I know mine works cuz in this -20 below crap when she opens up I lose about 40-50 degrees within seconds. The heater goes from blower super hot air to freezin cold. BRRRRR

The question is.....
Is this fast decrease in temperature a bad thing. Potentially harmful??? I have notice I am getting some leakage of antifreeze from the top hose into the engine. I assume it is being caused be this.

its potentionally harmfull ...But not any more so than yer avitar pic, and I am gonna assume you have a 4litre??? I wouldnt worry about that too much ...4 litre Blocks are the toughest fawkers out there ....I have never heard of a 4 litre block cracking ... I put one to the test this summer In Drum .... Boiled it about a dozen times one day triing to get from one place to another...(about 12 k) used river water to cool on outside of block ...tough fawker it is

Besides everyone of us is in that same boat right now unless we dont all have T-stats in our motors


anyway if yer that concerned ...stop by yer local UFA and pick up a Tractor Block heater(I really dont know whats it called But I know it was desinged fer tractors and wagons with out block heaters) what it is .... Its a little tube about 10-12 inches long that you put in line with yer upper rad hose .... it has a heating coil inside (so you need to plug it in) and has a little electric pump as well ...it heats up yer coolant and circilates it thru yer Block ..... Its ment to work on a wagons without a stat but it will open a 170 degree stat. Works fawking great

as fer yer leak .... Yea its a possibillity But I am willing to bet its an old hose and could stand a replacement or a loose hose clamp

Not terribly concerned unless I should be. Hose is good....clamp maybe a bit lose as it is one of thoughs stupid automatic squeeze clamps(not sure what they are called but I know they don't work to well) might go ahead and change it. Leaking never occured entil this last cold snap.

I think I'll just grab a chunk of cardboard and place it in front of the rad. It might help a bit.

yep you could do that too .....

be sure to cut a hole in the mille of that cardboard ....where yer fan axel would be .... 3" ...its easier on the bearings that way

Hey Mike,

That is common with yj's. I found by flushing my heater core with tap pressure and water, then flushing the system, then replacing coolant 50/50 (glycol/distilled water), the heater temps will be more constant and a lot hotter, and you won't get such an erratic fluctuation. I do this every fall. Make sure ya use distilled water, because the minerals in tap water can scale up your rad, heater core, water pump, and everything else in the system, and cause the same problems again very shortly. Old contaminated coolant can really gel up the rad and heater core, especially with mineral scale. You'll have major arctic highs blown' out the heat vent's while your engine is overheating.

As long as the coolant's circulating properly and there's no air in the system, the head & block will be fine. I would check the coolant level and do a flush (really wash out the heater core), this should clear up a lot of the heating and fluctuation problems you've been havn'

If your heater is suddenly going cold then you have an air pocket in the cooling system, when it hits the heater core it displaces the hot coolant thus giving cold air. Fix the leak and top up the rad and coolant overflow tank. Run the engine at 1500-2000rpm until it reaghes operating temp with the rad on loose(the first stop). This should purge the air. Hopefully your t-stat is installed correctly with the air bleed hole in the 12 o'clock position or bleeding the air out may take a lot longer.