Engine Cooling problem
2006 Chrysler 300 6 cyl Automatic
had this car in the shop twice, they replaced radiator, thermostat and checked everything concerning this problem. Its back in the shop now. The heater blows cold air when it over heats, the lower radiator hose is barely warm to the touch when it overheats. The radiator fan seems to be working. Could it be the radiator cap? Can I remove the thermostat permanently? Last summer, I could drive this car hundreds of miles without it overheating, and sometimes I couldnt drive more thana mile or two before it happened. Do water pumps work intermittently.
Water pumps can develop loose impellers, but that's more of a Volkswagen thing. Poor circulation will result in cool radiator hoses, but the gauge will read " hot". If the gauge reads low, what makes you think it's overheating? No engine will overheat in only a couple of miles. Some of the symptoms suggest a leaking head gasket. Look for bubbles in the overflow reservoir. If the coolant is cold, you know it's not overheating.
Do not remove the thermostat. In some cases, that will cause overheating because the coolant won't stay in the radiator long enough to cool. More commonly, the engine won't reach operating temperature. Parts won't fit right leading to rapid engine wear, and the fuel system will not go into " closed loop" and fuel mileage will go way down.
The pressure cap simply allows system temperature to go above 212 degrees without causing the water in the coolant to boil. It doesn't CAUSE the temperature to rise.
June, 13, 2010 AT 1:21 PM
Do not remove the thermostat. One of the first steps in a repair to the cooling system should be test and make sure the thermostat is working properly and replacing it if not. So you replace if needed. Considering I'd like a new thermostat every now and then in my car.