Temperature gauge with a LS 1 motor

[David623]

My temperature gauge barely gets off the cold mark, temperature needle should be halfway on the gauge and mine barely gets past the cold mark. I have a 1999 LS 1 and we hooked the [original 350sending unit] into the LS cylinder head we retaped the threads to accept old sending unit.
I have checked and temperature 190 degrees when warmed up, so I just don't know its not reading correct [meaning needle at halfway point]
Any help would be appreciated.

[jjzepplin]

I would also like to know.

[Accelo]

Did you tape the threads? Should be installed dry.
Check the resistance between the block and the sensor when cold and when hot.
Should be able to find the issue from there.

[David623]

Installing dry do you mean without using tape?

[Accelo]

Yes, exactly. The tape can sometimes insulate the sensor and affect the grounding.

[SeventyOne]

Sensors have different ohm ranges which would lead to the engine being at the correct temp but your stock gauge not showing the correct temp.

Compare the LS gauge specs to a stock gauge and i bet you find your answer.

[David623]

Thank you for the information, yes we did use tape and that sounds like the reason it would not read correct.

[dmjlambert]

A couple wraps of teflon tape will not prevent the threads from cutting through and making good contact. The normal operating needle position is not halfway point, it is lower. This picture from another thread is an example from a gauge at normal operating temperature.


If you're not reading somewhere around there, I suggest post a picture of the sender. This example from another thread is what the sender should look like.