OVERHEATING - A Common Complaint?

Searching on the web quickly reveals that many people have experienced problems with their PT Cruiser overheating. Really? Like the brake problem, this was news to me. My temp gauge had never moved from the normal in all sorts of driving or pulling the trailer. Then, one nice Spring day, my 2008 PT Cruiser overheated. It wasn't even an exceptionally hot day. The car was idling in the driveway, and suddenly the radiator was steaming. I shut the engine off, and went to work on something else until it had a chance to cool a bit.

The radiator level was not low, other than the little bit that steamed out of it. The car started, ran fine. It came up to temp normally. The thermostat opened, and water started flowing through the radiator. I put the cap back on and took it for a drive. There was no sign of a problem, it didn't overheat at all. Back in the driveway, with the engine idling the problem soon became obvious. The cooling fan never switched on, and the temperature started to climb. As long as the car was moving, enough air flows through the radiator to keep the engine cool. The cooling fan may have been broken for a while.

It is possible to just replace the fan motor, but when checking for parts, it was much more common to find the entire fan, wiring, and relays as a complete assembly. In most cases replacing just the broken part is less expensive. However, with just over 100,000 miles on this car, those relays have seen a lot of action, and could actually be what is keeping the fan from turning on. In this case, it seemed smarter to spend a few extra bucks and replace the entire fan assembly.

The fan assembly is attached to the radiator with six bolts, two top, two bottom, and one on each side. Make sure you are removing the bolts that attach the plastic fan to the radiator, not the radiator mounting bolts. They are all 10 mm wrench size. With the car on a set of ramps, drain the coolant and take the bottom radiator hose loose from the radiator. Disconnect the wiring harness connector that goes to the chassis. This connector has no additional locking tab, just a stubborn latch that had to be pried with a screwdriver before it would release. The fan assembly comes out the bottom with a few wiggles. Slide the new fan assembly into place, making sure the wiring connector is at the bottom. Start all bolts before tightening anything, then make sure all bolts are tightened. Don't overdoo it! The fan frame is plastic. Reconnect the radiator hose, wiring connector, make sure the radiator drain is closed, and refill the radiator.

That fixed it, and once I heard the fan running that does seem like a sound I have not heard in a long time. For the next few weeks it's a good idea to keep an eye on engine oil and water levels. Watch for signs of oil in the water, or water in the oil. The concern with any engine that has overheated is a possible cracked head or head gasket problem. In this case, the car did not seriously overheat, it didn't boil all the water out or anything like that.

RELATED AIR CONDITIONING ISSUES

This fan failure likely went several weeks or even months without being noticed. The engine will not overheat as long as the car is getting some airflow through the radiator. Cars that are only driven for short trips or never get caught in traffic, won't overheat, but will begin to have other expensive problems if the fan isn't working properly. The air conditioning system uses the same cooling fan. Running the air conditioning system with low airflow through the radiator can damage the compressor.

After reading the horror stories on the web, it is fairly obvious the cooling problems many people experienced are made much worse by expensive damage to the air conditioning system or engine. It sure seems like most of this bad publicity could have been avoided by a better quality fan assembly, or a logging a fan failure trouble code.