Zakowsky

Interesting, thanks Loren. I believe the 996TT uses a slightly different mounting system than the 997TT, but the idea that this could play a role is something for me to check. I feel pretty dumb, but I figured out the shift - I had no idea the PIWIS auto scaled each trace separately - duh. So they are in fact not shifted. But unfortunately I still get the P0021 coming right back. I think the problem is that although it tracks most of the time, there are times that Bank 2 just doesn't respond at all like Bank 1 - so in that graph like at the arrows. Looks like the variocam is sticking sometimes. Is there any oil "flush" that is safe and useful for this engine? I used SeaFoam on my Jeep, but not on the Mezger...thanks.

Thanks Loren, I have read through all the documentation on this, and scoured the online resources. Just wondering if anyone has seen these kinds of logs before - I believe the variocam works by the oil pressure from the holes in the camshaft sleeve shifting the helical gear in the adjuster one way, and the oil from the solenoid pushing it back the other. So since the timing shifts both ways fine, it seems these circuits are OK. So the only way this could be the variocam is if maybe the bolt that holds it on the cam shaft is loose maybe? And that causes the offset to come and go? That would mean it would be bad to even run the engine, I would think. But you would think there is a pin or something to hold the variocam to the camshaft...thanks.

Hi all, I used to contribute a lot here regarding the Cayenne TT, but I haven't posted in years - my Cayenne Turbo went the way of all things and now I have a 997.1 TT to fill my time. I am really at an impasse now, and as I saw some threads regarding the P0021 situation here I was hoping Loren or JFP or anyone might have some experience with something like this. I had a P0021 with the Signal Implausible clause (read from a PIWIS 2) after a 3-4 shift at WOT with a puff of black smoke out the back. Sure enough Bank 2 did not respond any more to throttle blips. I replace both actuator solenoids, and the solenoids and actuators seem to be working now. But after driving for a while I would see the offset between the 2 banks jump all of a sudden, and bank 2 occasionally not track bank 1 If I stop logging and reset the PIWIS they start moving in sync again! Which I thought might be the PIWIS, but the P0021 comes right back when this happens, so it seems real. So I was previously worried obviously about spun cam sleeves, but if the solenoids and the actuators are working, then that seems less likely. I am at a loss for what to try next, the only things I can think of are 1) Camshaft position sensor is faulty - but that should generate a different error code, shouldn't it (like P0343 for bank 1)? 2) The camshaft has jumped a tooth - but then wouldn't the offset always be the same? 3) Something is sticking inside the Bank 2 actuator. To note, when I replace the solenoids, I found that the Bank 2 solenoid had not been installed properly, so it is possible it had had compromised function for some time. So maybe the bank 2 actuator works to adjust, but the base offset gets stuck? I am not sure how the actuator is designed. Any ideas would be appreciated, before I resign myself to tearing this all apart. Thanks, Mike

Your best bet is to buy the CANBUS decoder from the manufacturer of your HU, assuming the additional harness is for the adaptor. The CANBUS decoder will be specific for decoding your model vehicle, and communication with the HU specific to the HU manufacturer. Just so you know, it might not work perfectly, as the Porsche CANBUS is a bit different than most it seems. But if you don't have a CANBUS now, I don't know what would be causing the clicking...I'd sort that out first and make sure it isn't a current draw, especially if it happens when the car is off and the key is out. ACC switched taps in the fuse box are not easy to find - where did you connect it too? If you just connect the HU ACC line to the power line, does the clicking go away? If so maybe your tap point isn't ideal...

If your new HU has a supplied CANBUS adaptor, they can use different protocols to keep the bus alive when the vehicle is off but the key is still in the ignition. The first adaptor I tried did the same thing, kept clicking a relay in the dash. But the company sent me a new one which worked by a different method I guess and it doesn't click. The fact the SWC don't work also suggests the CANBUS unit is jacked. But the clicking never seemed to be anything but annoying, and you can use mtcdtools or the equivalent for your unit for the buttons if WheelKey doesn't work.

There is a bit of a trick to it - if you feel around back of the mount, there is a small spring loaded lever that drops into the slot on the roof rail when it is in the correct spot. On mine, if you push this down a bit further so it is firmly in the slot, the side closes easier. If you have to force them, the locking lever might not be exactly lined up in the track. I practice, I just push the back lever down and shake the rack back and forth a bit until it feels exactly settled correctly, then the sides snap closed easily.

I'm going through this as well - bought some non-Osram D1S bulbs (wanted 8000K...) and they seem to have toasted one of my ballasts. Live and learn... The pictures you posted are of the calibration procedure your new Valeo units need, however although VCDS will perform a lot of functions on the Cayenne, I can not get it to communicate with modules 55, 29 or 39. Plus I don't think Durametric communicates with them either, so this has to be done at the dealer. The only way around this are supposedly to buy used LAD5G ballasts/control units. I would imaging this works (if it does in fact work) by virtue of a "calibrated" bit being set in the control unit. Although I am surprised the main ECU doesn't also check for a known, calibrate serial number on the ballast. If you run a ballast from another car without calibrating it, I suppose the vehicle it came from should be the same in terms of having air suspension or not etc., so the lights come out at the correct level. If you are still working on this I can post how it goes with an older replacement unit.

Just realized we are having the same conversation on Rennlist! Here is the link to the pdf, which has a link to the site, for people here. http://trioma.ru/products/most/pdf/most-amp3.0_eng.pdf If anyone has experience ordering from these guys it would be great to hear about it. Apparently there is a new version 4.0 with is improved. About $160 US.

If you are replacing the amp, consider not putting a Bose back in - get free of the MOST system while you have the chance! With a nice (and expensive) HU like the AVIC just run RCA lines to the back and put in something like a JBL XD600/6. With the MOST adaptor you do not have front/back fade control, and in my CTT anyway it really needs the sound shifted to the rear speakers. Plus the sub performance is questionable. This is what I am getting around to doing with mine. Lots of threads online of people who have done this.

Happy New Year Thomas! It's been -30 Celsius here in Calgary, but the CTT is still eating its way through 4 foot snow drifts and a sheets of ice for highways. I'm hoping nothing serious goes wrong with it, because it is too cold even in my garage to work on it! Cheers.

Just to finish this for people searching for oil smells and such...the new Porsche N80 valve solved the errors and the engine is running smoother than ever. The oil smell blowing out the vents when I went over a bump, or slammed on the brakes, was just as strong right after the fix, but over the past week has faded to almost (but not quite) nothing. So I suppose the oil vapors that blew by the valve when they were not supposed to condensed and collected somewhere, and were splashed loose when bumped. That reservoir of crap just took time to slowly clear out. So engine is quite good now. But don't worry, still things wrong - driver side door open/closed micro switch is not working, which doesn't seem that big a deal but things like the fuel pump not turning on early can lead to misdiagnosis, plus it is really easy to lock your keys in the car because it re-locks the doors thinking you didn't get in! Should be time consuming to get to the door latch. Plus a replaced cable for the passenger window sounds like it broke again so all that has to come apart. Would be nice to be worrying about what kind of wax to use for a change!

Quick note - codes are still gone but it didn't help the blast of oil smell unfortunately. I hope the codes don't come back too. Looks like they were maybe unrelated after all. Still have the Secondary Air Pump not ready warning that has always come and gone. Maybe the oil is something to do with that. Edit: Over the course of the day the smell is getting less and less. Perhaps wherever the oil pooled is slowly getting cleared out. So still hope. And it is definitely running better.

It's late here and just returned from a test drive and so a quick update. You were correct Lewis, looks like I should have just replaced the N80 to start with. And thanks for the tip Thomas - those were the kind I was going to get. Anyways I really needed the car tomorrow and was looking at the $150 one sitting in the garage and just said ok Porsche wins this round. Installing it was a lot easier than taking the old one out; fired it up and cleared the codes, drove for 30 minutes and no codes came back and actually didn't smell any oil anymore. No bumps or hard braking, will test that out tomorrow, at least fool myself it is fixed for one night! But the idle is noticeably smoother and it even the "Evaporative Emissions" readiness check was green, something it hasn't been in a long time. Will see how the next few days go but looking OK. And btw I was wrong about the mechanical air pump; on the turbo with the electric ones there is no mechanical one that runs off the back of the camshaft.

You're right Thomas - but I just went and bought the new part, and when I got home and looked at it, it says Bosch on it but it is Made in China! Plus it has the white paint on it like a remanufactured part. If Porsche themselves are selling non-OEM parts what are you supposed to do any more. I can still return it, and maybe order it from Germany or something?

An update - inspecting the EVAP stuff in the rear wheel showed no sign of problems, couldn't find any leaks or broken wires, so I removed the N80 plus the hose from the engine. It was a PITA as there a lot of plastic there I didn't want to break. Anyway once removed it I tested it again and found that sure enough, when I hit it on one side it would open, then when you hit it on the other it would seal closed. Explains why it would throw codes after going over bumps. Tried to clean it out but no luck, and I can't crack the casing open without destroying it. Has anyone tried using a VW or Audi N80 instead? The Bosch part number of the Cayenne valve is 0280142398, which only matches up to the Porsche version. Touareg's use one that looks identical but the Bosch number has a different last 3 digits. Reason being is you can get the Touareg one for like $20 online, and here in Canada the Porsche N80 is $148. Either way this should fix the problem and I can finally get this back on the road.