Brother's Range rover P38 2.5 diesel (1999) i suffering from occasional overheating. We have been slowly working through all the usual issues. New water pump fitted last year along with a new thermostat. There are no leaks in the system except through the overflow on the the reservoir when it overheats. Engine compression is excellent reading on the high end of the tolerance range across all cylinders. The heater system inside blows hot so no air leaks there. We believe it to be the baffle in the radiator as the top of the radiator is .very hot but the middle is only warm at best. Before spending oodles on a new radiator there are two questions which baffle us - not difficult at our age but we have got nearly a hundred years mechanic experience between us!!!!! The are two issues

1. When the engine overheats the coolant level rises in the expansion tank and vents through the overflow. When it cools it falls back to normal level.
2. He has driven the old girl for weeks at a time with no problems, then it the needle shoots up the temp gauge as it overheats.

The first could just be the expansion of the coolant as it gets hot. The second could just be more stop/starts on the last journey. Are there any other suggestions????
Cheers, Mike

i would go with the baffle as it's a known problem, try and find a hand held temp thermometer and check the temps around the radiator.

I had this issue fairly recently, same symptoms regarding the rad. I have an alloy rad and after checking the baffle was in place I suspected I had a blockage in my rad. I spent a fair amount of time flushing the thing through with a high flow pump from screwfix. It would still over heat.

What I found was that at low RPM, when loaded, such as after cresting a steep hill, it would get very hot. Keep the revs up and it would cool down.
My water pump was only a year old (metal impellor type) but in the end I replaced it anyway just to discount it if for no other reason and it fixed it! I could see nothing visibly wrong with the old pump, the impellor and pulley were both still tight on the shaft. Either way, a few thousand miles later, including some spirited driving to load it up and make sure, and it has been fine.