Just because you got a new thermostat doesn't mean it's good...
What are the symptoms...Tell us exactly what is happening...
Overheating is a little too generic... Idles fine ? Then heats up when you drive it ? Then you gotta look at the radiator or air flow thru the radiator...Or your new thermostat is not opening fully... Bleed hole at the top ? Trapped air ? Have you burped it ? Lot's of things could be going on....

John

 

John, the truck idles fine and then begins to overheat when I drive it. Bleed hole is at top but it does need to be burped as I can hear a lot of air in it coming from under the dash. My guess is their are air pockets in it but i can't seem to get them out. If anyone has a fail-proof method, I would appreciate any help as I'm running out of options

 

This has been explained before in other threads.
195F = 90.5C
Per the manual, factory thermostat is 88c = 190F

The factory thermostat is supposed to be fully open no higher that 89C, or 192F
Through testing I've found that 195F thermostats aren't fully open until 200F or higher.

The same tests have shown a 180 to be fully open at about 190 which falls in the range stated in the manual.
Thermostats in the US appear to be labeled with the temp that they start to open, as opposed to the UK where they are labeled with the fully open temp.

So, if it's a Land Rover thermostat, 88 is correct. If it's a Stant, Gates, etc., 180 is correct.

Given that the overheating began immediately after a coolant service the most suspect thing is that the shop installed a 195 from the auto parts store. However the OP says he provided a Land Rover thermostat so that should eliminate the thermostat as the cause, unless it's stuck closed. I've had new ones fail, but usually in the open position.

 

I don't get it why doesent every one who has a odb2 port have a ultra gage ,it is the rover crystal ball , every time a rover overheats its like playin Russian roulette . One day you will lose . The factory gage blows , good or meltdown . With a ultra gage you no way before its surface of the sun hot ! Just sayin blamo.

 

With the engine warmed up turn it off and try to turn the fan by hand. It should be somewhat difficult to turn. If it turns more or less freely it's bad and needs to be replaced. You can get a new Imperial that will fit at your local parts store for $50 or less. I can't remember the part number off the top of my head, but search the site for "imperial" or "hayden".
To get the air out, which is generally easier on the D1 than DII, just remove the plug (you do have a brass one right?) from the top of the radiator tank and, with the engine running and reservoir cap off, add coolant to the top. I'd make sure you have someone watching the temp so it doesn't overheat. You can raise the front right side a bit which might help some.

 

Gurgling noises coming from the heater could also be a blown head gasket..

This will certainly cause an overheat as well..

Since you're going to have to burp it anyway, I'd get that thermostat out and check it...Put it in a pan of water on the stove with a candy thermometer..
Make sure it's working as it should...

Do a pressure test on the cooling system as well..

Good Luck

John

 

You checked your coolant level, right?
Is your serpentine belt routed correctly? People have been known to get this wrong, causing all sorts of problems. Any white clouds coming from the exhaust that smell suspiciously like antifreeze? Milky goo in your oil?
First off, talk a little bit more about what the truck is doing. Are we talking off the scale having a meltdown overheating? Or above 212 on the Ultra-Gauge? Does it happen after ten minutes at idle? In traffic? On the highway?
It doesn't say much for your "mechanic" if all this started after he did a coolant flush.

 

Thanks everyone for the help

Here is an update from where I'm at. I tested the fan clutch and yes, it's bad so I'm picking a new one up tomorrow. I hope this fixes everything. In response to the serpentine belt, it is on correct and has been checked. Also it looks like I need to invest in an ultra gauge but have avoided it up until now because I never had issues with the truck overheating. And yes, I do have the brass plug as the plastic one are crap. I'll update more tomorrow as I replace the fan clutch and try to burp her once more. Thanks for all the help

 

Since you do a lot of in-town driving it should make quite a difference. NYC taxi cab service in the summer is about as bad as it gets on a vehicle.

 

So here is an update on my Rover at the moment. The truck needed a new fan clutch and water pump and so I replaced both of them along with all new hoses and it's running great except the damn gauge keeps telling me that it's overheating. For the first 100 miles, the gauge was working fine but since then, it keeps telling me it's running almost in the red.

I bought an Innova 3130 after DiscoMike suggested it to me and the gauge is telling me that the truck is running 178-190 on the highway (depending on outside temp) and 185 - 201 in traffic around NYC streets. Does this sound correct? If it is, how can I fix the damn stock gauge as it's driving me crazy and I never had a problem with it in the past

I know these gauges can be misleading but something is telling it that my truck is running "warm" and I want to fix whatever that problem is

Thanks a lot