geoff

I asked my service advisor last night for specific measurements, but all I got back from him was "Oil cap hard to remove", which in all fairness is his level of mechanical expertise and understanding (he came from Porsche sales and doesn't know much about how the cars actually function in terms of problems, and the techs know this, but he does go out of his way not to sell unneeded work). I don't doubt the AOS is starting to fail after 14 years and around 150K miles (no visible symptoms yet), but more worried that replacing the AOS won't solve the cold start stalling problem (only stalls after initial cold start in the morning with the headlights on, but never after that). I'm going to the dealership to talk to the techs and get the details firsthand, and will report back what they say. And it's not like I don't spend enough at the dealer that they need to make more money off of me. I went deer hunting on a canyon road at 60 MPH, and instead of filing a comprehensive claim with my insurance for my '08 Cayenne, I'm having the dealer fix everything, including subletting all the body work.

Thanks Loren, as always! None of these are sounding like they are caused by the AOS going bad, are they? I'm going to visit the dealer to see what's going on tomorrow. From the way my wife has described the symptoms, it seems like it would be a fuel or electrical issue causing the car to sputter and/or die. The CEL didn't start until after the first visit where the tech cleaned the throttle body. Before that, it was idling smoothly, just stalling. I'll see if I can get more details. Anything else this could likely be?

Original owner 2005 997 Carrera Tip, 191K miles, my wife's daily driver. Engine replaced by Porsche in 2011 around 60K miles when IMS bearing let loose. Lately in the morning on cold start, the car stalls at the end of the driveway first thing in the morning with the headlights on. Then runs OK, or sometimes stalls one more time in the next block. Doesn't stall when the headlights are on, but stumbles once or twice in the first few minutes of driving in the morning, then all is fine. Took to the dealer (never had any complaints), and the tech cleaned the throttle body. Check engine light came on by the time I got it home and the car continued to stall in the mornings. I'm in So Cal, so cold start is in the 50s outside temperature. Codes are P2189 and P2187, which indicates the engine's air-fuel mixture is too lean on bank 2 and bank 1 while idling. Tech then said found broken line for brake booster and replaced. Check engine light still on. Car still stalls. I then replaced the 9 year old Optima with a new AGM battery, but that didn't solve the problem. Back at the dealer this morning. Service advisor is now telling me the techs think it's a bad AOS, even though the car isn't smoking. Story is coming from 3 techs, including shop foreman. Their diagnosis was based on oil cap is hard to remove, and "oil filler neck is sucking in". I asked for what pressure measurement they got for crankcase vacuum, but didn't get a straight answer. Before I spend $4K to replace the AOS, which doesn't seem to me that it's the cause of the problem because there's no smoke on startup, what else should I have them look at?

'01 986 ~110K miles, all original O2 sensors. Check engine light periodically comes on, and then after driving a while turns off. Codes are P0139 and P1117. Is this indicative of anything other than an aging / failing O2 sensor? This used to happen every couple of years, but now appears every few months. Car runs fine except for the light on the dash

My problem as originally posted did not show anything pending or actual as far as fault codes on the Porsche dealer's Porsche diagnostic computer tool. They told me to drive it a bunch and the readiness would set itself after a few hundred miles or less. Many, many hundreds of miles later, I resorted to the half throttle immediately after starting and that set the secondary air readiness finally. It's likely some sensor component that still works on these 20+ year old 986s enough to drive around without throwing an error, but is still out of spec

Unfortunately, I live in CA, so readiness not being set means the smog test can't be run. After around 2K miles over the past almost half a year since getting smogged, no check engine light. I'm going to hold tight and see what codes look like in about a year and a half the next time I have to go through the whole smog check experience again

No kidding! But over 750 miles seems a bit excessive. I was going to take my car back to the dealer and leave it so the head tech could do a cold start in the morning and see what's going on. When I started to go out there this afternoon, I tried revving the engine to 2800 RPM for 2 1/2 minutes with the defroster on, instead of letting it idle to start the drive cycle. Then plugged in my cheapie OBD tester, and lo and behold, all readiness indicators were set, including the secondary air injection. I didn't go out and buy a lottery ticket, but I stopped by my usual smog check place, and all readiness indicators were still set, no CEL showing, and my car passed the smog test, so I'm good for 2 more years. I went by the dealer afterwards, my service writer said there's nothing for them to do, then I chatted with my mechanic for a while. He hadn't heard about this, but figured at 2800 RPM there's a lot more air flowing through the system, which gets the onboard computers to recognize readiness.

There were several posts on the topic, but after reading through all of them, I don't think I ever found a definitive solution as to fixing the secondary air readiness. About a month ago, I started driving to get my '01 986 smogged and got a CEL. Code reader showed it as a vario cam bank 1 problem, and after some diagnostics, it ended up being the actuator (which also includes a new solenoid), which my mechanic at the dealer replaced. My car drove better than ever, but after driving around for several days, when I went to get it smogged two readiness indicators weren't set. I tracked down the drive cycle description, followed that many times, and every time I checked the secondary air readiness still wasn't set. I made a trip back to the dealer today, head mechanic confirmed the secondary air system is functional by turning it on with Porsche tester, no fault codes showing, but still couldn't get secondary air readiness to set. He disconnected the battery, hoping clearing everything would solve the problem, so I drove around doing some errands, and by the time I got home everything was good to go except secondary air readiness. So I still can't take it in to get smogged. I'm going to drop it back off at the dealer later in the week so they can do a cold start in the morning. Any suggestions as to what is known to solve the problem since all the prior posts on this subject?

The HVAC blower in my '08 Cayenne started making a loud noise and vibrating, which seems like a common problem as these vehicles age. The OEM Porsche part 955-572-342-02 shows a retail price of $750.27, and even the online Porsche dealers selling parts at a discount only took off 10%. From watching a couple of YouTube videos and searching for aftermarket parts, it looked like the Cayenne, Touareg and Q7 all share the same HVAC guts. Knockoff replacements are available for under $100, but looked a little sketchy and are made in China. One video showed the replacement being a VW part, so I took a chance and ordered the VW part 7L0-820-021-Q, which retails for about $480, but available online from VW dealers for 25% off. The VW dealer a block from my Porsche dealer got the part in a day, and with no shipping, I still saved about 50% over buying the Porsche part. When the mechanic pulled the old blower out, the VW part stamping on it exactly matched the new one I just picked up. With all the shared parts between the Cayenne and Touareg it definitely pays to do a little research if you want to save on "genuine" Porsche parts

Thanks for confirming. And thanks for clarifying AGM and gel are different technologies. I googled the difference between the two to get smarter on the technologies, and definitely meant AGM

It's time to replace the starter battery in my 2008 Cayenne S. Porsche calls for p/n 9A7-915-105-C, which I think has been superseded by 999-611-110-20, at least according to the dealer parts guy. It's a 110 amp wet battery. We measured batteries in parts today, and the newer Cayenne AGM battery, 958-611-105-21 looks to be the same size. It's a 105 amp gel battery. Can I just install the newer model AGM battery in my '08 S and the terminals will be in the right place? I know specs wise it should work

Sorry, I don't look on here very often. Not sticky, but the black was coming off on the temp and fan control on my 2005 997. I pulled the HVAC control and sent it to Sticky No More - Exotic car interior refinishing services STICKYNOMORE.COM Industry-leading plastic interior refinishing for exotic cars to make them Sticky No More and they did an excellent job, reasonably priced and fast turn around

To answer my own post - a while after posting, I found a local transmission shop that had the smarts to figure out the problem. The guts of my transfer case was made by Borg Warner according to the transmission shop. I found replacement seals and belt at NP 235 Transfer Case Kits | Cobra Transmission COBRATRANSMISSION.COM Are you looking for the best NP 235 Transfer Case Kits for sale? Shop all NP 235 Transfer Case parts today at Cobra Transmission. The noise I was hearing was due to the belt stretching out over the years, and hitting the inside of the transfer case housing under load. Here are a couple of pictures of the inside. In the almost 2 years since I had the transfer case rebuilt it's been problem free

2008 Cayenne S, making noise diagnosed by mechanic as needing a new transfer case based on the noise made under hard acceleration. New transfer case ordered from Porsche late 2018. When I stopped by the dealer to check on status of the order yesterday, I was told it's on indefinite backorder. Are there any alternatives? Does a VW Touareg or Audi Q7 transfer case work exactly the same, and are they equivalent and available? So frustrating