2001 LR Disco II. 225,000 miles. I installed my coolant temp gauge this past weekend and while I am not over heating I am running hotter than I should be. I have the OEM temp thermostat which I will be replacing with the cooler 180* warm climate thermostat. The thing that has me puzzled is my temp readings at speed. Puttering around town it's in the 210*F to 215*F range but going down I-75 at 70mph my temps climb to 225*F to 230*F . The water pump is less than a year old. I have recently flushed the cooling system and have a 50/50 of coolant. The axillary cooling fan is running it's little heart out trying to do what it can but I am suspect of the cooling fan clutch. I found LR part numbers on the fan clutch so I'm leaning towards it being original. I'm thinking the cooling fan is "slipping" under heavier load/speeds. With the factory temp thermostat I should be seeing temps closer to the 200 to 210 range (Hot humid Georgia summers). With the cooler 180*F thermostat I should stay under the 200*F mark.
Am I looking in the right direction or barking up the wrong tree here?


Thank you in advance.

 

The fan is not supposed to do much at 70mph. I would insert stiffener springs in the water pump suction hose and radiator outlet and evaluate results. Simple and cheap enough for diagnosis.
I suspect a hose is collapsing because the radiator impedes full flow from built deposits, or weak hoses, or some defect in the thermostat, or several of the above.

If has the same behavior with stiffeners, and a good thermostat, the radiator has timed out. Come back with observations.

 

yep ^ if you are going 70 and temps are climbing it is not a fan or fan clutch. fan wont generate the amount of air flow that 70 produces. check the cavity between rad and ac coil for sheetmud or stuff, but my $ is on radiator sludge.

 

I have some recent posts on the same issue. My bet is on the clogged radiator.

How old is your radiator?

 

Radiator fin occlusion or the radiator itself is plugged.

At 70MPH, you're flowing way more air through your radiator than your fan ever will.

 

Best i can tell the radiator is original. I already used the pressure washer to clean out the area between the radiator and condensor and coolers.

I will use my ir temp gun to see what the radiator is doing across the core.

Very interested to see what happens with the 180 thermostat too.

 

what kind of t-stat did you put in? was it a gray LR t-stat or was it white?

 

Original at 225K.... you are due for a new radiator. Cheap insurance, especially when cooling issues will greatly affect the reliability of your engine.

 

For cooling - don't screw around.

Replace =- Fan clutch with Hayden HD one from eBay new.
Replace radiator with a Nissens from rockauto.com
Replace thermostat with a grey genuine land rover 180 degree.

And that's it.
The trifecta.

And you'll be set for a long time.

Failure to do all the above - then you'll have cooling system problems.
It is worth $225 for the new radiator and $70 for the fan clutch and $70 for the
thermostat to kill this cooling problem once and for all.
That's what i did.

 

Jfall- Do you have the fan clutch part number?

Thanks