Recently had the porcelain get destroyed during a WOT pull. these were brand new too. Where do the majority of you purchase spark plugs? I order everything online but spark plugs I try to get them in store fearing that they would be mishandled at one point during shipment. Well that didn't seem to matter since the ones I got were from the store. O'Reillys surprisingly stocks the NGK plugs we can use in our Evo 9. Anyone with a similar experience purchasing plugs from stores like O'Reillys? I'm going to now purchase the Mitsubishi packaged NGK plugs and I will get those from the dealership. This was unfortunately the 2nd time that it has happened to me, first time my valve was not so lucky. This time around I may have been lucky. Car fires up and drives fine. The idle is slightly off from before but I have yet to throw in the brand new plugs. I hope people can chime in, I don't know why this has happened to me twice if it's something I'm doing wrong then I need to correct it. Car has a built motor running lots of boost on e85 so I'm not talking about this happening on stock turbo on 91.

 

Had an owner write to this forum a few months ago saying the cover over the spark plug gallery somehow got broken. As far back as I can remember, people occasionally encountered plugs that leak up through the porcelain. Sometimes the plug wire blows off. Broken porcelain, I dunno, but I imagine these things are all robot made and if the robot is out of whack there could be more than a few bad plugs around.

 

How tight do you tighten em down when you install them?
I've never had an issue with NGK. I did find a bad plug on someone else's Evo, but it was a Motorcraft, Autolite, or some other brand. The insulator at the bottom was sliding up and down on the center electrode.

 

If this is the second time it's happened I wouldn't point fingers at the spark plugs.

You state you are running E85 with "lots of boost". I would check the fueling, tune, etc.

Spark plugs usually only blow up from det, heat, foreign matter or extreme pressure. I highly recommend getting to the bottom of the cause or it will keep happening. Have you been logging during the failures?

I feel your pain as I recently had a motor taken out from a spark plug failure. Mine was from going lean from fuel starvation on track.

 

Wow. What are your afr during full boost

 

If you where asking me...

11.5-11.8

At time of failure 12.7 then 15.2.

 

Thats crazy man. Hope the pieces blew out of valves in time.

So what is your prediction? Failed injector?

 

No, the motor is done. 0% in Cyl 4 and 3 is hurt as well. Most likely melted, stuck or damaged valves. I still haven't pulled the head yet.



I boroscoped the cylinder and the piston is nicked and there is shrapnel from the plug all over so it's rebuild time.



Fuel starvation from a very left turn centric track, even the surge tank didn't save me. I'm overbuilding the fuel system and warning systems this next go around...

 

If cylinder walls seem ok can you/will you reuse block? Or will the pits of the piston domes cause a knock point?

 

I'm hoping the walls are fine with just a hone. We'll see soon enough.

I'm taking this as a chance to build the motor so the oem internals are going buh bye and I'm going to build everything for 8500rpm. I'm also putting a PT5858 in the car.

 

Razor lab, sorry to see what happened to your evo, I already went through a motor, I don't want to experience that again.

I'm definitely concerned about this and want to get to the bottom of it. The first time it happened, it may have been fueling issues since my injectors were maxed out at the time. Stupid move on my part. Fast forward, redid the head, installed ID2000s. Ran the car with no issues, probably more boost than before on the new tune and on e85 for I'd say more than a year. As part of my frequent maintenance, I swapped my plugs with new ones (this time around) less than 200 miles and only a handful of pulls and this happened. My AFR was not lean, no sign of knock during the pulls. I just got a tactrix and happened to log during my pulls but not sure if it will tell me what I need to know. Car was still running, just a small weird misfire during idle. Drives decent but I can tell there's still something wrong with my car. Here are some pics of what blew





I have yet to do a compression and leak down and I'm also going to swap all 4 new plugs

 

My car still runs as well, just on 3 cyl. I actually managed to limp it around the whole 3 mile track to get it back into the pits without a tow.

Do a compression and leak down test. It will tell you a good amount. Also think of picking up a boroscope so you can check your piston tops and cylinder walls. You can get a super cheap USB one off Amazon for under $20. That is what I used and the quality is actually surprisingly better than the crazy expensive snap-on versions.

 

Which boroscope did you pick up? DBPower or Crenova?

 

Broken porcelain on the business end and speckle pattern is detonation.

 

I work for hyundai and our turbo motors experience this and is always catastrophic.

Im starting to see alot of 4b11 cases as well.