Very helpful and good information! Thanks for posting! Rep point for you..

DC

 

Thanks for posting this! Did you notice that the part number you posted is an updated part number? 99710530372 was the first revision....so hopefully there was some sort of defect and Porsche has since fixed.

I just did an oil change last week...probably 125 miles into just threw my first ever CEL. Hooked up durametric and P0021 and P1640 are front and center. CEL popped up while driving in slow stop and go traffic.

Question...is there something that can be logged/verified with a Cobb to confirm which one of the sensors/actuators is indeed at fault?

 

A regular scanner will tell you which bank is the problematic one.

 

CEL popped up again. Scanned with Cobb AP and then with Durametric. Pulling two different codes. Cobb claims to have fixed the transposing issue....p2100 and p0021 are two very different problems and the cost factor between the two is absurd. How can I confirm the issue?

 

I would go w/the easy one first: replacing the faulty cam actuator selenoid on bank 2. It really is not that hard and you are only looking at a couple hundred dollars...basically, 2 oil changes worth. That could be the issue. If it is, then you are good to go. If it isn't, at least you know what to do next.

 

Ordered the sensor and the o ring seal. Thanks for posting the part numbers

 

Changed actuator yesterday.....reset CEL and nothing yet. The old one was tripping the CEL 30seconds after reset. Going to commute and see if anything pops up. I will also post some pointers on the actuator swap in a stock vehicle.

 

Hopefully, that does it man.
Did you disconnect the battery or did you simply swap the actuator?
Sometimes when you disconnect the battery, the errors take a while to come back since the computer is still re-learning everything.
Fingers crossed for you!

 

Thanks guys. I would not have been able to change this without you guys. Pretty straightforward once I figured easier to pull the harness plastic holder thing towards the back of the car to sneak my extension and socket behind it.

As Tailwag noted...screws can fall out of socket when trying to put them back in. I took some loose leaf paper...folded it once and placed it at the face of the socket. I then jammed the bolt into socket with the paper, thus creating a pressed fit (cut paper around socket)....no more lost bolt when trying to initially thread it into the hole.

 

Cobb sucked here...not sure why the code readout was incorrect on the CEL

 

I just swapped actuator (no battery disconnect), but I used Cobb to reset the CEL and I did notice that in the process the screen at one point says clearing ECM learning, so maybe it resets everything back to square one? 87 miles so far and still in the clear.

 

Bumping this up as I have had the same thing happen. Driving along just fine, hit a bit of stop and go traffic and boom, CEL pops up out of nowhere. The car was driving fine and but for the CEL coming on I would not have known there was an issue. After a nervous drive home, praying that I wasn't doing any damage by driving the last 8 miles to my house, I got it in the garage and used my OBDII scan tool to find the P0021. A few minutes of searching and I found this thread.

I swung my my mechanic's shop (30yrs as a Porsche master tech, formally at a P dealership but running his own shop now) and he confirmed everything that I've read in this thread, specifically by TAILWAG. He said this is a pretty common problem and one he's seen a lot. He said sometimes it can just get stuck and once you clear the CEL it doesn't come back, so he suggested I try that first. If it does come back, he said the next step is to change the oil and swap the actuators to see if the problem switches from one bank to the other, at which point you replace the bad actuator and that usually is the culprit. Of course if that doesn't work, then it is time to pin the cams, which is labor intensive.

I bought the car used and with impeccable service records, but I've only driven it less than 1,000 miles so far. Though I got it from a P dealership, I talked to the previous owner as well, who told me he traded it in on a newer 911. I don't want to believe he's already tried all of these things and got out of the car before he had to do the expensive repair, so I'm hopeful it is just a fluke that this has happened to me now, and I'm extra hopeful that at most all I need is a new actuator and things will be fine. I'm out of warranty, so anything I need to do will come out of my pocket.

 

The labor $ you will spend (if not doing it yourself) of swapping actuators and seeing if the bad actuator switches the code to the other bank is going to eat into money that you can just spend on getting a new actuator to begin with. I have begun to wonder if a failing actuator is ultimately the cause of the spun camshaft in the end (given that actuators do fail).

 

vbb, BTDT, both with having the cam replaced on one side (thankfully under CPO) and then the other side (I put in a new actuator myself) and it hasn't been an issue since.

I bought a fidelity warranty to cover myself in case the other side ever needed a new cam.. Would've been 8K if I wasn't covered by CPO..

 

You're actually right... probably just as cost effective to buy a new actuator for the side that has failed and have that put on (with an oil change as well, because it couldn't hurt) rather than swapping and driving around waiting for the CEL to come back. In fact, now that I've cleared the code, if (and probably when) it pops back up, I'll just get the new acutator installed. That is the better plan. Thanks.

The mechanic seems to think this is the problem by the way... that the actuator just fails after time. I can live with that, though it is annoying nonetheless.

Yeah, there's an ocean of difference between replacing the actuators and having that fix the problem vs. having to do an entire cam job. I don't have a warranty and didn't get one simply because this is a "toy" that I plan to drive maybe 300 or 400 miles a month, max. That said, as with any used and fairly expensive car, you always hope to avoid the doomsday scenario where you get hit with a $5K+ repair bill. In fact, one of the motivating factors in selling my previous 997.2 non-turbo with PDK was that I didn't want to have a failed transmission and end up having to spend $14K on a total replacement. Figured the 997.1TT Mezger is old faithful, right?

Let's just say I'm hoping that the actuator is all I need.