|
WyoJeeper 01-25-2009, 03:45 PM I have a 1989 GMC 3500 with a tbi 454. At speed it likes to run at 215 degrees and as soon as I slow down the temp drops to 210 or less. I have replaced the water pump, thermostat and coolant. I am thinking it might be the clutch fan or the radiator itself. Just looking for some ideas. This is my daily driver and soon to a solid axle swap candidate. GMCTruxrule 01-25-2009, 07:09 PM If it was the clutch fan, it would cause overheating problems at low speeds, and stop and go traffic. More than likely a clogged radiator. HAPPYJOHN 01-26-2009, 06:52 AM More than likely a clogged radiator. X2, Test by starting cold engine, touch top hose till it gets quite warm. then check lower hose. If it's cold- low radiator flow= Replace/repair. GMGuy 01-26-2009, 05:57 PM Quick but not infallable fan clutch check: Get the engine and cooling system good and warmed up [by driving it around, not just getting it up to operating temp, need everything hot]. Get a helper, open hood, watch the fan as your helper shuts off the truck. If the fan keeps spinning your fan clutch is shot. A bad fan clutch CAN cause overheating at highway speeds. BTDT. Alex. | |