Coolant and Oil Temp Sensor

[Zeus51]

Yes, coolant temp and oil pressure are the 2 most important items for monitoring an engine. If either of these go out of range (i.e. very low oil pressure or very high coolant temp), damage to your engine will occur. Thinking back, I think the only vehicles I have ever had an oil temp gauge was my VW powered vehicles. Since they are air cooled, there is no coolant so oil temp was needed along with pressure.

Now that we have the oil pressure sensor issue corrected. How hard is it to swap to the humvee crossover? Does it match up exactly? Does the heater core hose still come off the crossover? Can you remove the existing 6.2 crossover without removing the injection pump?

 

[chevymike]

Yes, the crossover fits without removing the pump and fits correctly. The only thing I had to due was to tweak the return fuel line on the driver side, since there is a boss there for a sensor that is not on the original one. The crossover to water pump hose is at a different angle and you will need a reducer adapter and a 45* formed hose to fit correctly. I show all of this on my M1010 build thread on Expedition Portal. It should give you a good idea of what I did with pics.

Desert Turtle - M1010 Build

In following with some other "Turtle" builds like Turtle Expedition and the Mountian Turtle M1010 build, I bring you Desert Turtle, our '84 M1010. Actually this is my second M1010. The first build got started but at that time I decided to go a different route and bought a Dodge Ram and FWC...

www.expeditionportal.com

 

[Zeus51]

Yes, the crossover fits without removing the pump and fits correctly. The only thing I had to due was to tweak the return fuel line on the driver side, since there is a boss there for a sensor that is not on the original one. The crossover to water pump hose is at a different angle and you will need a reducer adapter and a 45* formed hose to fit correctly. I show all of this on my M1010 build thread on Expedition Portal. It should give you a good idea of what I did with pics.

Desert Turtle - M1010 Build

In following with some other "Turtle" builds like Turtle Expedition and the Mountian Turtle M1010 build, I bring you Desert Turtle, our '84 M1010. Actually this is my second M1010. The first build got started but at that time I decided to go a different route and bought a Dodge Ram and FWC...

www.expeditionportal.com

I started trying to pull the crossover pipe and I am trouble getting the bolt closest to the IP bracket on the right side off. Honestly, I can't seem to get a socket and ratchet on it without taking down the bracket and IP. Thoughts?

Also, have you noticed a significant difference since adding the paradox cooling system in your build thread?
Is the HMMWV crossover GM12554091?

 

[cucvrus]

Zeus51. When I was younger I had a friend that had a Jeep CJ7 with a 401 in it. He called it 16 gauge. It had 16 gauges in it. It was very cool looking but a mechanical nightmare. I remember it had gauges for both axles ,transfer case, fuel pressure, pyrometers, tilt gauge, every gauge imaginable. It was a nice Jeep if ever one did exist. It was great and he was always working on it. Short story. It burned from and electrical fire in the charging system. He was driving it down the road it started smoking under the hood and it burnt to the ground. Something I learned in my life. Keep it basic and keep it as stupid simple as possible. The CUCV is about as simple as it comes and kept in stock form it will last for many years. I have added a few tachometers and other gauges to my CUCV's over time. As I look back the stock ones with no radio and bone bare were my favorites and the ones I spent the least time and money on. I agree with the others the basic gauges are about all you need. The oil temperature will stay about the same as the water temperature because they are both being cooled thru the same radiator. And putting wiring under the truck near the drain plug is asking for trouble on an off road vehicle. Or maybe you don't run them like I do. Good Luck and Be safe. Do as you wish make sure you fuse everything close to the fuse box as possible. I seen cars burnt with big amps in the trunk and the fuse was in the trunk next to the amp and being fed from the battery up in the front under the hood.

 

[cucvrus]

I started trying to pull the crossover pipe and I am trouble getting the bolt closest to the IP bracket on the right side off. Honestly, I can't seem to get a socket and ratchet on it without taking down the bracket and IP. Thoughts?

Also, have you noticed a significant difference since adding the paradox cooling system in your build thread?
Is the HMMWV crossover GM12554091?

Start that one first and leave them all as loose as you can. I still have difficulty doing this installation from time to time also. Good Luck.

 

[cucvrus]

I am confused. Why are you wanting to measure your oil temperature when oil pressure is more important? The very first gauges to be considered are oil pressure and water temperature. These are of paramount importance for monitoring normal engine functions. After oil pressure and water temperature, I would say that transmission temperature would be next in line of importance. THEN oil temperature, THEN maybe fuel pressure. Those are the 5 gauges, in order of importance, that should be considered to be installed. That is exactly what I am doing in my M1028 rebuild. I am fabricating a custom gauge cluster housing for mounting those 5 mechanical gauges along with a HMMWV tachometer.
View attachment 794514View attachment 794515View attachment 794516

Well your post helped me out. I have a brand new tachometer like that in my stash. Don't know if I will ever use it but I have it. So I got that going for me. Does a HMMWV have a cable driven speedometer and are the HMMWV gauges all weather resistant?

 

[chevymike]

I started trying to pull the crossover pipe and I am trouble getting the bolt closest to the IP bracket on the right side off. Honestly, I can't seem to get a socket and ratchet on it without taking down the bracket and IP. Thoughts?

Also, have you noticed a significant difference since adding the paradox cooling system in your build thread?
Is the HMMWV crossover GM12554091?

I had to use a combo of ratcheting wrenches, swivel sockets and such. It was a PITA but they all will come out. To get the crossover out and new one back in, you have to do a little weird twisting of the tube to get it to snake out. It all will come out and back in. You will want to loosen up that one fuel return line so it can move away from the new crossover. Then tweak to fit. I made a bracket down at the head to raise that tube up, to help.

I don't recall the part number but I believe there is only one version for the HMMWV engine.

 

[Zeus51]

Zeus51. When I was younger I had a friend that had a Jeep CJ7 with a 401 in it. He called it 16 gauge. It had 16 gauges in it. It was very cool looking but a mechanical nightmare. I remember it had gauges for both axles ,transfer case, fuel pressure, pyrometers, tilt gauge, every gauge imaginable. It was a nice Jeep if ever one did exist. It was great and he was always working on it. Short story. It burned from and electrical fire in the charging system. He was driving it down the road it started smoking under the hood and it burnt to the ground. Something I learned in my life. Keep it basic and keep it as stupid simple as possible. The CUCV is about as simple as it comes and kept in stock form it will last for many years. I have added a few tachometers and other gauges to my CUCV's over time. As I look back the stock ones with no radio and bone bare were my favorites and the ones I spent the least time and money on. I agree with the others the basic gauges are about all you need. The oil temperature will stay about the same as the water temperature because they are both being cooled thru the same radiator. And putting wiring under the truck near the drain plug is asking for trouble on an off road vehicle. Or maybe you don't run them like I do. Good Luck and Be safe. Do as you wish make sure you fuse everything close to the fuse box as possible. I seen cars burnt with big amps in the trunk and the fuse was in the trunk next to the amp and being fed from the battery up in the front under the hood.

Hahaha! I definitely don't need a truck that I have to name 16 gauge. I was however wanting enough gauges to monitor: coolant, oil, maybe vac pressure (haven't decided yet). I just got carried away with the oil temp and wasn't thinking about pressure. Since the beginning of this thread, I have been able to replace the radiator and was hoping to place a few sensors while I had the coolant out.

 

[Zeus51]

I had to use a combo of ratcheting wrenches, swivel sockets and such. It was a PITA but they all will come out. To get the crossover out and new one back in, you have to do a little weird twisting of the tube to get it to snake out. It all will come out and back in. You will want to loosen up that one fuel return line so it can move away from the new crossover. Then tweak to fit. I made a bracket down at the head to raise that tube up, to help.

I don't recall the part number but I believe there is only one version for the HMMWV engine.

When you installed the Paradox coolant system, did you have to get rid of the rear drivers GP controller sensor? It looks like the lines insert at that location.

 

[chevymike]

When you installed the Paradox coolant system, did you have to get rid of the rear drivers GP controller sensor? It looks like the lines insert at that location.

That's exactly why I put in the new crossover tube. I moved rear sensor up to the driver side crossover and put the new temp sensor into the pass side.

 

[Zeus51]

That's exactly why I put in the new crossover tube. I moved rear sensor up to the driver side crossover and put the new temp sensor into the pass side.

Thanks that makes sense. I’m waiting for my profile to be approved by the expedition portal so I can see your pics. Thanks!

 

[chevymike]

Thanks that makes sense. I’m waiting for my profile to be approved by the expedition portal so I can see your pics. Thanks!

When signing up, I don't think anyone approves it. You should get an email to authenticate your account.

 

[Zeus51]

When signing up, I don't think anyone approves it. You should get an email to authenticate your account.

Thanks! You don't need approval to view the thread, however you need approval to see the pictures in full size. Otherwise, they end up being 1" squares on your screen that you can't enlarge. Interesting build you have there. I am interested in seeing the final outcome. I especially like your make shift harmonic balancer tool. It looked like it installed the seal much easier than my wood block and hammer technique. I've loved my Fluidampr. I'm sure you will too. I have decided to order and install the Hmmwv crossover (since the top bolt on the water outlet broke in half while trying to get it out). After I saw what was left of the bolt, it was clear that it was the wrong thread to begin with and someone just rammed it in threads.

So is the oil temp dummy light sensor the one that exits just behind the glow plug control sensor? Does it have the single orange wire with the 90degree fitting (see pic). I need to know so I can install the tee while I have stuff pulled apart.

 

[Sharecropper]

Yep that’s the oil pressure idiot light sensor. Tee off that to install an additional gauge sensor.

 

[Zeus51]

Yep that’s the oil pressure idiot light sensor. Tee off that to install an additional gauge sensor.

Thanks Sharecropper, i looked thru the TM's and didn't see it listed in the parts manual. is there a better manual?


Edit: I found the correct manual that shows this sensor. Sorry to bother with a dumb question

 

[Zeus51]

i'm sorry for the beginner level questions. but i don't seem to have a socket that will fit the oil pressure sensor. what size is it?

 

[cucvrus]

Special oil pressure sending unit socket. You can get it off with a similar sized deep socket. But yes they make a socket to fit the sending units. I have a Snap-On one. you can buy a HF one real cheap. I have mine 35 years and used it less then a dozen times. Good Luck. Be Safe.

 

[Sharecropper]

i'm sorry for the beginner level questions. but i don't seem to have a socket that will fit the oil pressure sensor. what size is it?

It is called an All-Sixteenths. A plumbers wrench.

 

[Zeus51]

Special oil pressure sending unit socket. You can get it off with a similar sized deep socket. But yes they make a socket to fit the sending units. I have a Snap-On one. you can buy a HF one real cheap. I have mine 35 years and used it less then a dozen times. Good Luck. Be Safe.
[/QUOT
Fantastic.... this rabbit hole is getting expensive..... haha!

 

[Zeus51]

Yes, the crossover fits without removing the pump and fits correctly. The only thing I had to due was to tweak the return fuel line on the driver side, since there is a boss there for a sensor that is not on the original one. The crossover to water pump hose is at a different angle and you will need a reducer adapter and a 45* formed hose to fit correctly. I show all of this on my M1010 build thread on Expedition Portal. It should give you a good idea of what I did with pics.

Desert Turtle - M1010 Build

In following with some other "Turtle" builds like Turtle Expedition and the Mountian Turtle M1010 build, I bring you Desert Turtle, our '84 M1010. Actually this is my second M1010. The first build got started but at that time I decided to go a different route and bought a Dodge Ram and FWC...

www.expeditionportal.com

I just received the hmmwv crossover today. I thought the threaded port going to the water pump was going to be 1/2”NPT. But it seems bigger. Do you happen to know what it is?

Also aren’t the other ports on the top of the crossover 1/2” NPT?