Blew my head gasket...again...

[Jeep88Comanche]

So I went and replaced my head gasket and cleaned all the build up.. sparks are good, injectors are good, distributor good, vacuum good. It cranks and it wants start but alas it does not. I've also check fuel pump ballast resistor. At TDC. I'm just baffled.

 

Base 1988 4.0 I6 4wd standard 

Thank you in advance folks! 

[Jeep88Comanche]

Bottom of cylinder head

[gogmorgo]

Looks like a crack in the head to me. Likely means there’s some bad warping even if it isn’t in a critical spot for keeping combustion or coolant in the correct places. 

Might want to have a machine shop check it out, but you might also need to get another head. 

 

Spark, air, fuel. Something’s missing or at the wrong time if it ran before but doesn’t now. I’ve had issues with getting a distributor one tooth off after reinstalling it if you did pull it. 

[Jeep88Comanche]

I've triple checked all wiring and grounds anything I pulled I made sure I put back. Is it possible it hydro locked? I've read about it but never seen it. 

[Pete M]

can you rotate the crank manually?  if it's hydro-ed, it most definitely won't.

[Jeep88Comanche]

Yes I can rotate manually, so that's out the window. I'm gonna pull the injectors and test them. I cleaned them when I had to take it apart. Maybe I missed something. 

[SoCalManche]

15 hours ago, Jeep88Comanche said:

So I went and replaced my head gasket and cleaned all the build up.. sparks are good, injectors are good, distributor good, vacuum good. It cranks and it wants start but alas it does not. I've also check fuel pump ballast resistor. At TDC. I'm just baffled.

 

Base 1988 4.0 I6 4wd standard 

Thank you in advance folks! 

Damn, where did the rest of the gasket go between the cylinders?

 

 

 

 

 

15 hours ago, Jeep88Comanche said:

Bottom of cylinder head

Yeah, looks like a crack to me. I just went through a head gasket ordeal on a Jeep 2.5L engine and I had some pitting between the cylinders on the block mating surface. I checked the entire deck for flatness to make sure it was within tolerance and it sure was. Put her back together with a Fel-Pro gasket and she is running strong! Good luck on your head... 

[Jeep88Comanche]

Back again.... Sorry for the delay. So I had it sitting for. A couple days and then went out today and it fired up. Its a rough start. But progress. I think it just needed it's own "me" time lol. I'll be checking all specs and wiring and then I'll be right as rain. I'll look into getting a new head as well. Smh. Thanks again folks! 

[AZJeff]

With that crack in the head, there is NO WAY that gasket is going to last for any length of time.  This will happen for two reasons:

 

1.   the portions of the head adjacent to the crack are going to move independently of each other.  That will cause gasket damage.

2.  once the coolant is hot, and under pressure, it will start exerting a new additional force of the gasket in a direction other than normal, and that will accelerate gasket failure.

 

That head is junk and needs to be replaced.  Unless, of course, you want to get REALLY good at changing head gaskets on a regular basis.