Originally Posted by Stx221
The temp sensor that the arrow points to is for the ECM. There is another sensor somewhere for the gauge, but I don't know where it is located based on memory. As far as I know, the ECM and the gauge do NOT get a reading from the same sensor.
I can find the location of the other temp sensor for you this weekend when I have access to my repair manual. I wonder if the sensor for the gauge is off slightly, but the ECM is seeing the correct temps? Does the boat run well?
For what its worth, mine runs at approx 140 degrees all day every day...
Correct, the sensor with the arrow in pic above is for the ECM. 2 wires, yellow and black.
The sensor I replaced is for the guage for sure. It does seem to me that sensor will always read a colder temp than the ECM sensor. Not sure why they chose to have those sensors where they are because they will never read the same water temp IMO.
The boat runs perfect. I will take a infrared temp gun out with me next time to check various engine temps in various locations on the engine.
Maybe some other LT-1 owners can see if their guage sensor is in the same spot, and post what your engine temp is when running the boat. Stx221, nice to know you're running 140 all the time....sounds about right for guage reading. I bet the actual engine temp is closer to 160 because of the top t-stat. Perfect temp.