Pulled the head today, look at the head gasket!
Geez! Not sure why, but it looks like the middle layer failed, and blew through a good part of the head gasket. I hope this is the only cause of my severe coolant pressurizing!!
Any ideas of what would have caused this? My theories are detonation on that cylinder, possibly the head not being torqued down enough, or a faulty gasket.
–mark
You’re supposed to be the Neon guy! :mamoru: But I would have to assume it didn’t seal too well considering they fixed the HG issues in 98. I thought about removing the HG shim (middle layer) last week for a couple ponies, good thing I reconsidered.
It was pressurizing the coolant system so bad, I couldn’t keep any coolant in it! I am pretty sure it was from running lean, and it blew out the gasket, maybe a combination of that and not being torqued down enough.
I didn’t install megasquirt on it for the previous owner until late last year, so up until then, it was probably running wicked lean.
how did the HB feel? your gona have to check the block and the head good, with driving around like that often it starts to burn more the the hg
you explained pretty much what it could have been, and with it that bad that is 99% your problem for the coolant
id imagine detonation caused the head to lift and blow out the gasket
just make sure to get it decked before throwing it back on
i’d guess bad torquing/procedure. is that a common lean cylinder on those motors? As with studderin said i’d check the head and block also.
At least the block is cast iron, so its more resiliant, but its still worth checking! I will probably have the machine shop here check the head over, deck it if neccessary, and then check the block over good with a straight edge to check for any problems!
Yeah, cylinder 1 does run the leanest, now that I think about it. It could have been all very lean, and this is the first one to go since it was on the end, or it could have been a bad injector, any number of things. I will get it looked it, I just hope that head is ok! One side of the head gasket was mint, and the other was crappy, so hopefully it didn’t do too much damage. Even if it did, nothing I haven’t already done on these stupid fucking cars, hah.
Some good news is that this combustion chamber on the far right is the one that had the bad head gasket, and it doesn’t have visible black marks to the right of the chamber, so that is the first good sign:
I hope everything turns out OK for you. Doesn’t look too bad.
lol they only fixed them in the 2nd half of 98 
i had a eairly 98 with head gasket problems. i think the production after like july were fixed
Im gonna say it happened because its a Neon, doesn’t that happen to all them?
I think that was only the mid 90’s Neons. I think they fixed that problem in '98-'99.
Nope. Only replaced mine because it has a new top end.
The fact that they fixed them in 98 is not relative here, since its a fully built motor. This is my turbo car, not some daily driver.
Plus the failure for stock Neons was not anything like this failure. It resulted in an oil leak on the exhaust side of the #4 cylinder. Not a lean blow-out on #1.
this is the new neon you picked up??
Correct. I bought it with a bad motor, knowing that I would be fixing it up. I had hoped from day 1 it was a head gasket issue, and not a cracked block or head, and this gives me more hope that my initial diagnosis was correct!
Is that uber ported head alright?
Can’t say for sure yet, but it looks that way. There are no obvious “burn” marks on the head. I will have it looked over, but I think we dodged the bullet here!