i have an 87 240 wagon. excellent condition. the water pump is new, as is the coolant, t stat (71 celcius) hoses, belts, and water temp sensor. I also know the gauge is correct because i fixed the compensation board. Ok so now in this brutal mississippi heat, with the air on, the gauge climbs and climbs until its in the red. If i was to be stuck in traffic, i'd be in trouble. On the hwy, its not so bad. Oh, also replaced the overflow jug and have the lower pressure black cap on it. ??? ideas?

 

Plugged radiator? Feel around the radiator to see if it's uniformly hot...

 

I would install the tropical fan clutch and/or the auxiliary front mounted electric fan that is found on the 92-93 240's ... make sure the radiator is clean, use a pressure washer from inside the engine bay pointed outward.

 

my radiator is uniformly hot to the touch on all sides, and both hoses are hot, as they should be. I dont have an infrared temp taker thing, so that's out as far as checking temps accurately, just used my hands. When i got done driving tonight, i turned the car off and spun the fan, It had some resistance, but I'm not sure how much it should have ??? It spun freely, maybe not as free when the engine is cold though. What is a tropical fan clutch? and yes, i was considering a front mounted auxiliary electric fan. Guess i could just wire it to a toggle switch? i'll also do a radiator flush ...couldn't hurt.