cooling problem, Help please I GIVE UP!!!

[bksmith]

My 4.2 in my '81 CJ-7 is running hot. According to my Temp gauge it is always running at the very end of the green band in the winter and last summer was on the H line. After driving it I can hear the coolant bubbling in the system and the radiator cap will have it's vent popped. I have replaced the water pump, fan clutch, hoses, temperature sending unit, temperature gauge in spedo cluster, 15# radiator cap, thermostat housing, thermostat (using 160 now, only way to "keep it in the green") and had radiator steam cleaned. It still seams to be running hot even in Kansas City's 20-30 F weather we are having now. I don't see any coolant in the oil and there doesn't seem to be any burn off.

I did have to run a wire direct from the sending unit to the gauge - my Painless harness has a break in the temp wire (not that it matters). I do not have a fan shroud. I have run out of things to replace and I am still running hot. My only thoughts are that my aftermarket products are causing to much heat in the combustion chamber or to much carbon build-up inside the engine.

Thoughts?

Brad

P.S. 258 w/ Holley 2bbl 500cfm carb, Clifford intake, headman headers, GM HEI distributor, stock heat range spark plugs, aprox 95,000 miles.

 

[White]

No fan shroud ? Start with that !
Next aftermarked rad. 3-4 core.
This is all assuming no one used a stop leak and clogged up the passages. ?

 

[bksmith]

i do plan on picking up a shroud in the spring. i do have a 3 row radiator (the heavy duty cooling option from the factory with the cap offset to the driver's side)

anyway, how could i flush out the cooling passages, is there a product out there that might do the trick?

thanks!

 

[Bounty__Hunter]

How far is the fan from the radiator?

Consider upgrading to an electric fan, then you'll free up engine power at the same time as getting a fan shroud. The OEM Ford Taurus fan is a good unit, and moves a lot of air on high speed (2-speed fan).

 

[bksmith]

the fan is about 1" away from the radiator. i would like to go electric but it is to cold here to go searching through the yards :shock:

what about the generic units sold at auto part stores? (like a 16")

 

[Junkpile]

You've got something wrong, it isn't your setup. The parts you have should be cooling if they are all working correctly. The fan shroud isn't as important with the long six as it is with the other engines because your fan is so close to the rad. It's still important to have one, but unless your cooling system is marginal for your application already, not having a fan shroud shouldn't cause any problems.

 

[Bounty__Hunter]

what about the generic units sold at auto part stores? (like a 16")

Mine lasted a little over a year before the bearings went out. Next electric fan will be OEM like the Taurus, built much better.

 

[bksmith]

well, with major overheating problems, I was going to wait till a 350 swap was available (money wise) but i might just do the 4.0 head swap. does anyone have a good source for a rebuilt 4.0 head? I have seen them on ebay but for like $400. Any other sources besides local junk yards?