Just replaced my plugs at 47k miles. Here are the original daily driving, sitting in rush hour, autocross, and multiple track day plugs:



Seems to be fine by my standards. Anyone see anything suspicious?

 

Had the electrode break off on plug on cylinder 1 @ 17k.
Low compression found in cylinder 1.
Damage to exhaust valve which was harped into valve seat.

Coming a week after the AYC pump replacement, which was after the CMC recall and ecu recall, this car is spending a lot of it's life at the dealer...

You'd think they would have this problems figured this late into the production cycle....

My old STI was unbreakable by comparison....

 

You got lucky with your old STI then Those motors pop left and right.

But yes, you have had some issues for sure, it happens. Just be glad the dealer is taking care of them.

 

i had problem when i m under wot in 3rd gear. i hear a loud bang noise and saw cel flashing twice. the cel didnt stayed on. i pulled the car off the road and restart it. it is acting like misfiring at ignition, idle and even slow drive. it also hesitate to accellarate when i try to go on freeway. any idea?
also, i can hear pop noise every 1-2seconds at idle

 

Yea, pull out your spark plugs and inspect them; replace as necessary

 

so all you need is the spark plug? is any other thing can cause this happend?

 

Could be other problems. I personally wouldn't drive it if it's as bad as you describe. Easiest thing to check first is plug problems. Pull them and inspect them, if no problem there, you could have other issues.

 

its lucky that i bought a spare set of plugs last week and will arrive today. if it ended up not the plugs problem. what should my next step be? my car doesn throw any code so i had no idea what to look for. but even though i can still tell its acting abnormal

 

After reading this, I checked my spark plugs and it all looks good. I could probably change them out at 60,000 miles or sooner.

 

Any experience with the Autolite XP5701 plugs?????

Got a set on order through work and will see once they get here.

Chris

 

here's an interesting thing that NGK just put out

http://www.ngk-sparkplugs.jp/english...ake/index.html

 

Does anyone think they actually got knock-offs? If those were the ones that have been failing that would be a huge discovery...I still have the one that failed in my car on my workbench, I'll have to give it a look.

 

I'm going to say likely not. A lot of the failed plugs were the stock factory installed plugs. I personally only purchased my replacement plugs from Don Herring Mitsubishi's parts department or MAP. I would NOT buy something like this from an eBay vendor, and probably not Amazon either...just in case.

 

For the people that have had catastrophic failures, how are you going about engine replacement? Is this something that would be covered under warranty, dealer or aftermarket?

I recently purchased a 2012 EVO X MR with 28,XXX miles on it. I changed the plugs out at just under 30,000 (two days ago). Cyl #4 plug had a bent ground strap and broken porcelain. I can't find any markings on the strap to tell if there was contact inside the cylinder. The car drove fine before that, with only a small miss at idle every now and then. I have no idea how long the car has been running like that. The new plugs smoothed out the idle and it still runs like a champ. I'm going to do a compression/leak down test on it this week and hope nothing serious is going on.

 

Can this be a possible symptom for a slight lag when trying to rapidly increase acceleration? Other spark plugs trying to compensate for another? My sparks look good but again looks can be deceiving. Having a slight lag when attempting to rapidly accelerate at around 3k-4k(only when i go from halfway pressing the gas pedal to full throttle). Any thoughts?