1989CamaroRs

my 79 Jeep Cj7 has a 258 (I6), anyway my question is if a motor has an internal crack in the head or block will there always be coolant in the oil. The engine overheats(pretty quickly), I replaced the thermostat, and cleaned all the gauge wiring today and it still overheats tommorow Im going to replace the water pump. It also has low oil pressure, i dont have a tach but at idle its like 10 psi, then moving it may hit 20-25 psi. I also check all the connections for the gauge and im going to replace the oil pump. So anyway does this sound like a cracked block and/or head?

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-Stock Tbi 305 with a lot of damn miles
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79 Jeep Cj7

[This message has been edited by 1989CamaroRs (edited January 30, 2001).]

1989CamaroRs

btw i belive it has 166000 miles, who knows though the odometer roles over at 100k maybe its 2 or 3. Im just guessing its rolled over once because, the body isnt in all the bad of shape

Russ-So Cal

You probably won't get oil in the water, but if you have a cracked head or block, or blown head gasket, you will probably have oil in the water, but not necessarily.
The best test is to get a block test kit.
It has a chemical in it the checks for combustion gasses in the coolant. Even if you do find combustion gasses in the coolant, it doesn't mean that the head or block is cracked. It might be just a blown head gasket.

1989CamaroRs

so could a blown head gasket result in low oil pressure or overheating?

Engineboy

As far as the overheating...

Hows the fan clutch??

Does it overheat in traffic or all the time??

Does it cool down going down the highway??

What shape is the radiator in. (blockage inside, bird feathers outside, Etc.)

As far as oil pressure...

I've seen quite a few with low oil pressure with that many miles on them.

Try putting a manual gauge on it and see what it really is, could just be a bad sending unit or it could just be old age.

Keep in mind that an engine that is running really hot will have lower oil pressure than one running at a normal operating temp.

I think these 2 problems aren't related.

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ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R

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