new rad same b.s.

hey all like to say thanks to all my naxja brothas who helped me out with my hard times i am doing great now guys. so long one short, 3 month coolant loss filling up overflow 2x a week, rad takes a mega dump,result, work done by a garage,new rad new t stat,600 bucks!!! got fed i know had no choice.1 month after,still refilling coolant 2x a week they damaged my t stat housing(does not leak there yet) and now my temp gauge goes from 40 to 100 andshoots back down to 40 then slowly back to 100 and repeat(sorry,i am canadian).oil gauge is solid,no milkshake in oil,and no prestone on ground.so where the hell is all this coolant going???also i personally changed the rad cap,i put on a prestone cap withthe locking lever,as the garage had left the original cap on there some info 1994 jeep cherokee classic xj 300 000km all stock inline 6 4.0l

Head gasket leaking coolant into cylinders?? Could pull spark plugs and take a look for differences. It's probably not leaking in to all of them. If you weren't always still adding antifreeze, it would seem like the coolant bubble issue where you could put the nose up in the air on ramps or a steep hill and burp the air out.

Could have a crack in the head dumping into exhaust, no milkshake & nothing on the ground. That would give white smoke out of the exhaust (steam). Try doing a pressure test on the cooling system, pump it up to the pressure on the cap, if it starts losing pressure look around as it has to be going somewhere. If it is going straight into exhaust when you start it up it will show at the tailpipe.

X2 Good thing to check if you have a pressure tester. Pump it up first, then start it. If needle pulses, that's another sign of head gasket leak (or crack) into a cylinder.

cool thanks guys

does your coolant smell like exhaust fumes?

Just read this thread, needing to diagnose my cooling issue as well. I have a '92XJ with a recently replaced radiator, and hoses. I smell coolant from inside the cab when driving with the A/C on. I cannot find a leak anywhere and I don't appear to be losing coolant. What could it be? Where should I start testing?

badandy said:

Just read this thread, needing to diagnose my cooling issue as well. I have a '92XJ with a recently replaced radiator, and hoses. I smell coolant from inside the cab when driving with the A/C on. I cannot find a leak anywhere and I don't appear to be losing coolant. What could it be? Where should I start testing?

Click to expand...

heater core

X2 on badandy heater core. Sounds like the start of a heater core leak. May not be far enough along to wet the carpet yet but may want to check for moisture there....

As for original OP, testing is the best way to isolate when you are losing coolant. Tests that come to mind include testing the coolant for presence of hydrocarbons, cooling system pressure test, compression testing and possibly the most valuable of all, the leakdown test.

Good Luck!