I'm sure this topic has probably been covered in the past.

The cars has 10,266 miles. I tried getting into boost last night and the car started sputtering and would not boost. At idle, it would missifire. I had a suspicion that somethng might be wrong with the spark plugs and started taking the coils and plugs out. Sure enough, pulled plug #3 and found this:

 

Did you get the ground out?

 

Same thing happend to me on my 2012 GSR with 4k Miles. To say the least I was pissed. Is there an aftermarket spark plug that is better than the OEM ones?

 

I did not

I'm hoping that it went out the exhaust valve without damaging anything.

I will be doing a compression test and will also be going to a shop to get a videoscope in the block to make sure the piston, walls, and valves are not damaged.

From my research, the 08-10 Evo X's use a different plug than the 11+.

NGK ILKR8E6 (2008-10 models)
NGK DILKR8B6 (2011+ models)

I ordered a set of ILKR8E6 from O'Reilly. You can get them cheaper online, but I needed them the same day so I had to pay $80 + tax for all four plugs.

 

You can get a set from the dealership for about $55.

 

https://www.evolutionm.net/forums/ev...-failures.html

 

It happened to my friends evo x running a cosworth engine 2 weeks ago, damaged the head and valve. He mentioned that previously he was running HKS plugs with no issues apart from cost.

 

Im curious if the HKS plugs are better from OEM. Everyone seems to just keep using the OEM ones regardless if they keep having failures.

 

Hmm.. That's weird because the stealership told me $100.

 

Also curious if the HKS plugs are worth the higher cost.

 

$54 from my dealership.
Don Herring Mitsubishi - Irving, TX
DonMitsu is his screen name on here; he is an EvoM sponsor.

 

I couldn't say but I know he is switching back to HKS once his car is back on the road, once bitten and twice shy and all that.