My S2 started misfiring really bad. The plug on the top is an old AGP901C, the other two are AGPS071C which are currently on the car.


What caused that wear on the ground electrodes? They barely have 20k kms on them. I reinstalled the old 901C plugs and the car is running fine. Also what new plugs do you suggest? The car is basically stock.

 

There as been a drop in quality on the 701's or a bad batch a lot over here have stopped using them .

 

20,000 Kms !!!!

 

That is a lot for Motorcraft...mine usually doesn't last that long..

 

Too many? The one at the top of the pic probably is as old as the car, and it had 57k kms when I bought it.

 

didn't see the mileage ::

 

071c work fine at 2.5bar !! iff your running standard boost or a bit over up to about 22psi just use some normal bcpr8es ngkr job done .
the top plug looks ok in colour , the bottom one looks wet with oil ! and rich so does the 2nd one down valve guides or stem seals maybe :O

 

12427.4 miles is quite a lot. Personally if the car is a daily driver, I'd be changing plugs every 3 months.

I'm sure Hanyes manual says to change plugs every 3,000 miles on RS turbos.

bcpr8es NGK plugs for me, for the price of plugs is a no brainer to swap for new plugs regularly, Wire wheeling the plugs using a drill bit during 'Sunday' maintenance never hurts either.