I have a 96 jeep Cherokee sport that the PO swapped a 97+ motor into. I THINK it's a 99.
Because of this my thermostat gauge doesn't work. I've made this thread before but I need a thermostat gauge, I was going to buy a scan gauge tool but I was thinking I can I just run a secondary aftermarket gauge by wiring tapping into something else. Is it possible for me to drill into the therm housing and putting the aftermarket sensor in there? Would it work? What size bit would I need?

Bump.
What if I splice in a longer wire from my dash gauge and drill a bung for that sensor in the t-stat housing?
It's starting to make me uncomfortable not knowing my temp when I have a slight coolant leak

the temp sensor for the gauge is on top of the cylinder head way in the back on driver side. make sure its plugged in before you go drillin holes

Maybe if you read my first post you'd understand what i'm saying.
In 97+ they changed the sensors into 1. There is nothing for me to plug that plug into.

Bump.... Would I get more replies in oem tech?

I would not put it infront of the t/stat as thats measuring coolant temp on the cold side (radiator side) of the system... where as with the factory setup it measures the hot side (engine side) of the system. But on the newer ones its only monitered on the cold side of the t/stat, so it should work... It just may not show full temp as it exits the head/block....

Get one of the 97+ t-stat housings, has a threaded hole already, get a temp send that will work and splice into the existing temp sensor wire and extend it,

I personally have found the housing to be too thin to handle drilling into it and trying to tap it. I think it would break.
X2 on the finding a threaded housing.

Won't the thermostat housing with the factory hole from another year XJ bolt into the same place on all years of the 4.0L?

Edit: I guess what he said:
The base and mounting bolt look the same, though I've never actually seen it done. I would think it would work the same.

It should bolt up with no problems... I know my 2000 t/stat housing fits my 91 cyl head... its a 7120 HO, I would assume all HO would interchange, but Don't know about renix...

I have drilled/tapped a couple Renix 4.0L t-stat housings for a secondary temp sender with no issue.

Let me explain this one more time. 96 and down engines had 2 different sensors for measuring coolant. One that gets sent to the ecu and one that gets sent to the dash. In 97+ they changed that into 1 sensor. The previous owner didn't didn't anything to the harness to accommodate this so I have one plug off my harness that has NOTHING to plug into (temp gauge)
I DO have a threaded hole with a coolant temp sensor for the ecu on the front of the t-stat housing. You telling me to get another housing won't make a difference.




This photo is of my t-stat housing. I have a sensor there for the ecu





This is the wire off my harness that leads to the temp gauge there is nothing for me to plug this into.

Can I extend this wire and drill a hole into the housing to accommodate both sensors?
To the last poster what did you do exactly?

that looks like the temp sensor that plugs into the manifold to me.....

What manifold are you talking about?

Please send me a picture of what you're talking about so I can prove my point to you