Spark Plugs….is this likely a AOS?

First, for those who said changing plugs and coils was easy and quick….bull. They are on the driver’s side, not so much on the passenger. Still have not gotten the electrical connection snapped in on the one closest the rear. Too much rubber sheathing around it and little room to work. But my plugs were dark, more so on the passenger side but the driver’s side plugs were dark too. From what I have read it is probably air filter or AOS . I will change both, the filter myself but will likely have a mechanic do the AOS .

My 09 2.9 wasn't a problem. Can't imagine a .1 would be that different. Its a nice feeling when they are done and she runs smoothly.

Those plugs look fine to me. A tad dark but if the car has higher miles...ehhhhh. I wouldn't say they look oil fouled, so in the absence of other issues I wouldn't suspect AOS issues. You can check if the AOS is working properly by checking crankcase vacuum.

The traditional standard test for reading plugs was to drive at a constant fairly high RPM, kill the engine and read the plugs with almost no low speed or idle time. Prolonged idling can cause a plug to darken up a bit, it will be running at a lower temperature than "at-speed" so it doesn't burn off the carbon as quickly. That said - these look a tad rich, but certainly not awful. As @gubi points out - the AOS test is a simple one, you just need a vacuum gauge hooked to something you can stick in the oil fill port. If there is lots of vacuum - the AOS diaphragm is likely toast.

Kind of have to agree with you, Flyrod. I embarked on changing my plugs and coil packs and while it is certainly doable for a backyard garage mechanic, it is definitely not ‘easy’ or ‘quick’. There is quite a bit of finagling to reach some of the spark plugs , and getting fingers up into tight spaces to wriggle the stubborn boots off the coil packs is challenging. I did one side yesterday, and will tackle the other side later this week as time allows. It would be a dream come true to have access to a lift, as lying on the garage floor is no picnic. Makes me long for the days when a ‘tuneup’ meant popping the hood, easily accessing the plugs, changing the wires, distributor cap, rotor, points and setting the timing. THAT you could do in an hour, minimal swearing and cramped fingers. But hey, that’s the negative side of the mid-engine setup. The great balanced drive makes up for the difficulties in owning and servicing one. The biggest reward is knowing how much I saved over taking it to the dealer. On that subject, anyone out there know what it would cost at the dealershop? Has anyone had that pleasure? I’m curious to know much money I’ve kept in my pocket.

Four years ago I bought my 987.2 and had a prepurchse inspection done at a Porsche dealer. They recommended a “major service” which included oil change, air filter, brake flush and new plugs. It was $2000. I bought a Quickjack for $1300 and the necessary parts to do it myself. I’m sure that $2000 has been adjusted up in the last 4 years. My understanding is that an oil and filter change is over $600 at the dealer.

Thanks for the reply, PorscheGreg. Funny you mention the QuickJacks, I also purchased a set thinking along the same lines. After this plugs/coil pack swap and an oil change they will have paid for themselves, with extra savings in my pocket. Any future work raises their value to me. I thought I had read somewhere that plugs and coils run in the neighborhood of $2500+. The QuickJacks were definitely a major asset compared to floor jacks and jack stands, and I am thankful to have them, although my fantasy garage would have a full-on vehicle lift, enabling me to stand or sit under the vehicle while tinkering, but my wallet isn’t up to that level of comfort. Even with the QuickJacks, at 67 my body takes longer to get into those positions and longer to rebound the next day. All good though, when the job is done and I didn’t hand over my credit card to the dealership.

Follow-up to spark plug /coil pack change: Completed both sides of the engine, second side went better, as expected, once I learned a few easier methods of wrangling in the tight spaces. Plugs seemed okay, minimal carbon, mostly dry with no oil residue. Not sure if they were the original plugs and coils, as I have no service records from previous owners. Attached pics showing the old parts. Looking at the old coils, if anyone can comment if those part numbers are what came in the vehicle when built, and if Porsche used these same Bosch plugs in production. As an aside: while negotiating with the reseller, I sent it out for a PPI to a nearby indie shop with a good reputation. I visited the shop and it seemed to pass muster. Large facility, lots of high end cars, imports only, clean, well organized, if that is any clear indication of a professionally run establishment. On the report, everything checked out with a thumbs up, although there was a notation that they noticed cracks in the coils, and recommended replacement in the future should I complete the sale. I had read that the coils were prone to cracking, and it was quite common. Not sure if it can be discerned from the pics, but there were no signs of cracks in the coil packs. They were absolutely intact. I guess they figured I would return to them one day for replacement, but they figured wrong as I did them myself. Glad they are done, but overall not the hardest job, but not the easiest. Time and patience. I’d deem it a 6/10 difficulty rating for the DIY’er.

Really makes me want to get a quickjack , but I don't have the budget for it right now. I just did the same job 2 weeks ago, but on jack stands. I did it in one day, but it was a brutally long day. Did your plugs come out easily, or were they seized like mine? Looking at your plugs, they look better than mine did. Did you also stick a camera into the cylinders? And how many miles on your car? You can look at my thread for comparison https://www.planet-9.com/threads/sparkplug-change-and-lots-of-carbon-build-up-987-2-2-9.256526

I know that feeling, especially now that the days are short. I was packing away the tools and quickjack when I realized it was pitch dark outside. Also because when we work on our own cars, we take our time, check tightness not once but twice,it everything back the way we found it. Always a good feeling. My plugs came out easily. Day one, doing the passenger side I had warmed the car up while gathering tools, etc. so that by the time I started it was barely warm. Day two, I did it cold but felt no differenc in extracting the plugs. I did not stick a camera in the cylinders, although I do have a cheap Amazon borescope, but using it is such a hassle I didn’t bother. Get what you pay for. My ‘08 just passed 50k. Took it out today after a washing and it never fails to please.