Temp Gauge Issue

[alburms311]

I installed a Sunpro Mechanical Temp gauge this weekend, AA Part No. CP8217. I used the open plug on the water pump to install the sensor using the supplied adapters, and temporarily mounted the gauge under the toggle switches inside. The gauge reads 160-165 while driving around, will dip to 120 then back up(I assume this is the tstat opening) then when I park and shut down, the gauge will slowly climb to 190-195. Shouldn't the gauge read 190-195 or a bit higher while driving?I attempted to remove any air from the system that may have gotten trapped when I installed it, which there was some, and refilled to proper level. Any thoughts?

 

[joliver]

I can tell you my setup is exactly the same using the plug in the water pump for the sender and I typically see the thermostat open around 175ish then dip back down and run at 160. I am planning on trying a new 190 or 195 degree thermostat to see if that helps my working temp run up closer to 190. I am however curious if the water pump is a good spot for the temp sender.

 

[Warthog]

without physically inspecting the t-stat, how do you know it is a 195degree unit? It might be a 165.

 

[cpf240]

My guess would be heat soak. When the engine is running, the coolant is circulating, fan is blowing, thus regulating the temps. Once the engine is shutdown, there is no, or little, flow of coolant, so temps over various parts of the engine will equalize a bit before they really start to cool.

 

[alburms311]

cpf240, Some of my research seemed to point to heat soak, I just thought the gauge should read higher while driving. Warthog, I replaced my tstat a month or so back, used AA Part No. 14429, 190 degree.

 

[m1009Aaron]

I was thinking of installing a temperature gauge so I can properly adjust some electric fans I plan to install in the future. Question: Is the normal operating temperature around 160 - 165 degrees? Why would you want the engine to be closer to 190 degrees? Any help would be greatly appreciated!

 

[TGP (IL)]

Nice Install.
However I believe the water pump is not the ideal place for the sender/bulb. Your reading cooled water. For a more accurate reading it should be placed in the head, water manifold, or somewhere in the intake coolant passage,Engine side of the Thermostat for true engine temperature.
Tom

 

[cliffyp]

I was thinking of installing a temperature gauge so I can properly adjust some electric fans I plan to install in the future. Question: Is the normal operating temperature around 160 - 165 degrees? Why would you want the engine to be closer to 190 degrees? Any help would be greatly appreciated!

According to TM-9-2815-237-34 the normal operating range for the 6.2 is 190-230*. The stock thermostat is 190-195. My temp gauge sat dead on 190 while driving, a little under while idling.

 

[cliffyp]

I replaced the idiot light sender with the send for my gauge located at the font on the driver's side.

 

[MTMUDRUNNER]

I replaced the idiot light sender with the send for my gauge located at the font on the driver's side.

I did the same thing, works good.

 

[Rumur]

I used to work for Autometer gauges and can maybe help out with this.
First, the water pump is not the ideal location for the sender, there are a couple of issues with it being there. 1 has already been mentioned in that the coolant at the pump is coolant that has just been cooled by the radiator. #2 is that even with a full coolant load, as the pump spins it creates cavitation which will also mess with the reading. The best place is one of the ones mentioned above. Also if the probe is touching the cast iron on the inside of the hole, that can also mess with your reading.

The next thing is the thermostat itself. Pardon my ignorance as I am new to the MV world, but am I correct in assuming that these vehicles do not have a computer? Do they have O2 sensors? If they do not and you are concerned about the temp your engine is producing, you can run a lower temp stat. If they do, you would need to run a 195 as that is what the system is designed to use. Any lower temp can allow the engine to run rich. To see what temp your thermostat is, you can remove it and turn it over. Stamped into the pill in the center is the degree stamping that will tell you.

 

[TGP (IL)]

Your point are all Valid.
There no ECM or other emission sensors other than cold timing advance and higher idle.
You could run a lower thermostat but if you go to cold you risk cold cylinders and the problems that can cause, Carbon, sludge,raw fuel dilution, Etc.
180 Deg. T-stat is as cold as I would use.
Tom

 

[Rumur]

I keep forgetting we are talking about diesels and how critical temps can be.

Thanks

 

[MarcusOReallyus]

Yeah, those of us that are kinda new to diesels have that problem!


But good info on the temp guage, thanks!