Kealinstillz

Hey, everyone, I'll try and make this as short and sweet as possible. First let's start off by saying, I had just recently gotten my car back from getting some work done(clutch, injectors, tune E85/93 car made roughly 420whp and 390tq on E85). First time driving my car in 7-8 months(in the Navy and car is located in my home state and I'm not currently there). Heading home from the airport barely get into boost and I hear this awful noise. Pull over on the interstate and pop the hood to find out that it decided it wanted to shoot the plug back out of the top. Get the car towed home and the next day figured out that the threads were shot, got in contact with a mechanic friend and he told me what he thinks had happened and it makes sense to me.
In the picture of the 4 plugs the one missing the electrode the crush ring wasn't "crushed" like the rest of them. So I'm guessing that after some time it just wiggled its way enough to where enough force would eject it out. I have a new head on its way that is going to be slightly built just not ported and it'll be on stock valves. My question for you all is after I get this head in and installed if you think I will have any more issues with it. I'm obviously hoping I won't run into any more issues with this but who knows maybe something else has been going on that others can think of? Especially with these spark plugs. Which leads me to the next question of, what would cause the electrode for the thing to just break off? I didn't see any damage down inside the cylinder with this little telescopic camera, so I'm hoping it got sucked out of the exhaust. This has happened twice now but I can't remember which exact cylinders it happened to the first time.
Thank you, everyone, any help is very much appreciated!!

barneyb

Electrodes break due to detonation.

4b11slayer

Damn ive never seen a plug blow out of the threads. Probably left loose.

Pal215

iTrader: (12)

I've never seen a spark plug blow out of it's hole so hard that it takes the coil pack and a chunk of the valve cover with it. Tighten spark plugs to at least 18 ft lbs. A lot of people leave their plugs too loose because they are afraid of stripping the threads in the cylinder head and that bottom "crush ring" never get's crushed. Use a torque wrench and you'll never have to guess.

For new plugs, I usually tighten them using only wrist strength until I feel that the ring has been crushed. Then I torque to spec. However, as others have mentioned, I would recheck the tune as this looks like knock damage.

LetsGetThisDone

iTrader: (1)

Electrode could have broken off because the plug got banged around when it came out. Looks like none of the plugs were properly torqued. They should be 18-20ftlbs. They can get blown out when they're left loos like that, Crazy it took out the valve cover too.