Hey all, I unfortunately blew the head gasket on my 4.0 with 180,000 miles. I'm sure the turbo probably sped up the process of the head gasket failure.. Any way after taking the head off, I checked out everything and all seemed to check out except for the cylinder closest to the front of the jeep, cyl 6 I believe? You can see on the gasket where it started to chew up and let water into the cylinder, although what is alarming to me is every cylinder except the 6th feels smooth to the touch and has the nice glaze that you would expect to have. The area on the cylinder where its the worst is towards the top, on the bottom of the cylinder wall it feels smooth.. If I rub my finger nail along the rough spots I feels like I am actually removing what looks like surface rust and not actual scoring of the cylinder as it did sit for a while before I started the project. I have pictures that will hopefully help explain what I mean. I was wondering if maybe towing it to a machine shop to maybe get the cylinder honed, or even me doing it my self would maybe do the trick.
Thanks in advance, Tony


Here is the 6th cylinder, as you can see somewhat, the "scoring is the worst at the top, towards the bottom you can see where it may not be as bad.




Another angle of the same cylinder.




At the bottom of the gasket you can see where it blew.




And here are the valves of the same cylinder. All others are clean and do not look any near as bad as this..


Sorry for the large pictures, but I hope this will help explain the situation.

 

The cyl in front, closest to the rad, is #1.

Toast.

Time for a rebuild and new bore size.

 

Thanks for the info on the cylinder #s , that cylinders that bad? I'll look into a rebuild kit and see if that's do able for me and my budget.

 

Another question I have is, what caused all the damage was it the water that caused the scoring? Thanks again for the help

 

LS swap =p

 

Yes, water/coolant/impurities caused the scoring.

Looks like coolant got to the oil too.......bearings.


Just an opinion.........but you can put it back together and see how long it runs.

 

BTW, that rust tells me it has leaked for a while.

 

the rust says it sat for awhile before he pulled it apart. take some emery cloth to the cylinder and see if it won't clean it up any. how long did it sit with coolant in the bore?

 

Nothing more than a week at the most.

 

Clean up the bore on that cylinder with some 600 grit wet sand paper and a little wd 40. Try to keep it as clean as possible. Stuff some rags in the bore. See how clean the top of the piston is. Thats from coolant being burned. If the cylinder looks decent after being sanded Id put it together and run it.One question I have was it running anti-freeze or water? I would not hesitate to reassemble and run it if the cylinder does not have any gouges in it.I have seen much worse work out ok.

Ron

 

I am not doubting you at all as you are probably still right about that , but how come this sort of thing doesn't happen with water/meth injection in high performance applications. I read an article where they used water meth and then tore the motor apart and it looked brand new not a spec of carbon in sight, which makes sense in my case with that first cylinder not having as much carbon as the others . I just try to get the rest of that surface rust off to at least where there is no discoloration in the cylinder and go from there.
Thanks to every one for the help so far I'll be working more on it tomorrow and I will have an update as well

 

oh just a week? simply running it would and the rings clean up any rust in the bore. I'd still put something on it like emery cloth to see exactly what damage, if any, is on the cylinder wall. definitely have that head magna-fluxed before reusing it.

 

Yep and my head gasket blowing wasn't involved with heat either it wasn't even hot when it blew, I did have to drive it home about a 10min drive after the fact though with the temp rising to the 230 range, but I would pull over and let it cool down . Most likely causing my damage if that's the case.

 

Looking at the gasket you can see that corrosion has damaged the steel ring. As said before much worse have been put back together with good results.

 

were you making a pull on it when the gasket gave up? I don't see any issues if you say there's no bad pitting in the cyl wall. put a good gasket and head on it, some fresh oil in it and let it eat.