seal Sent from my SM-G920V using Tapatalk

Next step is to replace the O-rings on the coolant pipe in the rear of the Thermostat housing

Finished installing pipes in thermostat housing.... One pipe installed and epoxy spread on inside of housing for second pipe... I used the radiator hoses to hold the pipes in the proper position while the epoxy cures. Spread epoxy on pipe before installation... Both pipes installed I'm quite happy with the results..... and saved $300++ Glen

Yesterday I got the pipes & housing cleaned and ready to install pipes....

Guess I'm going to epoxy the pipes back in, both were loose..... Glen Sent from my SM-G920V using Tapatalk

Great help! Thanks! Got into my '08S and found the pipe loose on the thermostat housing.... guess I'll try cleaning and using epoxy to reinstall.... the epoxy I use for golf clubs seems to work fairly well.... Sent from my SM-G920V using Tapatalk

Problem fixed!!! YEA!... Turned out to be the pressure sending unit... Once I reinstalled the working Durametric, I did a road test while monitoring Oil Temp, Oil Pressure and Oil Pressure sender voltages. All was normal until the oil temp rose above 80C then things started to happen. Very erratic pressures and voltages, and when RPM was near 1000, all pressure sending stopped at something around .360V and something under 600mbar..... thus the deduction of sending unit failure. Ordered the sending unit from the local Dealer (got a good price!!! :-) ) and about 3-hours of work I replaced it (not the easiest thing to get to).....however, no more errors!!!

The problem is the new software version for the Cayenne has basically been bricked for diagnostic... there are no actual values output from the SDI4 V8 engine module... This should be simple OBDII data readout...

Okay, found a copy of the Durametric 6.1.1.3 software, and it works and reports actual values. The oil pressure is approximately 2300mbar at idle, 640RPM (oil temp 70C) and 4200mbar to 4400mbar at 2500RPM Oil pressure reading is a bit eratic as well as voltage for oil pressure. Again, the problem doesnt arise for a while... I'll have to take it on a test drive again with the monitor attached and watch/record the errors when they happen. From the surface, seems like the sending unit!

Yea! I found a download on one of my other computers of 6.1.1.3 .... It works!

The Actual values for the engine are not responding, RPM, Fuel trim, Oil pressure, etc. I have the car parked because I cannot diagnose the Oil Pressure Monitoring fault... Because Porsche periodically changes the game by switching DME suppliers and the like, Durametric is always playing catch up. And when Porsche does make an unannounced change, shops or end users are the ones that discover it and report it to the Durametric crew. That said, a couple of months is not at all unusual time frame for them to find a work around to address it, and often it can take a lot longer. I have always found the Durametric crew to be upfront when some problem pops up, so I wouldn't be quick to label their frankness as poor customer service. You may not like what they have to say, but they don't sugar coat things, or over promise and under deliver. At the end of the day, unless you have the bucks to jump for a PIWIS lease, they are still the best alternative................ Yea, but it's been a couple years since they said they would fix the transposition of the error codes... still not done on the Cayenne! The frustration has been being told it would be soon, fixing the current problem and having ther car parked waiting....

Having issues with my Cayenne and went to use my Durametric software and there are no real time actual values available... Talked with Durametric nearly a month ago, they were aware there is a problem...sent data logs to them to help. Sent a followup e-mail to check progress... no answer. Called today and was told they don't know when it will be fixed. I asked if there was an older version to run that did work... No! we cant offer anything to help... no idea when it will be resolved... Absoutly the worst customer service attitude I have experienced... I have the Durametric 6.3.2.5 version ... does anyone have a copy of the earlier software that worked?

Thanks Dan, I'll consider them. After 19K on my Michlein Latitudes, still another year if tread left (they were in the car when I bought it used) they have performed very well and going to the new LRR Michlein (265/50/19 N0) has some interest.

I think so, it runs for a while before the warning appears. If it were truly mechanical, like the oil pump, it would not be intermittent or delayed.

Okay, being an old man with a bad back, cleaning the OEM '08 Cayenne S II triple spoke wheels are hazardous to my back... I decided to buy a set of the 19" Cayenne Design wheels. I also was not fond of the sidewall profile of the OEM tires and 18x8 wheel... I don't like tires that are significantly wider than the wheel... thus the 19x9 wheels. The used set of OEM wheels came with 2 sizes mounted... 255/50/19 and the OEM 275/45/19. With the slightly narrower tread width on the 255, both are similar in total section width. I am pondering sizes... the OEM 275/45/19 or the newer OEM for the 19x8.5 wheels, 265/50/19. Tire brand is a delima, the OEM when I bought the '08 Cayenne S at 62K were the Michlein Latitude H/P ... I now have 80K on the car and really can't tell how much the tires have worn. Sidewall cracking is more of an issue than tread life at this point. The new 265/50/19 110V N0 Michlein Latitude H/P is a LLR tire with a higher load rating and cheaper than the 275/45 The usual delima is Wear, Handling, Tread life and Noise ... having a tough time deviating from the Michlein because of the acceptable performance I have experienced, however they are more expensive than many other Porsche approver tires. Any comments? Thanks, Glen

Suddenly the other day while rolling to a stop, the warning message "oil pressure monitoring system failure" appeared... As I increased speed it dissapeared till I slowed again.... Since oil change was due (80K), I changed the oil (0w40 M1) and filter. I disconnected the oil pressure sending unit and reconnected (no easy task) ... took the car for a test drive and all seemed fine... after about 10 minutes of driving, the warning returned, but only when the RPM dropped below 1000. The "oil pressure too low" red warning also intermittently appears. While driving further, the RPM trigger point rose to about 1500RPM. The warnings all go away as soon as the RPM increases and only reappears when the RPM drops below the trigger point... My Durametric software is malfunctioning, it will not return actual values. When they get it fixed, I will check the info coming from the sending unit to see if the signal is erratic. If the sending unit need replacement, I'm not looking forward to the cost (~$170) and work getting to it. Looks like the cooling fan needs to be removed to be able to reach it. Anyone else have anything similar? Glen

The sunroof should have 4-drains. The two in front should be able to be cleaned with compressed air. To check the drains, you can pour some water in the drain channel and see if it drips out in four points under the car. The rear drains are a bit more difficult to reach.... possibly some small semi rigid plastic tubing. Start lightly with the compressed air, not sure if there are any rubber connections that could be dislodged.