This sounds strange, but my car's engine won't heat up. I bought the car new in 1994 and this problem started a couple years ago. It is a 1994 Corsica with a 6-cylinder.
A couple winters ago the heater began putting out lukewarm air. I pulled the PCV valve out of it's hole and noticed milky looking moisture around it, but the head gasket is not leaking, nor is the moisture getting into the oil. Obviously, the moisture is coming from the crankcase because the engine is not heating up enough and it is creating condensation in the crankcase. I can drive a hundred miles on the highway and the engine absolutely will not heat up. If I accelerate hard up a hill the temperature gauge will rise, but when I level out and decelerate it quickly goes back to abnormally cool again. I replaced the thermostat with a Duralast 195 degree thermostat and what happened next was weird. After replacing the thermostat I started the car and watched the temperature gauge (the gauge works) and the gauge went three-quarters of the way up (like it did when the car was new), then fell when the thermostat opened (like it did when the car was new), and the heater put out good heat until I shut the engine off and restarted it. Once I restarted the engine, the engine absolutely would not heat up again, the temperature gauge stayed VERY low and the heater would not put out more than lukewarm air. Thinking that the new thermostat was defective, I replaced it with another new one rated at 195 degrees. It did the exact same thing that the first one did- the engine heated up and the heater put out hot air until I shut off the engine and restarted it. After I restarted the engine, and every time thereafter, the temperature gauge stayed very low and the heater put out lukewarm air. For some reason, I went and bought a third thermostat and installed it. The exact same thing happend again. The third new thermostat caused the engine to heat up but would not do it ever again once the engine had been shut off and restarted.
I have replaced the water pump and flushed the radiator and heater core with no results. This car's engine absolutely will not get hot. (except during the summer it did) Does anyone have any suggestions as to what is causing the problem? I might mention that my EGR valve went bad a few months ago and I plugged the hole beneath it with gasket material to avoid spending almost
300.00 for a new one, but I don't think the EGR valve would have anything to do with the engine running cold. Thanks.