I've been battling an overheating issue for a few months now, possibly related to old issues that I thought I had solved. My 2004 with the inline thermostat mod overheats after about 10 minutes, or quicker than that if the truck is moving under load. I've done a coolant flush, even removing the two plugs from the block and flushing it out with clean water. Nothing noticeably gross came out. I also replaced the radiator. Last year, I replaced the fan because I had a similar problem. That resolved my temperatures at the time, so I don't actually know if this is related or not. Other than the coolant temperature itself, my only other symptom is no heat. I'm not sure how long the heat has been out because I lived in Florida up until right after this issue started, so I never ran the heat. So I feel like either my heater core is plugged, or my water pump is bad. I flushed the heater core both ways with water, and didn't see anything nasty come out, but that doesn't mean it isn't completely clogged. The hose at the top of the radiator gets hot, so some coolant is flowing somewhere, and coolant moves up and down in the expansion tank, but that hose never gets really hard if it's supposed to. I've tested the thermostat on the stove, and ran without a thermostat with no change in behavior. I've just done a combustion gas test in case I have bad head gaskets or a cracked block or something, but there was no sign of color change in the fluid. A compression test also showed no leaks. So I'm not sure what to look at next. If the heater core really is plugged, can it affect the flow of coolant enough to cause an overheat? How can I test the water pump to see if it's actually moving coolant as designed?

 

Water pump is cheap and easy enough to swap out I'd go ahead and do a flowkooler pump regardless. Old WP is moving fluid and they show they are going bad when they have fluid leaking out the weep hole in the back. With how quick it is overheating almost feels like air in the system. Does bleeding it solve the issue for any amount of time?

 

I've spent hours trying to bleed it, but I can keep trying. I actually did have some coolant leak from the plastic pipe that splits into three hoses, so I replaced that and the hoses that come off it. The rest of the hoses feel nice and soft. The expansion tank is only a couple of years old. I guess I can do a pressure test to see if there's an ingress point for air to get sucked in.

 

Have you tried pulling the t-stat and running with out one? Rule out a faulty t-stat. I don't know what kind of inline setup your running. I would also consider bypassing the heater core as well. Some good write ups on that. X2 on the FlowKooler pump. Are you loosing radiator fluid and having to add?

 

Yes, the thermostat is out right now, with no change in behavior. I also tested the thermostat on my stove, and it opened fully right at 190 degrees. I'm running Extinct's kit. I just took a look at the water pump, and I can't quite tell if there's a leak coming from the weep hole because I can't find it. There is a fresh drip right at the front of the block, though, so it could very well be leaking. I don't know where else water could be coming from to end up there.

I'm not losing fluid from anywhere except the expansion tank when it gets hot.

 

Check this thread: https://landroverforums.com/forum/di...23/#post937042

 

Thanks, Extinct. I'm leaning toward water pump in that case. When I replaced my fan last year, everyone told me that I would know if the water pump was bad. Anyone know if a FlowKooler water pump comes with a gasket?

**Edit** Bought the cheap pump from AB. Didn't seem like a FlowKooler was worth $50 more.

 

the flowkooler is worth every penny. The cheap pumps or any other OEM version are such a crap shoot. I'd gone through 3 of them with warranty replacement in less than 10k miles each and finally gave up and just did the flowkooler. All 3 of my rovers run them.

 

Hi.
I have an in-line shut-off valve in the heater hose. Kept closed all summers. Open in winters. Never 'overheated' but subject to whatever you call 'overheating'

 

What do you find is the advantage of that? Keep the core from getting dirty half the year? Keep the cabin cool?