Chris88

Does make sense. I will be changing my plugs soon, so thanks from me as well. I know I'm (we're?) a bit overly concerned, as I wouldn't want to damage these connectors.

itrsteve

This tool rules, I just got mine in today. Thanks for the tip!

Picked mine up from KC Tool Co.

prl

Be careful buying spark plugs off amazon many people have been getting fake ngk plugs (look identical) that have been failing and causing engines to die.... I know these call for Bosch plugs but just a heads up. Sometimes when something’s 1/2 or less the price there’s a reason.

911TurboRules

I just did the plugs on my 2014 GT3. Took maybe an hour leisurely. This thread and the youtube video from Obsessed Garaged helped me out ( ) Thank you to everyone who contributed!

Some notes:
1) the socket size for the GT3 plug is different depending on if it's a 12 point socket or 6 point. It's a 15mm deep 6 point socket and 14mm 12point socket. Strange.
2) 5 of the 6 plugs are easy. The 6th one (driver side towards the front of the car) is tricky because of the Bilstein shock sensor. First unplug the connector to the Bilstein sensor. Then remove the retaining torx screw to the coil pack. Then use a 10mm socket to loosen the nut that holds the retaining bracket for the Bilstein shock. I didn't have to remove the nut. Loosened it enough to move it to pull the coil pack out. Then I used a swivel 14mm socket from Amazon to reach the spark plug and removed it. 14mm spark plug socket ( ).
3) The part for my 991.1 GT3 changed to 999-170-153-91 (as opposed to xx153-90). I confirmed with the Porsche dealer and they told me they sent the right part. The 91 part must supersede the 90 part?

Dealer quoted me $1300 for this job - which for a GT3 is less than an hour for an amateur doing it for the first time. Seems wrong.

GrantG

Hmm, according to Suncoast the 991.1 GT3 uses the plug ending in 90 and the .2 GT3 uses the plug ending in 91:

https://www.suncoastparts.com/produc...917015390.html

https://www.suncoastparts.com/produc...917015391.html

911TurboRules

I ordered my plugs from porscheparts.autohausofpeoria.com. Their website says the same as Suncoast but the guy I talked to at Autohaus Peoria assures me that the 91 is the right part for 991.1 and 991.2 even though the website says 90 is the part for a 991.1 GT3.

911TurboRules

So one possible issue I'm having is it takes a little longer cranking to start the car. Before the spark plug change, I just turn the key and let it go and the key springs back and the engine starts. Now I have to turn the key and keep it turned a few seconds to let it crank more, then it starts. I have the battery on a trickle charger/maintainer. Have you guys noticed this? I have seen this once before in the past on my old Honda.

Thanks in advance!
Paul

GrantG

Mine fires immediately. Not sure what could be responsible for that issue...

Maybe try it with the key turned to the intermediate position for a few seconds before turning to full ignition position to see if that changes anything...

911TurboRules

Thanks for the tip! But appears problem fixed itself. Starts right up now. Maybe takes a few starts.

itrsteve

Just tackled the DIY plug job thanks to this thread. Big thanks!

Few quick notes:
- Anybody who does this without taking off the wheels is a psychopath.
- The Hazet specialty socket posted earlier in this thread is incredible - I got mine from here
- Instead of fumbling with the connector for the PASM stuff, there's a 10mm on a mounting bracket, just loosen that up a bit and you can maneuver it out of the way no problem.

I already had my wheels off and this roughly took 40 minutes with being hyper-cautious.

Did the RS air filters too while I was wrenching around. Not sure how much I saved, but was a fun evening! Thanks RL.

mrhamamg

Spark plug related question...I’m at 5k miles and just had the 2 year done at my P dealer. They didn’t do plugs because they said i only have 5k miles despite it being part of the 2y service. Should I take it back for plugs or what are everyone’s thoughts?

GrantG

I think the manual says something like 2 years or 12k miles, whichever comes first.

Mike in CA

That is true and that's why I did my plugs last time even though the mileage since the previous change was nowhere near 12K miles. But it did get me to wondering if it was overkill and how exactly spark plugs lose function just by sitting in the engine without it being run.

GrantG

Fair question and I don't know the answer to that. But, several .1 GT3 and RS owners have had plug issues even well before the 12k miles, so I don't think the manual's recommendation is overkill at all (with respect to mileage anyway) and may even be too lax.

Mike in CA

As I stated above I did mine myself, even though I had less mileage between changes than you did, just because that's what the warranty manual specified. That said, if the dealer had suggested that a plug change wasn't necessary I probably would have skipped it.