93 4L 4x4 Weird Cooling Issues

[85spraybomb]

hey guys, I've already tried to search up as much as i could on this but I can't find the info I'm looking for so any help is appreciated.

First off, the truck is a 93 Ranger X Cab 4.0 5spd 4WD.The truck has 92k on the odo but the title says its exempt so I'm not sure of the correct mileage.
The truck has been having some cooling issues lately. Ever since I got the truck it seems like it either leaks/burns coolant, I'm leaning more towards burning because i don't see it on the ground and there is nothing wet on the engine. I usually add a jug of coolant every 3 weeks or so. My daily commute is about 16 miles round trip and the truck usually runs fine. On two separate occasions when my dad has driven it to work which is a 60 mile round trip, on the last stretch coming home which is about 3 miles from my house and is a HUGE hill, the trucks temp will come up around 3/4, on these two occasions when i would get home and open the hood, the truck would be forcing coolant out the reservoir where the overflow hose connects to the reservoir. this was on two separate occasions like i said,but they were at least a month apart. The weird part is that i drove it on a 125 mile round trip drive the other day and it behaved fine with no overheating issues whatsoever. So I'm stumped, I'm going to try changing the thermostat and putting freshly mixed coolant in and see if anything changes.Also, the gauge seems to be off because it never stays solid for long, it usually runs between 1/4 and 1/2 most of the time and fluctuates between them.
So if anyone has any ideas i would greatly appreciate it. I love this truck and don't want to have to get rid of it.

 

[dankhimself]

Forcing coolant into The res is caused by combustion pressure leaking through the head gasket into the cooling jackets and causing it to overflow. The gasket leaks could be just from a damaged gasket, or a combination of that and warpage of the gasket mating surfaces. The fluctuating temp is probably caused by air in the coolant system, with coolant sporadically touching the temperature sensor, causing the fluctuations.

Kinda stinks to have that problem. I'm not an auto mechanic, I'm a motorcycle tech so someone else could probably give you a better idea of what your options are, from a financial point of view. From a technical aspect, that is the only cause of constant coolant loss when it is forced out of the reservoir like that. The combustion in the engine is the only pressure created around the coolant system high enough to force it out like that, so those gaskets are what need to be assessed.

 

[Andy D]

start with the cheap easy stuff. It may be as simple as a bad pressure cap or fan clutch. Borrow a pressure tester or just replace the cap. If you can smell anti-freeze in the exhaust or have a steam cleaned plug, then start thinking about gaskets,

 

[85spraybomb]

I'm going to order an oem motorcraft thermostat and buy some coolant and distilled water and do a 50/50 mix. Do I need gasket sealant for the thermostat housing? And what is the most effective way of burping the coolant system?