During the hot summer days my engine overheats when it the rig slows on is not moving. I have to turn on the heater sometimes so the temp will go down.
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1995 Toyota 4Runner Question: over heats sometimes
Answer #1patrick mannion from Greg Solow's Engine Room, June 18, 2009, 11:37Master
Does your 4Runner cool fine at speed on the freeway? On the freeway air rushing through the radiator cools the coolant in the radiator and it is drawn back into the engine. In traffic you do not have air being forced through the radiator and as the coolant in the radiator heats up a viscous fan hub locks up and cools the engine. When the coolant cools down the fan hub un- couples and free wheels.
Check the coolant level in the radiator and expansion tank. Check that the fan hub locks up when the engine gets "hot" and finally carry out a block check to ensure the head gasket is sealing. I will send you of line an article I wrote that describes points I have mentioned.