2003 LR3 SE overheating...

Bought a 2005 LR3 last month with about 120K on the odometer. Not my primary driver so I haven't driven it a ton since I got it, but there are some issues cropping up already. I've been getting a "Low Engine Coolant" warning, even though I've topped it off with the recommended orange juice. No puddles or detectable leakage of coolant.
Car ran fine 2 days ago for a 100 mile trip, and ran well for some errands around town yesterday. However...I started it this morning (about 40*F outside) and let it run for about 5 minutes before driving. No heat at all. I had about a 2 minute ride with no issues other than no heat, then as I was driving up a steep hill I got the "Reduced Engine Performance" warning and it seemed to really struggle even on level terrain...when I parked a minute later, the car overheated in a rather spectacular fashion. I let it cool for about an hour and drove it home with no issues (heat came on at first, then died out again) until I got to a hill in my neighborhood and it overheated again. I popped the hood and could see the steam was mostly coming from underneath the plastic engine cover, seemingly from the drivers side. I have seen a thread on here where this problem had been encountered before but I don't see a resolution. Thermostat stuck, I'm guessing?

The low coolant error could be related to a bad float in the reservoir. The obvious first choice would be the thermostat. Replace the whole assembly, crossover comes with the thermostat. Following the service manual, you will want to properly bleed the system, these are very finicky on this part.

The other things to consider is the viscous fans, which do go bad periodically, see if you can figure out if it is running, and a blocked radiator. Other issues might be worse to diagnose.

You should be able to carefully inspect the engine to see if there is telltale white stuff, where coolant has leaked and burned off.

If steam is coming off under the engine cover-- check the little plastic elbow for cracks, leaks. The engine cover will come up easily with four screws. There is a hose coming from the plastic cover to an elbow, and going under the plastic intake. Other options might be head gaskets...

Thanks for your reply...I pulled off the engine cover and didn't find much white crud except a little around/under the clamp for the smaller hose off of the thermostat elbow. Most likely from this morning.
I have a new OEM thermostat and gasket on order for next week...none of the places around me carry these in stock unfortunately. So when I pop a new one in we'll see what happens.
Yeah I thought maybe head gasket because of the load the engine was under when things started to go south. But would that affect the heating system, which wasn't working at all even before the vehicle was in gear? I added some more coolant and idled it with no problems but it's still blowing cold air with the heat on high.
Is there a service manual available online?

Drop me a pm with your e-mail address.

I have experienced two of the things here.

First with the low engine coolant - I was getting the same error message despite the tank being full. I brought it in and the bad float TLT mentions was the culprit. Replaced the entire reservoir, I think parts and labor were about $400. (LR Dealer)

The next was the reduced engine performance. I bought about $10 worth of sprays and cleaned the Mass Airflow Sensor (MAF) with MAF cleaner. Next I cleaned the fuel deposits out of the Throttle Body with Throttle Body cleaner. Both of these things I did myself, the MAF took about 5 minutes, the Throttle Body maybe a half hour. If I were to do it again, I bet I could do it in half the time. I did a youtube search and there are some very helpful videos on how to do this. After doing these two things, I got about 1mpg increased mileage, experienced significantly reduced hesitation when doing a rolling stop/quick acceleration. Now I try to put a can of Sea Foam into the gas tank when I think of it. I read on here somewhere that other owners do these things with each oil change, which makes sense.

As far as the overheating, I can't help there.

-Bostonian

Thanks Bostonian...I'm seeing from some quick research that the float is prone to failure. Is the float integral to the bottom of the tank or can you swap them out (wondering why you replaced the entire tank)?
The "Reduced Engine Performance" warning and the overheating were events that had never occurred previously when I was driving the vehicle, but when they happened it was within seconds of one another climbing a hill. Although the overheating conditions were probably present prior to climbing the hill...it was a very steep hill...hence the lack of heat, and it was the engine load that pushed the coolant temp over the edge. My last two SUV's were a Lincoln Navigator and a Cadillac Escalade, and this Land Rover does not have the power off of the line those vehicles had. Honestly my grocery-getter Subaru is far peppier off idle. But on a flat-out run the Rover is pretty good. I just chalked it up to power/weight ratio...maybe the lack of power I've noticed since day one is not normal?

They're definitely not sports cars. At nearly 6k LBS it was a bit underpowered, which is why they eventually went to the 5.0 Liter. Nice.. but the 4.4 is tolerable.

Be sure and not confuse transmission overheat messages with engine overheat messages, as a side note.

I would not just replace the thermostat, I would do the whole crossover assembly which comes with the thermostat and housing, they're prone to cracking (more plastic crap)

My only complaint is low-rpm torque...I get respectable power when I need to pass someone, but it bogs for a few seconds during a quick acceleration off of idle.
I managed to get a thermostat shipped to me quickly and swapped it out this morning...I didn't do the whole crossover although I inspected it very closely for cracks. The heat works now and I drove it around town without the temp gauge rising above midway. But I'm still showing a "Low Coolant" message.
Thanks for the input for all that helped.

Quick update...went to drive the Land Rover this morning. Same deal. Let it warm up for a few minutes, and when I got in the car the heat wasn't blowing warm but it wasn't set on high either. Got maybe 1/8th of a mile before it overheated. Coolant level very, very low. So maybe I have a coolant leak somewhere? I drove this thing for 9 days with no problems including a couple of 100-mile trips. Have seen no puddles under the vehicle...but then again it's the fall rainy season up here in the northeast so it'd be hard to tell anyhow.

Water Pump, and a minor leak that is cooking off the coolant from the heat of the engine. If you are still fiddling with it, maybe you should take it somewhere at this stage. You are playing with fire.