I'm planning on installing a coolant temperature gauge and need to find a location for the 1/8 NPT sensor. I was planning on using the block drain plug, but the size is BSPT 1/4-19 and is going to be too small for an adapter for the 1/8 NPT.

Anyone have a suggestion on where I can put the sensor? Ideally somewhere in the block to measure coolant temperature inside the engine....and not a hose that will only see flow when the thermostat opens.

 

Maybe you can get a fitting to replace the original sensor that will accept two sensors.

It's difficult to tell from the crude drawing, but the sensor appears to be near the bellhousing.

 

Thanks for the idea, but I may have spoke too soon. I found an adapter for the 1/8 NPT sensor to fit in the block drain port. I just assumed it was too small but that's what I get for assuming.

 

Unless the sensor is put where the coolant is free-flowing it might not give an accurate reading. Putting a sensor in the block drain port, it may be somewhat shielded if it doesn't protrude far enough into the coolant passage.

 

Thanks for the reminder. The sensors I'm receiving look long enough in the photos to compensate for the adapter length and still have some left to protrude into the passage. The other potential issue is that it is too long and may partially block the coolant flow. I'll check it prior to installing and make any adjustments.

 

I received the sensor and it will definitely protrude far enough into the coolant passage in the block drain port. I tried to install it on the driver side and there is no way of me even seeing the drain port, let alone accessing it due to the AWD transfer case and components. So I tried on the passenger side and while I can see it, I just couldn't figure out a way to get a tool on it. There is not much room at all in this area on either side.

I thought maybe I can access it if I removed the wheels but I noticed the inner wheel housing doesn't have removable access panels.

Has anyone accessed either of these block drain ports (driver or passenger) and how did you do it?

Or, what alternate locations are available where I can install the sensor to give a reading of coolant temp in the engine?

 

After looking around the coolant lines for a location, I found a nice flat surface that just might work. If I can drill and tap this location (see photo) with a 1/8 NPT for the sensor, I think the sensor tip just may hit that water passageway of the hose that leads to the throttle body. My assumption is that this passage has coolant flow while the thermostat is closed so as to warm up the throttle body on a cold day....thank you emissions. So in theory the sensor will be reading the coolant temperature of coolant flowing in the engine regardless if the thermostat is open or closed.

Any thoughts??

 

Here is a photo of the sensor in that location.

 

I don't see an issue with that location.

I am curious though- why do you want an additional coolant temp sensor? You could just use an OBD2 gauge or a bluetooth app to view those readings

 

I was just wondering that too.

My ScanGauge shows me Coolant and ATF Temps as I drive

 

I've tried the Torque Pro OBDII setup and it was never consistently working properly. I was needing to unplug the connector, restart the phone, and my dash would have some warnings come up every now and then. So the OBDII just didn't work for me as it needed babysitting. I've already installed an oil temp sensor in the oil filter housing, a transmission temp sensor in the trans pan, and the coolant gauge is the last one to install. These will be more permanent than the OBDII and without the connection issues I was having.

 

Try a dedicated ODB tool instead of using your phone. If you really want to monitor temps that bad then a dedicated solution is better where you can leave it plugged into your ODB2. I'm sure amazon sells many of those. I'd try that before drilling into my cooling system.