Eliminating the heater core? Hose routing?

I've upgraded my 88 MJ to a open cooling system.
I've also bypasses the heater core all together, and I have a short hose
from the water pumped looped over the top into the the thermostat cover.

Is the correct? Will this bypassing the heater core affect the cooling?

Would it be better for the effieiency of my cooling system to keep the flow through the heater core as it should be, and use the suggested "New Style Heater Valve" that is necessary for the open system upgrade?

I ran my 89 like that till I could do the heater core. No ill effects at all.

the heater core acts like a second radiator......it will keep your motor cooler,probably not by much with out the blower running.

If you don't want a heater, it's fine. It gives you a bit less surface area to cool. You could however, just eliminate the valve and run the hoses straight through the core, unless your core is shot.

Keep searching

barillms said:

I've upgraded my 88 MJ to a open cooling system.
I've also bypasses the heater core all together, and I have a short hose
from the water pumped looped over the top into the the thermostat cover.

Is the correct? Will this bypassing the heater core affect the cooling?

Would it be better for the effieiency of my cooling system to keep the flow through the heater core as it should be, and use the suggested "New Style Heater Valve" that is necessary for the open system upgrade?

Click to expand...

What you did is OK, the flow between thermostat housing and the pump is important. Part of what the heater valve does, is bypass the heater core and thermostat some.
The bypass is important because it keeps a little flow going around the thermostat, giving the thermostat sensor a coolant flow with a more actual engine temperature, during warm up, air flow and coolant flow changes. This helps avoid wild temperature swings in the system, until the coolant temperature homogenizes some.

My Jeep is overheating, and I'm trying to figure out why. I don't have a heater valve, I don't need heat, so I've bypassed the heater core.

It only overheats when I'm going slow in Low Range.

If the above mentioned hose routing won't cause any Ill effects, then I have my overheating problem narrowed down to a sensor or distributor needs adjusted which is making my timing advanced.

With the new OPEN style radiator, is there any other things I must change or modify to have my cooling system working properly?

I have an 88 Comanche with a 4.0.
The damn thing runs hot, and the engine seems tight.... like its hard to turn over and start.

are your cooling fans working properly and putting out enough cfm's?