This is what I'm talking about. It may not be a crank sensor in your case... maybe a cam position sensor or some combination of faults, but this kind of diagnosis is real. Not "could be lifters".

 

Thanks for all the input. Shop is closed now. I think what I'm gonna do is get it from him either tomorrow (if they're open) or Monday. If they've changed the oil already - i'll just change it back and make a decision on a go-to mechanic. I'll keep you updated.

Clarifications....

** car currently has fresh 0-40 oil in it - changed it two weeks back.
** i'm not sure what software/diagnostic tools this shop has
** my preferred mechanic is the one who doesn't have 997 software

 

Misfires on multiple cylinders could also be the MAF. What kind of air intake are you running - stock airbox with stock filter or an aftermarket one with an oiled filter, like a K&N (EVOMS, Fabspeed, K&N, etc). These types of filters are often overoiled and over time deposit the filter oil onto the MAF sensor. If the MAF hasn't been cleaned I'd start with that simple and inexpensive procedure first before moving onto the more complicated and more expensive procedures. The others here are right though, sounds like you need a mechanic that has the right experience and tools.

 

It looks like I spoke too soon. I started the car up today and it registered a cell.

Current Fault Codes

P0300:
Misfiring checksum error

P0301:
Misfiring cylinder 1

P0303:
Misfiring cylinder 3

P0305:
Misfiring cylinder 5

Looks like it's back to the drawing board. I'll probably replace the cam position sensors next since that was what the Porsche dealership recommended.

 

Sorry for you, but good to know - thanks! I have yet to pick up my car or hear anything more about it due to the holiday weekend. Should know something today.

 

Well at least I know if I lose my job again I can always become a P-Car mechanic... or at least a service writer

 

Since the misfires are all on one bank, maybe one of the two O2 sensors for that bank are bad. There could also be a vacuum leak somewhere on that bank. Just a couple thoughts.

 

Update:

Car is back. 30w oil is in there now. I'm going to change it out this weekend. I agree with what several of you have said, "may not hurt, but I wouldn't want to test the theory with my engine."

Error codes:
P0300 Random/Multiple Cylinder Misfire Detected
P0301 - Cylinder 1 Misfire
P0304 - Cylinder 4 Misfire
P0306 - Cylinder 6 Misfire

Overall, not satisfied with the entire transaction. I can't say for sure the guy doesn't know what he's doing, but I don't have warm fuzzies by any means. Will be continuing search for new shop.

Thanks for the responses on this.

 

So much for the "all on one bank" theory. Could still be bad or oily MAF (if running an aftermarket air intake) now that there are misfires on both banks.

 

Stock intake and I cleaned the MAF a year(?) ago??? Not sure if that's long enough to get dirty "enough", but I could give it another shot.

 

Mulva get the car to a dealer. This is silly and possibly dangerous to your cars health imo.

 

UPDATE: Changed the oil back to Mobil1 0-40 last night. Total of 50 miles driven with the 0-30 (not greater than 4k RPM). No noticeable issues with motor, but will keep my eye on it.

Thanks again for the input - your opinions persuaded me to not rely solely on that mechanic's advice.