Smashed spark plug in 90 N/T...

[Tallen]

90 N/T 2.0. This sounds like a head going bad, but maybe its something else. When we first got the car, it was idling bad. We changed the plugs/wires. The #3 was smashed (not damaged, just had the tip smashed onto the electrode). We thought cool, thats why its running shitty. But at the same time, I only knew one cause for something like this. A few days later it was idling bad again. This time #1 was smashed. Its back to running OK again after we bent the plug back to normal. Should we change the head right away or is this a slow progress. I will be reuilding a head I have over the next week, is it ok for her to drive the car? Could it somehow be somethign else causing this? Detonation?

 

[spyder dst]

stop!! sounds like you have the wrong plugs and that the tip is sticking to far into the head causeing the piston to hit the plug!
running the engine like this could punch a hole into the piston face, then you are looking at real problems.

 

[qwall]

yea what plugs are you using?

 

[Tallen]

Hrmm I never thought to ask if it was wrong plugs. I'll make em get a new NGK set. What NGK plug do N/T 2.0' use? 5es?

 

[spyder dst]

according to the ngk site a 90 eclipse nt 2.0 uses BPR6ES-11

 

[fivestardsm]

Might Not be the wrong plug!! I had the same thing happen on my 92 AWD, and the same plug even, I haven't torn it down yet, But im pretty sure that the ring land came apart on the #3 piston. I have seen it on other engines. Do a compression test, but it might still be good, mine was. When mine happened, I pulled into a friend's yard, and 15 min. later went to start the car and it sounded like something ran throught the motor. Well i pulled all the plugs and the #3 was demolished. I put another plug in, and it ran fine for another 15. so I changed it a again to get it home, and it didn't do it again. I checked the compression, and it was 150-160 across. I parked it and went back to the 90 AWD! Some day i'll pull the head and see.

Steve.

 

[Tallen]

Yea its got the right plugs...damn.
So this sounds more bottom end related? Threw a rod bearing? I think we'll just pull the head and oil pan after finals are over.
Compression is great across the board.