Fitted a brandnew short engine (Not rebuilt)about 6000miles ago to my Range Rover P38,4.6HSE. Up until recently everything was fine until the weather started to warm up. I was stuck in a traffic jam recently and the temperature gauge went up and the warning light came on for the first time ever-I did not lose any water as a result. A few days later, I was driving at around 60mph and the temperature started to suddenly rise again but did not hit maximum. I decided to fit a new thermostat and all was fine until a couple of days ago when the temp. started to rise again whilst on the move. The car is not losing one drop of water, the water pump was replaced when the new engine was put in and a new drive belt fitted. The coolant is clean without traces of muck etc. and is a 50% mix of anti freeze and de-ionised water.
Question-should the twin Aircon condenser fans cut in to assist the engine fan if the engine temp. rises too high??-mine did not.
The old engine never gave this problem even when towing on the hottest of days-the needle just sat smack in the middle and never moved.
Any of you guys have any ideas??
Can I test the efficiency of the viscous fan coupling in any way??

 

how old is the radiator cap?
how old is the radiator?

i had a similar problem (ie. the truck would show it was running hot, but it would not use a drop of coolant)it turned out i needed the radiator professionally cleaned or a new one fitted ... i opted for a new one.

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you may also have air stuck in your cooling system ... find a steep hill and park the front of the rover pointing upwards -> remove the radiator cap -> turn the heating system on high -> wait for the engine to burp.

the coolant rushing to the heater core should force the air out in a few minutes...

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yes the cooling fans should kick in, once the temp reaches too high ... i would definitely assume the truck is running hot as your are.


good luck,
-jeff

 

overheating is the most common cause of serious engine failure...you should regularly check the working conditions of the radiator.constant exposure to heat and engine fluids will eventually damage the part.repairs are just for temporary concerns..most probably installation of the new radiator was the best way to do..i had just made landrover radiator installation a couple of weeks ago..as the mechanic checks for the part, he told me to have replacements..

 

Your electric fans should be coming on either when the engine goes above the normal operating temp and when the a/c is on. If not I would not drive the truck till you get the fans working. Most Rover engine, even new ones won't last long if you allow the temp guage to go into the red and trigger the warning light, you will drop a sleeve and be looking at another engine replacement.
Mike

 

dont know the mileage of the vehicle's radiator, or clutch fan...theseare suspect to me since youve replaced most everything else, air in the system is a possibility as stated above, you would hear gushing sounds behind the dash upon acceleration usually when this is the case...If your not loosing any coolant, then I would focus once again on the radiator since you replaced the water pump...Im not certain if the drive belt is automatically tensioned, got another brand on my mind right now...but check and see if it can be tightened, if it can and is loose it could be slipping not allowing for increases in rpm etc. check the clutch fan to make certain it gets progressivly harder to turn in proportion to the rise in temp of the engine, check the resistance when cold, then hot by manually turning it as the engine is off, you should feel a noticible difference. My electric fans, had a rather large insect blockingone of the fans upon inspection, once removed and cleaned, I manually rotated the fans, turned on the ac, as the temp rose the fans ran as designed.