Save or salvage?

[Allen]

I have been slowly working on updating and improving my 1989 Comanche Pioneer 4.0 auto 2wd.  It's a farm truck, has been for a decade and doesn't get driven many miles a year, just hauling stuff from one area to another, running the trash to the dump, etc.  Today when I went to move it I heard a loud noise within a few seconds of cranking so I popped the hood and noticed the belt had broken.  Before I could get back to cut the engine off I heard another noise and as soon as the engine was shut off I heard the sound and observed all my coolant running out of the driver side of the engine block, below the exhaust manifold and above the oil pan gasket, in the area of the round shapes on the side of the block.  I can't get the truck to the mechanic until the middle of the week due to my work schedule, but I thought I would get your thoughts on whether this is a terminal failure or possibly repairable.  4.0 engines around here (central NC) are easy to come by for a few hundred bucks, but I don't know how to put one in, and honestly am looking at whether or not to part out/salvage the truck if the repair is too expensive.  Any idea what might have happened or how severe the damage could be?

[onlyinajeep726]

Where in NC are you located?

[Allen]

Lexington, NC

[Eagle]

Those "round things" are freeze plugs. They are cast into the block, have a round hole, and are plugged with a cup-shaped brass insert. The purpose is both to provide relief during the casting process, and to allow a place for coolant to expand without cracking the block if it freezes.

 

My guess is that 20+ years without regular coolant changes resulted in an acidic coolant that gradually ate away at a freeze plug (or three), and that the localized overheating resulting from no coolant circulation built up enough pressure to pop a freeze plug. If that's all it is, it's an easy fix: pop out the old one, clean up the hole a little, apply sealer to the perimeter lip of the new one, and gently tap it into place.

[Allen]

Nice explanation of the "little round things", I'll look into that.

[badazzelanore]

Good luck, hopefully its just a freeze plug. Got a pic of the leaking area? Also please try to keep her running. I have read some oretty amazing builds that start out as some old junky farm truck. A parted out/junked comanche will be gone forever.

[gogmorgo]

If it is just a freeze plug, and the rest of them are in good shape, not pushed out or anything, now wouldn't be the worst time to install a block heater into the plug that failed, if you don't have one already. Useful useful things (if you remember to use them, but I keep forgetting to plug in the Lada's). Also while you've got the coolant drained, it wouldn't be a bad time to do a bit of a flush and swap out the thermostat for one from a dealer, if you can.

[Allen]

Checked more thoroughly today, it is a freeze plug, almost completely out! I'll probably get the jeep to mechanic for the plug and a few other things this week, the get back to the list. Thanks!

[dasbulliwagen]

I'm just down the road from you in Asheboro. This site had been a huge resource for me and my 87 as I'm sure it will be for you. Let us know how this fix works out. These trucks deserve to be kept on the road.

[Eagle]

Checked more thoroughly today, it is a freeze plug, almost completely out! I'll probably get the jeep to mechanic for the plug and a few other things this week, the get back to the list. Thanks!

 

You might consider a preemptive strike, and have him replace all the freeze plugs he can easily get access to while he's at it. There are several that are a major PITA to access, and maybe those are best left until it becomes necessary, but I think there are three or four on the driver's side of the engine block, and it might be worth considering replacing those.

[dybamx]

if one went bad, the others are probably not too far behind it. change as many as you or your mechanic can get to