Overheating issue in 87’ 2.5L comanche

[cadenjpeters]

Hello there, I have an 87’ mj 2.5L, having a serious problem with overheating. For the first two weeks i had it it was constantly overheating, then in one afternoon i put a new rad in, new thermostat, new filters, and an oil change. Immediately it solved the overheating issue. Been about a month now of smooth and perfect temp running, until it sat for a week then started overheating again. Before it was the radiator overheating, now it seems to be smoking out of the back of the engine block. I’m thinking it has something to do with the thermostat, if anyone has any ideas or solutions or want more information, please let me know!!! Thanks

[eaglescout526]

Well have you done a compression test to see if you have a blown head gasket? Have you flushed the system of any gunk build up and what not? Any other history on it? Perhaps a bad water pump?

[Jeep Driver]

There is a core plug at the back of the head. 

Also, your intake manifold is heated. There is a hose at the back of the intake which runs to the heater core. 

 

One of the two let go.