RomanS

i have a 2000xj 4.0 and i started getting anti-freeze out of my heater/defrost vents inside the vehicle so i am to assume that the heater core took a dump, my question is has anyone ever by-pass one an a 4.0, if so i was wondering of any adverse effects, i just wanted to do it so i can run it the rest of the work week and get to it this weekend. if anyone had any info !! thanks

BudgetXJ

Just by pass it. You won't have any problems unless you trap air in the system when you do it. Burp it properly and you'll be fine.

BuckB91XJ

X 2. Do the bypass to get to work for the rest of the week, Bro. I've never seen the ole bypass trick "NOT" work on any rig. I had to do it when my heater control valve took a dump in the middle of the work week.

HelmuthJ

Reading this post caught my attention. I am going to change out the upper and lower hose along with the heater hoses in my 97 CherSprt 4.0....
What is the method to get the air out ??? Will it hurt anything to change the thermostat to a 180F from the 195F ???
Thanks HJ

BudgetXJ

You should stick with the 195 thermostat it is what Jeep designed it to have so stick with that. If you are having an overheating problem, going to a cooler thermostat is more a bandaid than a fix.

While filling the cooling system, remove the hose that goes from the heater core to the thermostat housing at the thermostat housing. Pour your coolant mixture into the radiator until coolant starts coming out of either the hose or the thermostat housing. Reconnect the hose. Fill the radiator the rest of the way. Start the jeep and let run until you get heat through the vents inside. The fact that you get heat through the vents means that you have no air trapped in the system as the heater core is where air will collect if its stuck in the system.

RomanS

thanks yall, and for that guy above, priming the heater core and elavating the front end seems to do the trick, gets all the air out

HelmuthJ

That is what I needed men!!!!! Thanks a lot... HJ