Water temp guage install

[isaacucv]

I found a new place to put the coolant temp sending unit. Well new to me anyway. I searched this site and found people put them at the back of the pass side head, but that seemed like a lot of work to get to that cover plate and go buy a new threaded one. So I put it on the back of the drivers side head where the stock coolant temp sensor(yellow and black wires) mounts. I went to the hardware store and got 1/2" brass fittings. I used a "T" and a nipple. It cost me about $8 and took about 10 minutes. I also installed an oil pressure guage. Im pretty happy with the way it came out. I will put pics up tomorrow.

 

[Blue2actual]

eagerly awaiting your pictures! I've got the parts to do it, but haven't done it yet.

 

[dstang97]

Would the gauge get the same reading as it would be in the cylinder head? I think it would read a little different because it would be pushed out from the block. Hopefully someone will chime in.

 

[isaacucv]

The fresh yellow wire that goes to the far end of the T is the guage temp sensor. The close side of the T is the stock coolant temp sensor(yellow and black wires). The only thing I had to move for install was the air filter, easy. Don't use teflon tape, the sensor has to ground to the block. Put the nipple in the bottom of the T first, then screw that assembly into the head. Make sure its tight, these brass fittings are an interference fit, which is why you don't need tape/sealant. Turn the T so there is clearance for the 2 sensors and assemble them to the T.

 

[isaacucv]

Would the gauge get the same reading as it would be in the cylinder head? I think it would read a little different because it would be pushed out from the block. Hopefully someone will chime in.

Yea I thought about that but I think it will be ok, as long as the coolant is still flowing through the block. I didn't drive it yet but when I do I will keep track of the guage readings and we can compare.

 

[DokWatson]

What are all the thread sizes of the T? I want to do this eventually for both coolant temp and oil pressure.

 

[isaacucv]

What are all the thread sizes of the T? I want to do this eventually for both coolant temp and oil pressure.

The T and the nipple are 1/2" for the coolant temp sensor. As for the oil pressure, I put the sending unit right on the oil cooler line by the little valve on the radiator where the oil lines come up. If you go this way, don't forget to open the valve.

 

[gvaneck]

I put the the temp sensor in the same place you did but did not use a t so I have the dummy light. Seems to be working well, what have your temps been reading?

 

[lavarok]

So I put it on the back of the drivers side head where the stock coolant temp sensor(yellow and black wires) mounts.

The sensor you t-ed is not for the dummy light. It is for the glow plug controller. At least you put a "T" in so the glow plug module can still function as intended. However, I am not sure how accurate the reading may be with the "T" installed.

The sensor on the driver side front of the head is where the dummy light gets the signal. It has 1 wire, not two, and is to the left of the front most glow plug.

On my camo M1009, I replaced the stock sensor with one for a gauge and eliminated the dummy light altogether. I used the STE ice connector to hold my gauge and tied the diagnostic port up under the dash.

I put the the temp sensor in the same place you did but did not use a t so I have the dummy light. Seems to be working well, what have your temps been reading?

I think you mean the front of the driver head otherwise you better recheck as you will have issues with your glow plug system.

 

[DokWatson]

I think he miss-spoke and meant passenger head. He has it in a place that should work. Its where the fast idle switch gets its reading, ought to work in theory.

 

[lavarok]

I think he miss-spoke and meant passenger head. He has it in a place that should work. Its where the fast idle switch gets its reading, ought to work in theory.

Not sure if OP meant passenger or driver side, I was going by the color code of wires and general location he mentioned.

The sensor with yellow and black wires is definitely the temp sensor for the glow plug circuit and fast idle/cold advance. Personally, I would not T off this location.

The bigger problem I see is that gvaneck said he used the same spot as the OP for a gauge sensor without a "T". By doing this ( if he did ), he has messed up his glow plug and cold advance circuit. I would suggest putting the original sensor and yellow/black connector back the way it was and using the temp sensor location I mentioned two posts back.

 

[DIESELGREEN]

Lavarok... Thought of an idea. Would using a tee fitting setup for the coolant temp sensor at the factory dummy light location work? (as in adding the temp sensor and still retaining the dummy light switch)...or would that affect the functionality of either sensor? Just a thought. I would prefer not to rely on just a warning lamp to keep tabs on my cooling system.

 

[isaacucv]

To clarify, I did put the sensor on the drivers side rear of the head. I mis spoke in saying coolant temp sensor. I should have said glow plug sensor, thanks to lavarok for pointing that out. That said, everything is working well. The truck started and idled perfectly in the 20's this morning. After idling for about 30 minutes, the temp guage reads about 140deg.

 

[gvaneck]

lavarok, I misread his first post last night when I posted, I did put mine in the drivers front of the block. I would have know there would have been a problem with the glow plugs/fast idle by now. I've had that temp gauge there for 9 months.

 

[lavarok]

Lavarok... Thought of an idea. Would using a tee fitting setup for the coolant temp sensor at the factory dummy light location work? (as in adding the temp sensor and still retaining the dummy light switch)...or would that affect the functionality of either sensor? Just a thought. I would prefer not to rely on just a warning lamp to keep tabs on my cooling system.

A "t" should work in theory in either location. However, if you have a temp gauge installed you really don't need the temp dummy light. Personal preference will decide how you proceed. I would (and have) install(ed) the gauge and leave the dummy light disconnected.

lavarok, I misread his first post last night when I posted, I did put mine in the drivers front of the block. I would have know there would have been a problem with the glow plugs/fast idle by now. I've had that temp gauge there for 9 months.

Very true! Good to hear!

 

[DIESELGREEN]

Thanks for the input, lavarok. Another upgrade to be checked off my list.

 

[rnd-motorsports]

Also anytime you put a pipe and tee or just a tee in, neither sender will pick up a true reading anymore think about it the water (coolant) in the tee is now stagnant so will depend on just transfer of heat in the coolant trapped in it.That is if you bleed the air out that will get trapped in the tee to start with being in the up position .The best way to add a temp gauge is to remove the temp light sender on the driver front corner witch with a gauge will not be needed and serves no other purpose and install the pickup directly into head as with any pickup so the sender is in the coolant path and not raised in a dead zone for flow to get a true reading .

 

[blazerboy]

These trucks do need extra warning devices.Thanks rnd-motorsports for the info.

 

[isaacucv]

Well after driving the truck for a few days, I have observed coolant temps to be between 160 and 180. Closer to 180 when moving slowly offroad for an extended period of time. I have oil pressure readings of 50psi at start when cold. Once its warmed up it idles just shy of 30psi and at a high throttle setting, 75psi. It all seems pretty good to me, what do you folks think?

 

[cmroles]

This is great info! I was thinking about using the "Auto Gage" series water temp gauge from Autometer. Seems to run about $30 and is an almost perfect match to the factory voltmeter.

If its possible to separate from its mounting bracket then I intend to put it into the empty space next to VM for easy visibility.

I'm curious though what the "correct" engine temp is for an M1009? I've been through the TM but haven't located an exact number. I "believe" the thermostat is 185 degrees, but I could be wrong.

Auto Meter

One more thing: Does anyone have the maximum safe engine temp? This gauge I was looking at is marked with a "green zone" from 170-230 degrees. If 230 degrees is a dangerous temperature then I may not want that gauge. I don't like the potential problem of the needle reading in the green while the engine is self-destructing...especially if the truck is being driven by someone who doesn't "know her" like I do.