I did that on mine without any issues. If we're talking about the same plug?! The sensor is not mounted on the last pic but it is now. Was checking the temp gauge on a long run at the easter days and it was max. 190° in a traffic jam. Edit: always read carefully I used the shown plug on the passenger side and deleted the original temp sensor for using the temp sensor of the shown gauge.
I'm sure Tommy will weigh in here, but yeah the back of the drivers side head is the place to sink an additional sending unit. Tommy says heat and candle wax make this job simple, I had a devil of a time taking mine out. Get good access before you even start..
And make sure you use the correct size removal tool. Since I have MANY old oil pan drain plug removal tools for the pretty much older vehicles I just use the proper square size. ONE thing you need to do is NOT round out the plug. That can make it a very laborious job. Just ask Rhett he knows. Tom T.
I used Kroil, heat gun at 1150F and air driver on lowest setting and went back and forth until it broke loose. I have mechanical temp sensor in the back, and FiTech EFI controller sensor reading the front, and the delta is 3 degrees at all temps from cold startup until 210 (idling and tweaking in the driveway, with low airflow through the old 4 blade Sopwith Camel propeller.)
Dang, sounds like a bear. Good thing I asked! What's the wax procedure and what do you use for a heat source? Hopefully the tool is available.
The heating will help break the bonds both chemically and mechanically, and then the wax can "wick" into the threads as it cools and is reheated, and the "back and forth torque" will assist in the breaking of the bond and facilitate further wicking action of the penetrant/lubricant. And all of those things add up to free the fastener. Sometimes wax works better in the heated applications than oils, as the oils will often burn off faster than wax. It took years to get stuck, so a an hour or even a few days are better than rushing and having to drill, chase shavings, retap, rethread or weld a bolt to the bung plug, etc.
I cut my upper radiator hose, and placed one of those adapters in between.. Works good, but not as "clean" as mounting the sending unit in the back of the head..
And I use one like this for oil temp and oil pressure.. Have 2 electric gauges in the car, and 1 mechanical in the engine bay for reference.. There's 4 outlets in it, and I goes in between the block and oilfilter..
On my nailhead, I used a 3 inch nipple, a cross, and allows the oil pressure light, oil gauge, and an oil pressure switch to enable/disable fuel pump relays (two in parallel for redundancy). Just another way things can be done. I used a headlight connector for the pressure switch, but needed to twist all the blades a bit (all same pitch) so the connector would grip. I did not want two or three connectors, but it would have been fine to do that. (The oil light sender looks closer to the manifold than it is.) 20171220_224122 by TrunkMonkey posted Dec 22, 2017 at 3:22 PM 20171220_22413 by TrunkMonkey posted Dec 22, 2017 at 3:25 PM 20171220_224419 by TrunkMonkey posted Dec 22, 2017 at 3:22 PM 20171220_224105 by TrunkMonkey posted Dec 22, 2017 at 3:22 PM 20171220_224053 by TrunkMonkey posted Dec 22, 2017 at 3:22 PM
Thanks for all the ideas guys. I did something similar before with the oil gauge. Think I might cowboy up and try and wrench out that plug on the head for the water temp. I've also seen a port on a Chevy thermostat housing before as another possible option.
