Adjustable Temperature Sensor

[Mudderoy]

I've been battling running hot on the freeway for years. It happened just after the 4.5" lift and 32" tires.

I did have several issues with my cooling system and in the seven plus years since the lift I have replaced everything in the cooling system at least once and somethings twice, or thrice! {cough} radiator {cough}

Recently Carves recommended I use an external temp sensor. I was looking at plumbing the heater core line and installing a mechanical sensor, but this Engine Watchdog TM-1 makes mechanical contact with the metal under a bolt and reads the temp of the metal. I attached it to one of the thermostat housing bolts.

That was a month ago, at least. I have noticed that the temp variance between the TM-1 and my OBDII Torque app is something 30 degrees. HIGHER!! on the OBDII.

No not the gauge directly from the computer.

Since the temperature sensor changes resistance with heat I figured that I could add a variable resistor and adjust the resistance (in ohms) that the computer was reading.

Today I wired a small 1k ohm variable resistor in.











I'm going to run this and see how close I am. I'm concerned about this very small potentiometer handling the heat of the engine bay. I may take another, adjust it, read the resistance then replace it with a fixed 5 watt resistor (or two).