Rick's Free Auto Repair Advice

Posts Tagged: overheating

Engine Overheats – GM vehicles

Engine Overheats No radiator fans on GM vehicles, Chevrolet, Impala, Pontiac, Buick, Cadillac GM uses a pretty nifty technique to control the radiator fans on late model vehicles. The system consists of two fans and three relays. When the powertrain control module (PCM) detects the need for cooling from the engine coolant temperature sensor (ECT) at 223 degrees or refrigerant pressure above 190-psi., it provides a ground signal to the low speed fan relay. Power flows to one fan, and the ground for that fan flows to the second fan. … Read More

Car overheats – Chrysler Vehicles

Car overheats – Chrysler products People always ask why their Chrysler car overheats. Aside from the mechanical reasons explained here, Chrysler products rely on a solid state radiator fan relay that can cause problems. The relay is usually mounted in the front of the vehicle on a frame rail. That’s great for cooling the relay, but it also exposes it to lots of water and salt. Since the relay is solid state and provides almost 40-amps to the radiator cooling fans, it can get quite hot. The frame rail is … Read More

P1489 and overheating 300M

 Fix code P1489 and overheating 300M Owners who have an P1489 and overheating 300M with trouble code  High Speed Fan CTRL Relay Circuit, here’s what to do. Remove the high speed fan relay and use a digital multimeter to check for power on the two terminals of the electrical connector. If you show power, reinstall the relay. Then ground the dark blue/light green wire at pin 69 of the PCM. The relay should click. If it doesn’t try swapping in a new relay or run a continuity test on the … Read More

P0480 Cobalt Fix

Fix code P0480 on Cobalt This vehicle has a 2-speed cooling fan. If you run into the P0480 code and find that the fan will only run on the highest speed, start by checking for a blown cooling fan fuse #1 in the underhood fuse block. If that’s ok, swap cooling fan relay #1 with the high speed cooling fan relay #2. Both relays have the same part number. Rest the PCM to clear the trouble code and drive the vehicle. If the low speed relay is bad, the swap … Read More

Overheating problems Cavalier

My Cavalier Overheats Owners of GM 2.4 engines may encounter overheating problems that drive them crazy. If you’ve checked the thermostat, water pump, and radiator and still can’t find the cause, pressure clean the heater core. That’s right, the heater core. This engine setup uses returning coolant from the heater core to open the thermostat. If the heater core is pluggled, the thermostat won’t open and you wind up with an overheating problem. GM wants the heat to get to the heater core first. If the heater core is plugged, … Read More

Overheating problems Crown Vic, Grand Marquis, Town Car

Fix Overheating problems on Crown Vic, Grand Marquis, Town Car Ford is reporting overheating problems with 2006-07 Crown Victoria, Grand Marquis, and Lincoln Town Cars. The vehicles run hot and experience poor cooling from the A/C. The problem is most severe at low speeds or while idling. You guessed it, the problem is with a bad electric cooling fan. The fix is to install a newer design, fan, part #7W1Z-8C607-B. © 2012 Rick Muscoplat   Save

Lower temperature thermostat

Should I install a Lower temperature thermostat No!!! In the good old days of carburetors shade tree mechanics would try to fix an overheated engine by either removing the thermostat or replacing it with a Lower temperature thermostat. It wasn’t a good idea then. It’s an even worse idea now. At best the low stat/no stat switch-a-roo was a temporary fix to a hot running engine. The engine ran ok because the choke would shut off at its normal range and the air/fuel mixture would lean out. The engine wouldn’t … Read More


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