Two months ago the car started giving the "I'm too hot!" alarm, an insistent pinging that attached to my brain stem.
The mechanic said that with no leaks and plenty of fluids, I must have a faulty sensor, which he did not know how to replace. I tried to make the car overheat by idling it for an hour--a car is at its hottest when idling. No leak, no heat. Guess the mechanic was right. Drove the car again.
I was going to have it fixed, but then I became addicted. I would get in the car and drive for a couple of minutes just to hear the
Finally it came time for vacation and my wife, who has no tolerence for substance abusers or sonic abusers insisted that the pinging be remedied. I took it to another mechanic who replaced the sensor.
That mechanic said it was low on fluid. He added water. Water poured out through the radiator, just as fast as he poured it in.
Replaced the radiator. $300.
He tested the temperature by hooking a monitor into the car's computer. The car was really hot. No faulty sensor.
Thermostat was bad. Replaced.
Radiator cap would not hold pressure, which meant that the fluid got hotter than it should. Replaced.
The only other part of the cooling system outside the engine was the water pump. The coolant is pumped into the engine and heats up, then is pumped through the radiator, a big heat sink that allows the heat to radiate into the air. The radiator works better when the car is in motion, because there is air rushing over it and carrying the heat away. But if the water pump is broken, the coolant does not circulate out of the engine so the heat will not radiate away.
Bingo! (Or maybe Pingo?)
The water pump is like a fan that blows coolant through the system. My fan blades were slightly loose on the fan's shaft, so when the fan was going slow--when the car was idling--water was pumping, but when the fan sped up, the loose blades would not turn because the shaft was spinning so fast.
So the coolant was circulating through the engine at slow speeds, but not at fast speeds. That explained the strange fact that my car got hotter when driving than when idling.
Replaced the water pump. The problem was fixed. We left on vacation a day and a half late and about 250 more dollars short.
Now where am I going to find another