deilenberger

An update - this is also posted on 6-speed-on-line, so if you browse the 958 forum there, you may have seen it already. But in the hopes of bringing some technical activity to RENNTECH - here goes: In one thread somewhere (?) a chap showed a photo of his repair bill for the new transfer case ("X-case" from now on) he received. He mentioned that Porsche had changed the design and that included a modified X-case vent that vented up higher. On his repair order was the PN of the vent - 958-301-047-10. Available from Sunset Porsche for $28.71 (plus shipping.) I thought I'd drop by my FLD* and give them a shot at it, and see if I could glom any more info. Turns out it was a good day to do that since they just finished replacing a X-case on a 958 /S - and had the old one on the shop floor waiting to get boxed up and returned to Porsche. What I found out: - The X-cases are still made by the same manufacturer. Indeed - the ones available are generally REBUILT ones done by that manufacturer. So - same basic design. - The vent IS a change. On the existing X-Case the vent comes right out of the top of the large cylindrical part of the case (where the clutch lives) and is capped by one of the rather common fish-mouth sort of rubber caps that Porsche so loves (they are a sort of 1-way device - at least supposed to be for moisture. Maybe.) This cap just slips over a small hose sort of fitting that threads into the top of the case. The idea being that air can pass through the fish-mouth part of it Took forever to find this: Transfer Case Vent - photo shamelessly borrowed from eBay. The old transfer case was right there - so I got to look closely at it. As part of the kit - the fitting on top of the case is unscrewed and a new fitting screwed in that connects to a corrugated plastic tube (Porsche is SO fond of these..) The plastic tube is then run up the firewall into the engine compartment - with all sorts of neat fittings and clips and tie-off points. The idea being - move the input to the vent to a dry heated area. Problem is - the clearance isn't there to do this replacement with the X-Case in the vehicle. BUT - my thinking is - simply remove the rubber cap/seal - put some high-temperature teflon tubing over the end of the existing fitting and run that up into the engine compartment. Come up with some way of using the existing rubber-seal on the end of that tubing. So - that's the plan. I'll be doing this while changing the X-case fluid. The shop-lead mentioned that the fluid is spec'd as "Lifetime" fill - and I just pointed to the X-case sitting on the shop floor - that apparently had exceeded it's lifetime. He agreed that a change of fluid is probably a good idea. Next challenge - which fluid? There is 000-043-301-36OEM - which was "superseded" by 000-043-305-63OEM. Cost at the dealer was around $75. Cost from Sunset Porsche is $47. I gave the dealer a chance to make the sale - but the difference is simply too much, even figuring I'll have to pay shipping from Sunset. The first oil is also available from Pelican for less $$, but I think I'm going with the new oil. Oh - one other change the shop lead mentioned they make to the new X-case - is a new slinger on the output spline shaft, apparently to toss water differently from how it's tossed now if the vehicle is driven in heavy rain or water. They were told that the "fix" for the cases is to keep the fluid from getting contaminated - and that's the reason for these modifications. I'll try to remember to take some photos. * FLD = Friendly Local Dealership

Thanks - I saw the Pelican listing, and the alternatives they list may be fine, the Shell is the same oil Porsche relabeled and sold, and the other I'd like to hear from someone who has used it. What's interesting - if you look at the Porsche/Shell fluid - the details on the oil notes that "Part Number 000-043-301-36-OEM has been superseded to 000-043-305-63-OEM" - doesn't say when - but I imagine Porsche has a reason for changing the fluid.. So - it might be a case of me getting the expensive factory fluid with the new PN.. Grrrrr..

Folks, On another forum I follow, there is an ongoing thread on transfer-case failures and replacements. Some people have experienced multiple failures, many people none whatsoever. One person showed a photo of his repair order, which included something interesting. Besides replacing the transfer case, they also replaced a vent hose for the transfer case. When he asked his service adviser - the adviser said Porsche had issued a WB (workshop bulletin) instructing them to replace the vent hose when the case was replaced. The open end of the vent hose was now located above the level of the transfer case, where before it ended low down on the transfer case. The explanation for this by the SA was that Porsche determined that moisture was getting sucked into the cases and causing fluid contamination. Since the Xfer-case uses a multiplate wet clutch (much like a common design on motorcycles) - I can see where moisture might cause corrosion or rust that could cause the clutch to bind and work erratically - giving the symptoms described on failing cases. So - I'm going to order and install the revised vent, and also do a preventative fluid change at the same time. Since the Porsche fluid is silly-priced (about $80/liter) - I thought I'd ask if anyone has an alternative that they've used. There are several "transfer case" fluids that I've seen mentioned as alternatives, but I'm looking for first hand experience here.. who has used what? For those interested - the PN for the revised vent is: 958-301-047-10. Roughly $30 from Sunset (least expensive I could find.. but I'm giving my FLD* a shot at it too..) TIA! * FLD = Friendly Local Dealer

What model do you have? You should be able to determine if your car has Servotronic by doing a VIN# search one any of many available websites that offer it. It might be bundled in a "package" depending on your model though. One chap on another forum took his Servotronic fuse out of his 958 claiming it greatly improved steering feel at speed. He did note that the car became much heavier to steer at low speeds though. If you have Servotronic - first thing I'd look at is the fuse. Second thing is hook it up to a good Porsche code reader and see what faults are hidden away..

I think spending a bit of time with your owners manual would be productive. What I don't understand is you apparently used to own a 957 Cayenne - and in my experience - the 958 HVAC system behaves much the same as the 957- with the exception that there is actually some heat sent to the drivers tootsies when called for. The "Defrost" button is also a "Defog" function - and the behavior is EXACTLY what's expected and EXACTLY what your 957 should also have done. It's max temperature - all the heater is capable of - with the AC evaporator chilling and DRYING the air before it's heated by the heater core. As far as your other problem - what is an "air toggle" that you're turning on? I suspect if you set the HVAC to AUTO mode, and simply adjust the temperature the system will do exactly what you hope and want it to. In AUTO mode it will speed up the fan and crank up the heat in response to an increase in the desired temperature setting. When the interior of the car reaches the desired setting it will turn down the fan and lower the heat in order to KEEP it at that requested temperature. This is all assuming that engine is hot. If you just started the vehicle - the fan doesn't increase much in speed since the engineers figured it was better to NOT blow cold or cool air at you when you're asking for hot air. I don't think you have any problem - except understanding how the system works. Mine sits in AUTO mode on both sides, the temperature set to 72F, pretty much all the time. On very rare occasions I find it necessary to press the DEFROST button - but after it's defrosted and I press the button again it reverts to the same mode it was in, AUTO @ 72F.

On another forum - there are some rather long discussions on the XFer case failures. Some people have experienced multiple failures, most people not at all. Supposedly (wasn't me so I can't swear to it) Porsche changed suppliers (sounds unlikely to me.. but that's the claim their service managers were making) - and one for sure change they've made is the location of the end of the XFer case vent line. Apparently the line used to end low, almost below the bottom of the case. They've modified the line so it now ends up high above the case. The supposed reason was to lessen moisture being drawn into the case. If the clutch plates - which apparently are metal to metal - started corroding, they would possibly tend to bind and then release instead of smoothly slipping. It sounds as if this was Porsches diagnosis of the problem (and fix.) I think that also puts some urgency into more frequent changes of the fluid in the xfer case - to remove any contamination/moisture. It may be why certain vehicles suffer multiple failures and others none at all - environmental conditions combined with use patterns may mean some owners/vehicles will experience more rapid contamination of the clutch fluid, leading to more rapid deterioration of the clutch. I know there was a recall on early 958 vehicles for defective clutch assemblies in the xfer case. The claim was made in the recall that the defect was a machining error on the clutch case. The symptoms were identical to what people are now experiencing with a wide range of production date Cayennes (the newest I've heard of is a 2014 - so far..) Anyway - the PN for the new vent tube is 958-301-047-10, around $29 from Sunset (cheapest I found it on line - I'm giving my local friendly dealer's parts department a shot at it - if it's close enough in price - they get the business.)

Brad, I'm sure Porsche does have lots of attorney's out there - probably reading this shortly after I write it.. but a pigtail wiring harness isn't something that can be copyrighted or patented, especially when other vehicles use the same connector (Volvo uses this same connector - with wires going to it - I know because the clock I bought off eBay came with a Volvo connector that I elected not to use..) The connector can be found with some searching (I seem to recall finding it as a Tyco product), but putting one together requires special tools to push the connectors in place - and that also was something I decided to pass up on. It seemed simpler to pay the $90 and get one that was made for the job. A lot of searching last night turned up the source for the cable I bought - again. From Hong Kong - again. Price went up to $100.99. The link is in the other thread. One chap on the other forum did persist on the Porsche Part# that was in the thread, and one finally arrived. He PM'd me last night. It isn't what he expected. It is what I expected seeing the illustration in the parts listing. It's a three-connector cable assembly. Perhaps one of the connectors is the correct one for the clock (that isn't clear yet) - the others are for something else. Makes sense since it was spec'd for a Boxster originally. I'd love to find the elusive Porsche parts guy who really knows how to work the parts system for things like this, I used to have a Volvo guy and a BMW guy - but haven't found the same sort of guy at a Porsche dealer. I think the difference is - the parts guys at Porsche can't afford a Porsche - even used - so they're not as enthusiastic. The Volvo guy and BMW guys were both enthusiasts who happened to channel their enthusiasm working at the parts counter.

Brad, et.al: You're probably referring to http://rennlist.com/forums/porsche-cayenne-forum/774703-dash-top-chrono-clock-harness.html - The OE clock is easy to find, finding the wiring is not so easy. There is a guy selling a "kit" of the panel, clock and wiring - he wanted silly money for it ($700 or so) on Ebay. I asked about him selling just the harness since I owned several of the clocks - and he wanted $250. Silly price. One popped up for a very short while on Ebay - from Hong Kong - for $90. I jumped on it and it was delivered fine to me. Apparently whoever that was has now disappeared off the US Ebay site. He does appear on the Euro Ebay sites - selling various accessory parts and bling - but won't ship to the USA. Other people mentioned finding a Porsche supplied harness for way less money - but none of them ever reported success in ordering it so I'm guessing that's a pipe dream. Oh - besides the clock working just fine - it also gave me the sport-chrono timer option in the MFD. Trigger button for it is the right side steering-wheel button/wheel. Besides the standard clock, I also have a dash mount sport-chrono, but since I'm not doing laps in the Cayenne I opted for the standard clock. The sport-chrono makes a nice looking desk display, even when not keeping time - but in a Cayenne it would basically be bling (although it does have a digital time display built into it..) The most fun of the dash top clock - watching the hands do their dance when you open the door..

I suspect the oil on the sensor is a non-issue and is probably just a tiny bit of seepage around the seal for it. You got some good advice - but can't see that you really followed up on it. You seem to have lost wrenching interest with the coils.. :-) LESSON: If one coil has crapped out - the other ones are just sitting there thinking about crapping out. They are all the same age and operate in the same environment for the same amount of time. DO all the coils. It was suggested you start checking for hose leaks. I'll describe a method I've used in the past - but am not suggesting you do since I don't know your skill level and you might destroy life as we know it. It involved using something flammable to try to find intake leaks. It should be done OUTDOORS with a really good fire extinguisher handy, with proper eye protection and clothing that won't go up in a puff of smoke. I usually use some flammable carb cleaner - some people use an unlit propane torch. The carb cleaner has the advantage of being quite accurate since I spray it using the red-plastic tube that comes with the can (and when I can't find the tube - it's in the darkest corner of my garage - spiders seem to take them to build nests or something.) I use the spray giving TINY little spritz's of it around any suspected leak points while the engine is idling. ANY (and I'll say it again **ANY**) change in idle means there is a leak where you just sprayed. I'm very careful not to spray on things like the exhaust system, or anything else that might ignite the carb cleaner. In this case - I'd be spraying around the multitude of corrugated plastic pipes that run around the engine, the throttle-body, and the MAF sensors. FWIW - the MAF sensors can be cleaned. They usually don't need to be - but if someone ever used an oil-cloth/foam air filter on the vehicle they quite likely would need cleaning. Hike down to your friendly local auto parts place and look for "CRC MAF Cleaner" - you remove the MAF, and spray the part sticking into the airstream. It's a flat hot-film sensor. Let it dry completely before reinstalling it. There are two of them on your S.. I'm trying to remember what triggers a throttle-body relearn - but I believe it's done when you switch on the ignition and then simply press the gas pedal to the floor without the engine running. You may have to do it 3 times, but I think not. You're just teaching the ECU the travel/vs/resistance reading of the gas pedal and syncing that to the two check-sensors on the throttle body. The top engine mount is also suspect (as was suggested to you.) Use a MAGLITE and look very carefully at the rubber bushings. ANY sign of cracking of the bushings means it's toast and should be replaced. There is also the possibility the lower mounts are sagged - but they're a lot harder to check and on some models (the turbo for sure, not sure on the S) the engine has to be dropped, or the suspension subframe dropped in order to replace them. Bad mounts will allow engine vibration to travel into the vehicle. As far as the "1355 Valve Lift Control, cylinder 3, implausible signal" error - does it tell you if it's presently active? Or how many times it's been captured? I'm not sure how that measurement would be detected - on "cylinder 3" - since the camshaft sensor is on the back end of the camshaft. I suspect it may be looking at the firing time vs the camshaft position for cylinder 3, meaning a bad coil might well give that error message. I'm sure some Porsche tech could tell you. Good luck - let us know how it works out for you.

BTW - most people (me included) find 21" tires somewhat harsh riding on a Cayenne. I prefer how my winter 19"s ride. Other people on other forums have commented on 22" - and the comments weren't generally favorable. But if you're form over function - it might be just what you want. It won't improve performance - the increased weight of the rims/tires will actually decrease the performance.

What is the rolling diameter of both front and back? If it varies by more than about 5% before long you'll be looking for a new transfer case. Porsche has spec's for the permissible difference in diameter for a reason.

One small comment on the transfer case. In another forum in a longish thread on 958 transfer case (AKA-TC) failures - someone posted a receipt from a dealer who tested the TC by unplugging the controller motor (I imagine that does trigger a driveline failure message of some sort.) When unplugged the TC didn't exhibit the symptoms. The dealer seemed to conclude that was a conclusive test - and replaced the TC, to the customer's satisfaction. A new TC was bought for ~$2,500, labor/parts to install it was around $500. List price on the TC was much higher, but looking at some on-line parts sources, $2,500 is not an unknown price from a Porsche dealer. Strangely - people are paying more than that for used ones on eBay. Big "duh" to them on that..

Searched the ZF and Aisin websites. Found references to Porsche/Cayenne on the ZF website - but not for transmissions or driveline components. Found references for Porsche for automatic transmissions on the Aisin website - but no specifics as to years/models.

I've been searching for the reference to ZF and the 958 series that I saw and so far am coming up empty. I distinctly remember being surprised that they had changed vendors from Aisin - which is why I remembered it. I vaguely remember it being in some Porsche promotional material, but so far I haven't been able to find it. I'll keep looking..

Some more research - lead me to: http://www.pentosin.net/f_transmissionfluid.asp - which in searching turns up their ATF 1 LV as being compatible - both with apparently the 8 speed ZF boxes and what appears to be the 6 speed Aisin boxes (also used in lots of Cadillacs and Toyota/Lexus vehicles.)

AutoAtlanta lists alternatives specifically for the 958 series: http://www.autoatlanta.com/results.php?partnumber2=958 300 540 00&page=1 - these include the Febi Bilstein replacement fluid. At $13,000+ for a replacement transmission I'd like to be certain that what is going in is the correct fluid. Here is the Pelican page for the same thing: http://www.pelicanparts.com/More_Info/95830054000.htm?pn=958-300-540-00-M36 - a bit cheaper. Sunset Porsche has the factory oil for somewhat less than most other on-line dealers: http://www.sunsetporscheparts.com/oe-porsche/95830054000

I thought the 958 8-speed is a ZF built transmission, not Japanese. The Fuchs website doesn't list this as compatible with the Porsche fluid. Pelican may be correct for the 955/957 6 speed transmission built by Aisin transmissions, which indeed are Japanese. http://www.fuchs.com/us/en/special/product/product/titan-atf-4400/ From the Fuch's website:

Are you certain the engine is missing? Or could it be a brief driveline slip? The transfer cases on the 958 are known to be a trouble spot, and are appearing on more and more forum posts (on other forums - this one is almost dead on 958 topics.) The failure exhibits itself as roughness felt when accelerating, and sometimes more noticeable when turning. The failure appears to be in the clutch assembly. Dealers are getting ~$4k to fix this - new transfer case (not hard to put in actually, but expensive to buy.)

From the AllData website (info there is from the service manual):

Wrong forum. You have a 9PA. You want to post this in: https://www.renntech.org/forums/forum/31-9pa-9pa1-cayenne-cayenne-s-cayenne-turbo-cayenne-turbo-s/ And a question - what tool are you using to read these codes? If it isn't a Cayenne specific tool, any code above P999 is questionable since those numbers are manufacturer and model specific.

Do you know if your 958 was the subject of the EGR oil separator recall/campaign?

What you do want is PROOF (a receipt perhaps) that the maintenance was done. At least a receipt for the parts. Without that Porsche can legitimately complain that you may not have properly maintained the vehicle.

If you have a cell phone - you can simply ignore the SIM card slot and just bluetooth your phone to the Cayenne. That's the simplest way. The Cayenne doesn't use the internal phone guts for anything - the traffic info is over Sirius/XM and costs you about $9/month (more if you want entertainment.. but they do respond to dickering..) The Bluetooth is depending on your phone - not the carrier. My Verizon phones seem to hook up just fine.

That might be true - but you won't sell yours cheap right?

Yes. A cheap used German car may be the most expensive car you've ever owned.