New head or fine till i rebuild?

[Jerlaine]

Ok so i bought this 93 Explorer originally to fix it and sell it for more so i can buy a Ranger. I ended up using it for a bit and the driver side head gasket blew when the new tstat got stuck... Ive already replaced the passenger side head gasket and everything was good, however the driver side on the #4 cylinder has a hairline crack between the valves. Its clearly been there for awhile but i still went to the local jy to see if i can pull a good one to no avail same issue there as well. Well i parked the explorer till i could decide what to do with it and used my car for work. Well said car blew up on me in Sacramento and now i need the explorer to get back to work.
So what i want to know is if i can use this head till i rebuild the motor for a Ranger I'll be towing home soon

 

[moosemeadows]

had a similar issue with a Ranger at work. Went to Oreilly's and they had some stuff to seal it up. Was a little spendy but cheaper than getting a new head. Give it a try it worked for me and that was 6 months ago.

 

[RonD]

4.0l OHV heads had weak spot in the casting and would crack between valve seats when overheated, head metal expands too much and cracks.
That's also why overheating blows head gaskets, head gets very hot and its metal expands, and since it is held in place by the head bolts it can only expand down, so crushes head gasket between head and block.

That crack is a coolant leak into the #4 cylinder, no maybe about it, so same as blown head gasket, it has been there since it was overheated so would have same symptom/signs of blown head gasket, you can take the head to machine shop for pressure test but it IS a coolant leak into the cylinder, so waste of money to test it IMO

You can run the metalic/glass Head Gasket Sealer in cooling system, the heat inside the cylinder causes the metalic/glass particles to melt and seal the coolant leak temporarily, it is constantly being removed and resealing so you must leave/run the sealer in the cooling system, all the time

And it does work, and no it doesn't clog cooling system, old wives tail from mechanics who want to repair head gaskets, lol.

BUT......................it doesn't fix the problem, and crack can/will get bigger and this type of sealer will no longer work, so at some unknown point in time engine will start overheating again(pushes out coolant) and sealer won't fix it.

So really up to you and the time and money it takes to swap heads.
New gaskets and head bolts.

I would just get new/rebuilt head so I only had to do it once

 

[Jerlaine]

I already started putting it back together. As i said before the motor will get pulled fo ba rebuild, and as much as id rather to do it right the 1st time i don't have the funds at the moment to do it.
So hopefully that temp fix will last long enough

 

[RonD]

I ran 4.0l with cracked head for over 9 months using Head gasket sealer, it does work
Follow instructions
The heat up and cool down time is important when you first use it

And carry a spark plug wrench that can pull out #4 spark plug.
While it is a long shot the seal can fail after you shut engine off and head metal cools down.
Coolant will leak into the cylinder and when you go to restart you get a hydro lock.
Unhook coil packs 4 wire connector, for No Start, remove spark plug and crank engine to clear out the coolant
reinstall spark plug and hook coil pack back up
Start engine, it will smoke a bit but it will reseal itself