I’m not even sure some of the same old folks I use to know around here are still in it, but I’ve come back for some questions on the “ol turd”. Aka my dreaded 7.3 I’ve had for quite a few years and had the engine out for the fourth time now. I could go on and on and trying to catch up but I’ll just get to the point. After having this engine in this truck rebuilt 2 times I find myself once again tearing it apart due to pressure from a cylinder in the coolant. Long story short the truck still ran great and I honestly believe a set of head gaskets can get it back going but I found something the second engine builder had mentioned and it’s got me thinking. You see the first engine overhaul failure was said to be due to the shop not decking the block. I don’t know much about actually rebuilding motors, more or less just a weekend wrenched. But the head gasket had slipped, I’m guessing when torquing down the head and the rebuild lasted about 50k miles or so before finally burning that portion of sealing ring around the cylinder. Anyhow the shop said we need to deck the head to get everything true so this doesn’t happen again, fair enough. Well this rebuild has been flawless since prolly 2012 and I’m guessing everybit of 100k miles. Well a couple weeks ago I got hot headed and let her eat on the interstate and ran the ol 7.3 prolly beyond what an average dually with 4.30 gears and 33” tires should do and I saw the egts around 1600 and prolly should have backed out but hey, I was tryin to prove a point! Well unlike some of you may think nothing happened, she just went till I gave up! But two days later we went to eat during lunch and the dreaded starter stall happened. I knew what it was. Water in the cylinder. Well at this point there were 6 of us trying to get back to work, so after a few minutes I hit the key again. Luckily it cranked. Puffed a cloud of white smoke and was running back to normal. Well when we got back to work a coworker said hey your leaking coolant. At this point I knew what was up, so popped the hood and loosened the degas bottle cap. Yup, lots of pressure. So we cranked the truck to see if we could see any bubbles and we couldn’t but we did notice the level in the degas bottle would rise and then fall, rise, then fall. Ok now I know I’ve got a head issue. Well I drove it home with the degas cap lose and it ran just as it should. No overheat, no smoke/steam out the exhaust. So I figured there wouldn’t be much wrong. Now back to the point. After disassembling the engine and removing the heads, I was clearing the cylinders of oil and I noticed the pistons would rise above the block decking. So I took out a straight edge and some feeler gauges and the pistons rise right at .030 above the block. I measured the crush in the old gasket and got around .070 thou on the head gasket ring. Does this seem about right? I’m hoping I can just clean the heads and the block and replace the head gaskets with some oem ford gaskets. Now if your wondering where the water was coming from, I did find the number 2 cylinder head bolts didn’t seem to be torqued all that tight, in fact I hardly had to put out to break em lose where as the rest took some extra effort. Also around the #2 there was build up almost like rust behind the compression ring. If you ran a straight edge over it it was built up pretty high but removes with a razor like it is a softer material. I figured there has to be a spec for that gap. I seem to even remember something about a thicker head gasket but that may have just been me questioning what would happen to the compression when you deck the block. Man I hope someone finds there way through my story and has an answer! And for any ol friends in here reach out and say hello!!

 

If you got her as hot as you make it sound, at a minimum I would probably take the heads to a reputable machine shop to be sure they didn't get warped or cracked. It would suck even more to get it all back together only to find out you get to do it over again.

 

Again I did what I did to myself!

 

Someone refresh my mind how to post pictures and videos with apple device

 

If "to err is human" then I'm likely the most human sum-bich on the planet.

 

Good to see ya! Too bad it's under these circumstances.

There's more to this than repeated head gasket failures. That's rare as hen's teeth to begin with.

 

Welcome back!
I'm not a rebuilder myself, left that to the machine shops. With that said, if you've had to redo this same engine assembly for the third time, I would chuck the whole thing and get a completely different assembly. Something is foundationally wrong with the block/heads somewhere, and I wouldn't trust it again.

 

Well after further digging I’m pretty sure I’m gonna need a new block. My best guess is some sort of electrolysis took place and eroded a section between the block and sleeve. So if anyone around sw Louisiana or east Texas has a rebuildable block I could use it.

 

Looking back this was the same cylinder that had failed after the first rebuild.

 

Yeah, you now have a nice boat anchor for your fishing boat.

 

Crawfish trap?