Weird running hot issue

[pfarmer]

Trust me on this one... If it opens sooner the air never gets a chance to cool the fluid. Even with the fans running, which i assume they are, they never get the chance to cool the fluid because it is constantly moving..

I don't ever think the t stat is open always.

In my jeep when the motor is cool I can watch the thing get hot and right to half way and when it hits that point it opens and the cold coolant flows into the motor and then I see the temp drop. Our car the Computer manages all this electronically.

Note: when you are driving the higher rpm's turn the water pump. That is why when you are at a stand still the water pump is also pumping very little water. When the fans are working properly and you take off again from a stop, the temp goes back to normal because the radiator has cooled the fluid with the help of the fans and the t stat has opened because the engine temp has reached the point at which it opens.

If the T stat opens sooner and you are at a stop it will just circulate hot coolant.

So how does the computer connect to the thermostat?

If the car is at a stop, or moving, and the thermostat is open, it appears that the water pump will circulate water through both the engine and the radiator. The water pump besides circulation should do a fairly good job of mixing the cooler radiator water with the warmer engine block water.

Due to the simplicity of the system a temperature increase when moving from idle to increasing rpms. could be attributed to the location of the temperature sensor and related to the difference in water density between the cooler radiator and warmer engine block.

Perry

[pfarmer]

The reason I say fans or even the cooling ability of your radiator is because you say it moves up when you stop. When you stop, there's no air flowing past the radiator. That's what the fans are for and if those are working, then either what Tampa said or the ability of the radiator. Could also be an air bubble or air leak in the system.

Air in the system I would say could certainly be a factor and makes some sense depending on time at idle and the location of the temperature sensor. If at lower flow rates a bubble could form blanketing the sensor then it would take on the temperature of the thermo well it screws into as well as that of the air bubble which is in contact with the metal of the component and whatever water is present. Once a higher flow is established and the bubble is pushed away from the sensor then it would sense the termperature of the water which will change at a higher rate then the metal of the thermo well. Air in the rest of the system will have an opposite effect, that is the air will blanket the part being cooled and keep the water from being able to absorb the heat from the part. This can actually decrease the coolant temperature and raise engine temperature. Without an oil temperature indication (or block temperature) you would not see this increase.

Perry

[smockers83]

/ dissertation

[pfarmer]

/ dissertation

Experience

Perry

[Sentientbydesign]

Nice analysis, Perry!

[tollboothwilley]

Wow. That was a overload of info. I hope that you type 90 wpm.

[pfarmer]

Wow. That was a overload of info. I hope that you type 90 wpm.

Only on a manual Royal.

Perry

[azeiler]

I'm a little late to the party, but what fixed the problem?

[ddemier7]

Air in the cooling system. Re burp the cooling system.