Ok, so I'm running a megasquirt ECU that is connected to my stock coolant sensor (S5), and I also have a Defi coolant gauge with the sender in a hole I made in one of the bolt holes that the air pump used to mount to.

most of the time the reading on the gauge and the reading on my laptop are about 5 degrees off, and I was just wondering which one I could trust and why they might be different?

I assume the defi is more trustworthy, but would buying a new stock sensor help? my coolant fan is activated by my ecu which uses my stock sensor (which reads lower) which is why I'm a little concerned.

thanks guys.

 

You should be fine, just dont go past 210.

 

5-degrees difference is not going to hurt anything.
The stock electric fan used to trigger at 225F on my SPI water temp gauge.


-Ted