Over heating question

so I replaced my water pump in my 89 6 cyl and replaced the thermostat upon reinstallstion and now when I start it n leave it idling the overflow bottle starts boiling the water n I get up around 220 degrees so why is my thermostat not opening and having that water dump into the radiator like it should? Its a closed system so is there some secret to getting the system filled with water?

Did you bleed the air out of the system after your repairs?

I think so. Could u run the procedure by me?

On mine (open system) it's easy, just squeeze the upper raidator hose, see air bubbles come out and fluid level drop, add fluid and repeat, then run the engine a little while and repeat.

But I think I remember reading that it's different for the closed systems - that's why I raised the question. Something about it even helps to park on a hill a certain way so the air rises in a certain place. Try searching with the word "burp" or "burping" and "closed system" - or maybe somebody with a closed system will comment soon.

Do you know if the 1998 is an open, or closed system?

here is a pic of my setup i have a draincock on my thermostat i got a housing off a 92' and it had a sensor so i put a draincock instead to bleed out the air but when i start the jeep with the bottle full of water i dont get any water coming out of the draincock even after reaching 210 degree's. im running open thermostat now just to check but how in the hell can i get some water circulating so i can fill my jeep back up?!?!!

Most of the Renix, closed system guys here have long drawn out almost religious ritual for burping the thing. I just leave the upper hose loose at the thermostat housing and fill the coolant bottle, cap off so it can bereath and let it fill the block and radiator through the water pump by pass to the heater core, but I do not have one of those CS heater valves in the way of the flow in the heater hose, so if you have one of those it must be open too I think, but I am not sure. Anyway the trick is to fill it through the bottle, and have that upper hose loose until it flows out both openings, i.e. the cap and the hose. You won't see much if any flow at the thermostat.

alright so i should loosen the top radiator hose from the thermostat and fill the overflow bottle, cap it off, and let my jeep overheat until what?

Mopar It said:

alright so i should loosen the top radiator hose from the thermostat and fill the overflow bottle, cap it off, and let my jeep overheat until what?

Click to expand...

Not exactly, Jeeps don't overheat with the engine turned off.

With the engine off, disconnect the upper the radiator hose, elevate the open end of the hose some, then pull the bottle cap off, and add coolant to the bottle as the coolant drains into the block and the radiator. It will push most of the air out of the block, into the radiator and through the radiator and then out the top of the radiator into the upper radiator hose.

Then when the bottle stays full and no more air comes out quickly reconnect and clamp the hose to the thermo housing, reinstall the bottle cap, and fire the beast up *turn on the ignition, don't set it on fire, LOL).

That is all I have done the last three times I drained the radiator or engine to work on mine. Only had to add about 1/4 of a bottle of coolant to the bottle after a days drive and it never overheated.

are you running 100% water? you still need coolant or your water will boil no matter what

On my 87, 89 & 90 all are closed system, fill the bottle on the firewall then start the engine with the cap off. I do this on level ground. With the heater on hot bring the engine up to 1000 - 1200 rpm & it will bleed the air out of the little hose that comes in the side top of tank. keep the tank 1/2 full during this untill no more air comes out of the little hose. I've done this twice on the 87 & once each on the other 2. Never had a problem getting the air out.

I just pick the jeep up, throw it over my shoulder an tap on the roof till it burps.. SORRY i did mine the way ecomike said, works great...Again sorry for the joke.... HTH