Temp Gauge Issue

[yeahmag]

My temperature gauge is not working normally. Prior to my head gasket and thermostat replacement I never got any temp readings on the gauge. I found the previous owner had effectively no thermostat in place during the repair...

I cleaned the passages in the head, block, added a MM thermostat, and replaced the head gaskets. I used a teflon based pipe sealant (Loctite 567) on the the threads for the sender and adapter in the head. My gauge is funcional now, but I get fairly rapid temperature swings on the gauge. Faster than what would likely be happening in the engine. For example, a swing from 160F - 200F in a few seconds...

Is it likely that the sealant is the problem or something else?

Thanks

-Aaron
1972 Ranger 33

[Wisakedjack]

I had similar situation with my engine. The issue was having teflon tape on the sender. The sender's body is the ground, so it needs good contact with the engine body. Try to clean sender threads and install it again without any tape. Hope this helps.

[JOHN COOKSON]

One ohm meter probe on the body of the sending unit and the other probe on the head. S\B zero ohms, of course.

ex TRUE GRIT

[sastanley]

The gauge sender is just barely downstream of the thermostat housing. I agree with Alex with maybe pulling the sender and screwing it in again to see if the ground and readings improve but doesn't leak.
Mine swings pretty fast, but maybe 6-8 seconds from 170-150 as the t-stat opens.