Temp gauge sensor solution

I have a 1996 with a 1998 engine swapped in. I had a problem with the location of the temp senor at the back of the head since the newer head has no hole to accept it. I went to home depot and bought a brass 1/8" pipe thread coupler and JB welded it to the flat spot on the head where the hole would normally be drilled. I filled the fitting with oil after the JB dried for a day in order to transfer the heat from the head to the sensor. I made a jumper wire from the firewall ground directly to the top of the brass fitting to ensure a good ground. Once installed the temp reads right at 210 during normal operating just like it should. I have not tested this thoroughly yet but all indications so far are that it is a good easy work around for those with this type of problem.

similar to installing a transducer inside a fibreglass hull, epoxy a pvc fitting to the bottom of the hull, then fill with water, then install transducer so there's continuity.

Good anology. The 1/8" pipe thread coupler is the same thread pitch as the sensor itself so it actually screws into place and holds it tight the oil is there to help transfer the heat from the head to the sensor. I would not use water since it may evaporate, there may be a more suitable liquid to use but the oil seems to be working great and it is readily available. I don't know how other people have solved this problem but it works really well so far and I figured it might help a brother out in the same situation.

Nice!

Wouldn't it have been a lot simpler just to extend the sensor wire up to the t-stat and splice it in there? You would have, should have a proper temp signal. At least that's what I gleaned from the schematic.

Are you suggesting drilling and tapping a new hole in something and using the sensor up front? I guess you could do that. I would not say that was a simple way to do it but if the sensor is in the coolant stream and it doesn't leak then I'd say that is a good option as well. I was looking for a simple cheap and effective way to fix this problem. Assuming joe mechanic has no tools my method cost less than 15$ probably less than 10$ really and works fine. Your idea takes a tap, a drill press & bits and cutting the harness dissasmbly, reassembly. Sounds like it will work but If I can save myself the time for the same result I'm going the easy way.

No, not an additonal sensor, just the one up front and taking the wire from the rear, extending it to the front and tapping into the existing front wire. So it works like the later models. One sensor for gauge and ECU.

AHHHHHHHHHHHHHHHHHHHH.

I did not know if the signal from that sensor would work but if it produces the same reading on the gauge then yeah I'd say that would work fine too. I'll have to backprobe those two sensors and see what the values are for the temp and see if they differ. Good idea, only bummer there is you have to do some harness splicing but not too much.

The sensor on the t-stat housing has 2 wires in it. Which wire would you need to tap into for the gauge to work?