4.0L blues

[ktmranger]

Got a 93' that I still love. 179,000 mi, rebuilt xmission, major top end tune-up aprox 5,000 mi ago( intake gaskets, all, plugs, wires), thermostat, radiator, heater core, starter, ball joints, and other things i cant remember right now. Anyone know why I would be popin heater cores(2 in 7000 mi) and radiators(same mi) ? my motor is a 4.0L. Did the test kit to see if exaust gases were present in cooling circuit, which means a cracked head. 3 tests were negative. anyone gota clue?

 

[adsm08]

Coolant blockages can cause pressure build up in the system that can cause the solder points to pop.

It's also possible that you are having electrolysis problems (the cooling system acts like a battery) and eats away the solder.

If your coolant is nasty (or was before the first repair) stick a volt meter in your rad, see if you get a voltage reading. If you do, flush it out good, and if you want to put a few extra dollars in it, you can mix your coolant with distilled water and it can help reduce the electrolysis issues for a while.

Either way, the first thing to try is a good, long flush.

 

[kunar]

did you check the radiator cap? usually they leak, but i guess it could be holding too much pressure... or maybe it was replaced with one that holds too much pressure. not sure right off the top of my head what they are supposed to be, 13 lbs maybe?