I have a 94 4.0 OHV and I think my head gaskets are on the way out or I have a cracked head my coolant gauge will go from 1/4 to 3/4 every couple minutes while driving. I am wondering what torque sequence to use for the head bolts and the procedure for installing the heads and lower intake. I already have the lower intake off to do the gaskets and I figure I should just do the head gasket while I’m in there.

 

That reads more like a clogged heater core, not expensive or hard to change in 1994
Heater core is the water pump bypass, if flow is limited it will cause random fluctuations on temp gauge
But no over heating, i.e. to HOT, and no boil over in Overflow Tank
Hows the heat in the cab?

Blown head gasket or cracked head will cause over heating, doesn't go back down, and full or overflowing Overflow tank
You can do a Glove Test, its free
Get a latex glove or balloon or even a condom, lol
A ziptie or rubber band
Cold engine
Pull off rad cap, pull off overflow tank hose from rad cap opening
Plug overflow tank port on rad cap opening, vacuum cap, putty, gum, ??
Put glove over rad cap opening, seal it with ziptie or rubber band

Unplug 4 wire connector on coil pack, you want a No Start
Crank engine over and watch the glove
If you have a cylinder leak into cooling system the glove will bounce, repeatedly, and steadily each time leaking cylinder is on compression stroke
If it just lays there then no leak, for sure

If it bounces then remove one spark plug at a time, and crank engine over
When glove stops bouncing the last spark plug removed was from the leaking cylinder, put it back in to confirm, this can be helpful when looking for the fault after disassembly

 

Ron thanks again for your knowledge. I have good heat from the vents. I ordered a new radiator and thermostat to replace with the intake gaskets. My cooling system is pretty rusty inside. If I pull the radiator cap off with the engine running it will have coolant overflow out the radiator it will do it every couple minutes. Do you think this could be something of concern?

 

Buy a 3/4" plastic or metal hose coupler

Remove both heater hoses at the firewall and put the coupler in between, i.e. bypass heater core

No heat in cab of course
See if that stops the overflowing and random fluctuations in temp, if so replace heater core, 4 bolts/screws in cab, not hard at all to swap out

Rad cap will overflow after 3 minutes or so of warm up, that is just the coolant expanding as it heats up, its what causes pressure in cooling system
Blown head gasket or cracked head should start overflowing rad on Cold start, no warm up needed


Cylinders have 150psi when cranking, over 900psi when firing
Blown head gasket or cracked head allows some of that pressure to escape into the cooling system, the water jackets around cylinders and in the head
This "air" displaces coolant in the engine, forces it out of rad cap opening if rad cap is off
Leak doesn't come and go, its there all the time
You should also see Bubbles in rad cap opening, the "air" that's being injected from the leak

This "air" is actually exhaust if engine is running
There is a test called Block Test
It tests coolant for signs of exhaust chemicals
It can give false positives so not a definitive test, I prefer Glove test myself

 

I’ve got it all back together and now cylinder 4 and 5 have a misfire. I replaced the coil and did plugs on 4 5 6. Cylinder 4 had no spark with the old coil. I did the glove test and it did not move with engine running and engine cold not running.


Edit I had the 4 and 5 plug wires in the wrong spot on the coil

 

Glad you got it fixed

Thanks for posting the update