Just completed replacing the water pump and radiator on my 4.4L LR3

topped off coolant reservoir started truck, idled it for a few minutes, then revved at about 2500 RPMS for about 2 minutes with heater on full blast. Was watching my coolant temp via GAP tool. Turned off the truck then topped off the reservoir again,

Repeated procedure with the reservoir bleeder open to let air escape, GAP tool was showing about 228 degrees F, coolant gauge was dead center, but still blowing like I had the AC on. I never heard the thermostat open.

I didn't even get one gallon of coolant into it and I think I should get about 3 gallons into it.

Possible Bad Thermostat, even though it was good when I took the radiator out? Any other thoughts? First time replacing the Rad in a Lr3, could I have done something wrong?

 

Just tried it again, and went up over 230 degrees F, Gauge went up pegged high. Still blew like the AC was on. It has to be the thermostat, Right?

 

Sure sounds like a stuck t-stat but if so what an odd time. It has a small blender that lets air by very easily but fluid not so much. If you did not drain the system, 1 gallon may be all you need. The radiator itself does not hold much and the rear HVAC, if you have it, takes a good chunk of coolant capacity. Generally I just fill the system at the large upper radiator hoses first which fills the radiator and most of the stem, then add to the expansion tank. Idle and rev for a short bit adding to the expansion tank until it no longer drops - with the bleed port closed. Then I take it for a short drive, driving seems to be the best way to bleed these. But your temps seem rather hight.... Feel the large radiator hose on the right near the throttle body. There should be fluid in it and if you squeeze it (if not under pressure) you can hear the little check valve of the t-stat. And I have never in men entire life heard a t-stat open. They move slowly and vary in openness based on temp. They do not have just two positions, open and closed.

 

I replaced the water pump, So I would think pretty much drained. Right?

I do think I have rear AC, at least I have controls in the back seat ceiling/roof.

just put some more coolant, since went lower when I let it set. Cranked up and it got to about 222 F while idling. Still blowing super cold.

 

Have. you felt both heater core lines in the engine bay? If one is hot and one is not, then you indeed have a circulation issue. I would check the rear core for heat, make sure it is on and see if you get any heat back there.

 

DOAH! Didn't even think about that. Been spending a lot of time on her since I have a break and trying to get everything done. felt both, the upper coming from the rad felt a little warmer than the one coming from the lower rad into the thermostat.

I've now have gotten about 1.5 gallons in her. Going to keep going slow.

Never thought about topping off the rad from the upper hose, that would have been smart.

 

If you want to get fancy, take the wet shop vac to that breather location at the top of the engine and suck air out.

 

You talking about the top of the engine bleeder, the stupid plastic T bleeder? Been wanting to replace it with a brass t

 

Yup. That T pulls from behind the water pump and at the t-stat. You may have to clamp the hose after the T that goes to the water pump to force it to pull from the t-stat side.

 

I guess using my vacuum pump would do the same thing, like when doing power steering fluid. Didn't think of that. Great suggestion,