CAT 312 Water Temperature Sensor

[Pepe]

Just wondering if anyone has had a faulty water temp sensor & if faulty would this cause the guage to go up & the buzzer go off after 1/2 hour of running. Coolant is OK on inspection, thermostat fine & coolant not overflowing to the holding tank?? any thoughts.

 

[Nige]

Just wondering if anyone has had a faulty water temp sensor & if faulty would this cause the guage to go up & the buzzer go off after 1/2 hour of running. Coolant is OK on inspection, thermostat fine & coolant not overflowing to the holding tank?? any thoughts.

Highly unlikely to be the gauge or sensor if it takes that long to max out.
Try using an infra-red heat gun and when the buzzer is going off shoot the temperature of the hose from the thermostat housing to the radiator and the hose back from the radiator to the engine.
Also please post a Serial Number. It mkaes it easier to find information.

 

[Pepe]

Thanks Nige. I will buy a infra-red heat gun & check. Serial No: 8JR01832

 

[Pepe]

Highly unlikely to be the gauge or sensor if it takes that long to max out.
Try using an infra-red heat gun and when the buzzer is going off shoot the temperature of the hose from the thermostat housing to the radiator and the hose back from the radiator to the engine.
Also please post a Serial Number. It mkaes it easier to find information.

Hello Nige I put the infra red gun on my CAT 312. After half an hour running. Readings 1/. Thermo to Radiator 91 F- 96F 2/. Back to engine hose: 113-107 F. In 1 hour reading was 1/. 32-34 C & Back to pump 43C...... The Guage stayed just under 1/2 level. Im wondering what have I done?? as not overheating after an hour running......I will need to run it longer to see id any changes I guess

 

[Nige]

After half an hour running. Readings 1/. Thermo to Radiator 91 F- 96F 2/. Back to engine hose: 113-107 F.

In 1 hour reading was 1/. 32-34 C & Back to pump 43C

I’m sorry those numbers make no sense. With a measured temperature on the return line from the radiator to the engine HIGHER than from the engine to the radiator that would indicate the radiator putting heat into the coolant not taking it out.

 

[Pepe]

I’m sorry those numbers make no sense. With a measured temperature on the return line from the radiator to the engine HIGHER than from the engine to the radiator that would indicate the radiator putting heat into the coolant not taking it out.

Thanks. My next move will be clean radiator & oil cooler in front as hard to get the bottom in between. Fan OK & Belts. Can you tell me is there any pressure when I disconnect the oil cooler or can I just unbolt & catch oil? as have no manual.

 

[Nige]

My next move will be clean radiator & oil cooler in front as hard to get the bottom in between.

Being made up of so many indicivual elements those cooling packs are impossible to clean when installed. You need the whole thing on the ground and disassembled before you attempt to start cleaning otherwise you are wasting your time.

Did you carefully read my comments above in reference to your temperature readings.?
I will repeat, they make no sense because at face value they show that the radiator putting heat INTO the coolant instead of taking it out, which by all the known laws of physics is impossible.

 

[Pepe]

Being made up of so many indicivual elements those cooling packs are impossible to clean when installed. You need the whole thing on the ground and disassembled before you attempt to start cleaning otherwise you are wasting your time.

Did you carefully read my comments above in reference to your temperature readings.?
I will repeat, they make no sense because at face value they show that the radiator putting heat INTO the coolant instead of taking it out, which by all the known laws of physics is impossible.

Yes I understand the cooling in & out not good. Ok will take both out.

 

[Nige]

Yes I understand the cooling in & out not good.

It's not just that. The temperature of the outlet is higher than the temperature of the inlet. That ought to be physically impossible.

I thought that maybe you had somehow juxtaposed the two sets of readings and put "inlet" where you meant "outlet" and vice versa. To be clear the inlet to the radiator is the hose from the temperature regulator (thermostat) housing shown by the red arrow and the outlet is the hose from the bottom of the radiator to the water pump shown by the blue arrow. This illustration is from the side looking backwards from the front of the machine.

After the engine has warmed up the red hose should always be significantly hotter than the blue hose.

 

[Nige]

Attached the R&I instructions for the oil cooler and radiator.