Is it a cracked head?

[Hossexplorer]

Hey everyone, I need your opinion..

My 93 xlt started running rough like it needed a tune up last week so I had planned on doing one, but later that day while on the highway, the temp got up to the "O" on the temp gauge so I pulled over to check things and it was low on coolant but had not leaked any on the ground. The next day I filled the coolant back up and drove 5 miles and it lost 1 gallon of coolant! There is no coolant in the oil and is not leaking a drop anywhere.

I did a compression check and all cylinders where right at 150psi..

Also in the last year I have replaced the water pump, radiator fan/clutch, radiator, thermostat, temp sensor, and heater core.

Does this sound like common syptoms of a cracked head on the 4.0?
Any input is much appreciated!

 

[ricco750]

It could very well be that your lower intake manifold bolts are loose...a common issue with Gen I's.

 

[Hossexplorer]

Update:

I pulled the lower intake off and coolant had been leaking into the engine. The person I bought my Ex from had rebuilt the engine 5 years ago, but there was no RTV around the water ports as the book calls for. I put new gaskets and cleaned everything very well before I put it back together. I also installed new platnum plugs and spark plug wires. So far the coolant loss is taken care of but, it still runs like it is missing on a cylinder!

Also, the exhaust has a slight blue tint like oil until it gets warmed up, but the engine has never burned a drop of oil before this. All maintanence has been kept up well and compression is good.

What else am I missing? Please help! I'm supposed to be going on a 400+mile fishing trip this friday lol

 

[wantdeath]

my guess would be all the water that got in the oil may have done some damage to the rings. that would explain the blue smoke. cold pistons are slightly smaller than warm ones. they expand a little bit when they warm up which would seal the oil in slightly better and if it is enough oil burning it could run bad. the compression rings and the oil seal ring can wear differently.

 

[rickybobby]

verify the firing order 1st, then check for vacuum leaks and unplugged connectors