'98 HO overheat/won't start... possible problems?

[ryno56]

My donor XJ ('98 4.0 AX-15/NP231) that i got for cheap 'cuase the PO said it needed a new engine, cranks but doesn't run. The story was that it overheated... needs rebuilding.

 

My question is, what is the most likely culprit? Warped/cracked head? Blown head gasket? something worse? I haven't drained fluids or taken anything apart on the engine because I bought it for the trans/t-case and all the other goodies for my MJ. Oil is full and looks clean, coolant overflow bottle is full and a bit dark in color with a rainbowy film on top of the coolant. Rad is low, ie: dry up at the cap/neck. If it's not that big of a fix I might do an HO swap with it down the road. I already stole the drivetrain so I couldn't start it if I wanted to.

 

Any ideas?

[89JeepMJ]

Well if it cranks but doesnt run it could be a crank shaft sensor thats only one of the things it could be. not getting like your fuel pump etc. but ya my crankshaft sensor went on my MJ and it did the same thing.

[jimoshel]

Try doing basic troubleshooting. Check for spark. Check for fuel. Go from there.

[Geonovast]

If the top of the coolant is rainbowy, there's oil in it.

[ryno56]

If the top of the coolant is rainbowy, there's oil in it.

I figured. I can't do any trouble shooting now, as I've taken the tranny off (no cps). I'll probably just pull the head and have a look.

 

Thanks.