Just to clarify the confusion (or make people more confused): the service manual indicates initial tightening for spark plugs to be 24 ft.lb.; the second tightening is 19 ft.lb.

 

This new plugs 24
old plugs 19

 

It's not mentioned on the first post, but the E-torx that attach the heat shield to the engine should be torqued to 7.5 ft.lb.
Now, what about the torque values of the ignition coils to the engine? Ignition coil to cylinder head cover is also 7.5 ft.lb.

 

Huh? What do you mean the thread is different? The thread pitch on the spark plug? I don't see why it matters if they are using the same spark plug for the 981 and the 991. The thread pitch is probably the same for all spark plugs for Porsche, hell the thread pitch could be the same for all spark plugs in general.

 

Thread size is different. 991 GT3 thread is smaller than most 981s.

 

That's interesting. I always ordered from Suncoast and never had issues when I had mine.

 

Anyone have the part number for 991.1 GT3 serpentine belt
and brake fluid?

 

Serpentine belt is 0PB-903-137-E. This part number is updated from the prior 9A1-102-217-00.

 

Thank You

 

Ordered plugs for my 991.2 recently and the plugs that Suncoast shipped were 999-170-237-90. Upon further research, it seems that 999-170-237-90 has replaced 999-170-153-91

https://parts.porschechandler.com/oe...MC0xNTMtOTE%3D

By the way, I had a 14mm, 12 point BMW spark plug socket and it fit perfectly on these plugs. Only $7 from FCP Euro:
https://www.fcpeuro.com/products/12-...ug-socket-14mm

 

I have just completed the spark plug change on my 991GT3 Touring. It's almost comical how easy it is compared to the same job on 718 4.0 engine.

If I didn't have my NutCracker at hand, perhaps the only nuisance would be the centerlock wheel removal and installation.

The level sensor on drivers side (I believe previously mentioned in this thread) does interfere slightly with the first coil from the left, but it is perfectly possible to work around it without the need to remove it.