Is you XJ overheating??? Clean your radiator.....

I've been trying to figure out my cooling problem for some time. After numerous thermostats, water pumps, wiring the electric fan up full time, radiator flush after flush, expansion bottle, even playing around with a filler neck and radiator cap on a closed system, I think I finally found the problem, my radiator was FILLED WITH GRIME. I shined a flashlight through the fins and there was only one small spot where I could see light shining through. It was just filled with grass, oil, dirt, mud, etc. Its no wonder it was overheating. Heck my tranny will probably even run better as the side it circulates on was especially bad. If you've got an overheating problem that you can't figure out, try pressure washing the radiator.

Yep, a gumby put dex cool in my radiator and within 6 months it was plugged, but it looked good. I changed nearly everything before figuring out the real problem. The long horizontal passages are small and prone to clogging even without the "deathcool" GM crap.

Pressure washing the radiator can bend the cooling fins over depending on the amount of pressure its putting out. My friend bent all the fins over on his brand new 4 wheeler blasting his radiator out. So you should be carefull...

jeepthing07 said:

Pressure washing the radiator can bend the cooling fins over depending on the amount of pressure its putting out. My friend bent all the fins over on his brand new 4 wheeler blasting his radiator out. So you should be carefull...

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X2

Rust belt owners should exercise extreme caution pressure washing an older radiator, because the corroded fins can blow right out, and without fins, it will overheat for sure. Compressed air can do a pretty good job if you're careful, but if the fin rot is bad enough, you're out of luck anyway.

good point about rust, course I live in central florida so thats not much of a concern.

ocalajeeper said:

good point about rust, course I live in central florida so thats not much of a concern.

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Salt air causes just as much rust.:exclamati

mcnamaag said:

Salt air causes just as much rust.:exclamati

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no salty air this far inland I'm right in the middle of the gulf and atlantic, just hot as hell with no breeze.

Every time the XJ is washed, thoroughly rinse out the radiator and condenser fin area. Especially true after wheeling.