M35A2 Temperature Gauge Issues

[glcaines]

I decided to take my M35A2 Kaiser Jeep for a ride a little while ago. Deuces seem to run better when exercised. I noticed that the engine temp gauge was reading a little low after about 10 miles, and by the time I got back it was reading at the minimum temp. At first I suspected low coolant level and the resultant temp sensor not being in the coolant. However, the engine (Hercules multi-fuel) was not overheating. I have not checked the coolant level yet, as the engine is still too hot to remove the radiator cap. Now I know what I'll be working on tomorrow.

[MARTIN CROSS]

Hi

I have added 'water wetter' to mine as it reduces engine temperature. Frosts Automotive sell it as do Halfords.

It may also be a bad connection. My fuel gauge has always read low but going over a bump made it read correctly for a while!

Good luck,

Martin

[Degsy]

Sounds like a gauge or sender unit fault or could be in the wiring between the two.

[glcaines]

I pulled the sending unit and put it in boiling waterwhile hooked up to the truck. It read correctly. After re-installation, it again reads minimal temp while driving and fully warmed up. I'm now suspecting a faulty thermostat that is stuck open. I think I will go ahead and replace the thermostat. This vehicle is over 40 years old and I don't know how old the installed thermostat is. I purchased the truck from the U.S. Army last summer and this is the first time I've had any cooling system issues. Actually, the only problem I've had with the truck is that I lost 5th gear in the transmission after driving somewhere around 1000 miles. I swapped it out with another used transmission. I replaced the clutch and pressure plate at the same time since the transmission was out, but it really didn't need a new clutch.

[Degsy]

Since you have proved the sender unit and gauge ok the thermostat could be the culprit , another fault could be the rad cap, due to the age of the vehicle and the minimal cost involved may well be worth replacing.

[glcaines]

Since you have proved the sender unit and gauge ok the thermostat could be the culprit , another fault could be the rad cap, due to the age of the vehicle and the minimal cost involved may well be worth replacing.

 

I don't think it is the rad cap causing the problem, but I agree that it should be replaced due to the age. It looks to be very old, perhaps even the original. I have one on order. Thanks.