So a while back I snapped my temp sender off in the head and could not drill it out so I recently picked up an adapter that goes in-line with my upper radiator hose. I got it wired up and it works. It'll go up to 210 but it seems when the Thermostat opens, it will quickly jump to the red even though the engine isn't overheating. What could be causing this to happen? Knowing my luck, it is something super simple.

 

You need a ground on the body of the sensor, in the factory location it grounds through the thermostat housing. You might find a tapped hole on the glowshift adapter you can run a little wire to ground with.

 

well when i first installed it, the sensor wouldn't read at all. It only started reading anything when i wrapped wire around it and grounded it to the compressor. Was wondering if maybe it's also somehow reading the temperature of the adapter itself.

 

Good to hear about the grounding wire.

As far as it reading the temperature of the housing it's similar to the factory mounting in that it's screwed into an aluminum housing and the probe should be immersed in coolant unless you have an air pocket in this location as it is likely the highest point in the system. The air pocket might explain the sudden needle movement when the thermostat opens.

 

i can try and shake the hose and try to get any air out. I did lay the sensor sideways to try and prevent that from happening. Maybe it has to be perfectly vertical or something.

 

There were some air bubbles in the hose but it's atill moving to red after about 5 minutes

 

I don't think the upper hose is a good location for that sending unit.

 

I agree with cruiser. If you snapped off the existing location, just replace the thermostat housing with a new one. Fairly easy fix.

I imagine you've verified the temperature with an IR gun or other thermal measurement device?

 

I have and it's reading a lot lower than the gauge is of course. Also the temp sender goes into the back of the head, not the thermostat housing. You're probably thinking of the temp sensor that goes there for the computer itself to read.

 

starting to think that as well. maybe the lower rad hose would be better? either way im gonna have to keep it in until i get a replacement upper hose