hole in radiator

would a hole in the radiator cause the jeep to over heat and then go back down fairly quick? today i was driving and it hit just below 260 so i threw the heat on and went RIGHT down as soon as i turned it on... the 2nd and 3rd time it happened i wasnt so lucky it hit 260 and i imediatly killed the jeep left it with the key on and jeep not running, once it cooled down i drove it, did it again, killed the jeepp, finally i made it advanced and threw some anti freeze in it and it was boiling like crazy when i got back to work..... is it just the radiator that need replacing or is it something else

I hole would cause steam and constant overheat, unless it is a pinhole, then it may drop temp with the heater on.....

A sticking thermostat will do what you described.....

XBoBJ said:

would a hole in the radiator cause the jeep to over heat and then go back down fairly quick?...is it just the radiator that need replacing or is it something else?

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Yes, a pinhole will cause those symptoms. I just fixed that same problem. I had a pinhole @ one of the fittings exiting the rad. Smelled like anti-freeze, but there was none on the ground. Popped the hood as soon as I stopped the motor and saw it spraying mist/vapor onto the block.:repair: A little JB Weld and 50/50 mix made it all better! No more driving with the heat on when it's 95* out. Might be a good idea to let everything cool before reaching in there tho.

i know there is a hole, its definetly leaking... i got a 99 and have that skinny radiator in front of the radiator is that just the trans cooler, that thing is all dented up. should i just replace the t stat radiator and cooler

Before I did that I'd have the head checked, the 4.0 don't like getting over heated

razdrvr said:

Before I did that I'd have the head checked, the 4.0 don't like getting over heated

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dont say that........ how would i get the head checked? it runs fine no notice in oil pressure drop, once it hit red i shut it down no later than 5 seconds

You can run down to your local auto pars dealer and purchase a block checker or you could take the Jeep to your mechanic and have a block test performed. I'd suggest buying the block tester, they're handy to have around.