Best place to put Temp probe

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RGAZ

RGAZ

Diehard
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73 Duster Slant 6 stock. I do not trust my dash temp gauge, so where is the best place to put an aftermarket mech temp probe? A search kept say in thermostat housing but I did not see a tap spot. Best suggestion wins!

Thanks,
RGAZ
 
Same place the factory did. Right next to the thermostat.
 
But what if I want to keep my existing temp gauge for troubleshooting purposes?
 
If you don't trust your dash temp gauge where's the trust value for troubleshooting?
 
My dash guage works, but has not gradiants on it. I've thought about ploting it out but never got aroud to it. My aftermarket guage sensor in the factory spot in the block near the themostat housing. I ended up wiring up the dash one in a taped port on the radiator (Not particually accurate, but does give feedback as to whats going on). I think an emissions switch went here. What year head do you have? I think the later ones also had a taped port for an emissions vacuum switch near the thermostat housing. There's a NPT plug in the water jacket I think near cylc 5 & 6, but I reall reading that using a sensor there reads kinda low. I've also seen an "extension housing" that would allow you to put another sensor at the thermostat housing.
 
SIX225 said:
My dash guage works, but has not gradiants on it. I've thought about ploting it out but never got aroud to it. My aftermarket guage sensor in the factory spot in the block near the themostat housing. I ended up wiring up the dash one in a taped port on the radiator (Not particually accurate, but does give feedback as to whats going on). I think an emissions switch went here. What year head do you have? I think the later ones also had a taped port for an emissions vacuum switch near the thermostat housing. There's a NPT plug in the water jacket I think near cylc 5 & 6, but I reall reading that using a sensor there reads kinda low. I've also seen an "extension housing" that would allow you to put another sensor at the thermostat housing.
Click to expand...
Not on all of them. The 225 I have in Vixen only has the port next to the thermostat. As you say, the one in the block (if it's there) isn't a good place to measure temperature from as you want that nearest the thermostat as you can get it.
 
A56 said:
If you don't trust your dash temp gauge where's the trust value for troubleshooting?
Click to expand...
I guess I meant more for calibration purposes. To compare the two readings and correlate what the dash gauge says and decide if its "close enough" or should be repaired/replaced. I like the look of stock if I can keep it and I can correlate it. So an option allowing both probes is best.

I went the IR gun way, but wanted to check it through drive cycle on very hot days without jumping out to shoot it. Just a comparison of the gauge if possible while I drive.

So it sounds like I need to use the stock port or possibly find an extended t-stat cover to use both. That is helpful.

RGAZ
 
I used one of these thermostat housings and drilled and tapped the flat area for an aftermarket temperature sensor in combination with the factory setup to “calibrate” my ‘69 Dart temp gauge which has no temperature numbers.

It’s Dorman part number 902-3012.

Not sure if it will fit a slant 6.

It does fit small and big block engines.

E689DFE7-BBE1-4BE3-9F49-CE60C37BF580.jpeg
 
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Assuming you don't have a shutoff valve in your heater hoses. You could make or maybe buy a "T" fitting that you could put into the supply side to the heater core.
 
scatpackbee said:
I used one of these thermostat housings and drilled and tapped the flat area for an aftermarket temperature sensor in combination with the factory setup to “calibrate” my ‘69 Dart temp gauge which has no temperature numbers.

It’s Dorman part number 902-3012.

Not sure if it will fit a slant 6.

It does fit small and big block engines.

View attachment 1716092988
Click to expand...
While this seems like a good option your reading the coolant on the wrong side of the thermostat.... But without a lot of options it still may be your best choice...
 
Google "water neck extension" That's what I am using on my V8. I would assume that the same principle applies to your slant.
 
This is what I was referring to

Amazon has many sizes and a few different types.

If you could get it into you bypass hose that would work well too

Screenshot_20230522-111814.png


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Screenshot_20230522-112149.png
 
Even if not "exact" if you put it in the block drain, (if you can reach it with your mechanical gauge lead that is) it will be a steady deal, you will know where you "normally" read and if it deviates from what your established "normal" is theres still something wrong somewhere in the system....

I put one in my Durango and I don't know if it's how I mounted it or if the gauge is a little out of whack, but with new 195 thermostat (changed a couple of times since aftermarket gauge out in) and everything full I normally read 180, have never seen the 195-200 id expect out of a 360 mag. Occasionally 190 towing and 95* out.... .
I had to screw a pipe extension into where the heater hose returns to the beer barrel intake to get clearance around the beer barrel itself, it's about 4" above the manifold surface and in one side of a "tee". The heater hose that belongs at that port in the other leg of the "tee". The dash gauge still reads off it's stock sensor in it's stock location and the same as always when all is well. Again no numbers on factory gauge. Just a few needle widths short of "straight up".
 
The gauge set I have in there is the better quality auto meter Brand ones not their cheaper "auto gage" line. I have oil pressure water temp and trans temp.
 
Why not just get a brass "T" that has a 1/8 pipe thread male to screw into where the current sensor is ( assuming the sensor is the same thread as a v8) I think it is and then the other two off the tee female threads and put both your sensors in the same spot? It is done all the time with oil pressure sensors and works just fine. You can get the t,s at and automotive or hardware store, fairly common.
 
I've done exactly that before, in my particular case with the Durango I couldn't. There's literally a wall right behind the port for the factory temp sender (front of "beer barrel") on that engine.
On the /6 in my truck there is what I think is a factory pipe plug a few inches away from the factory sending unit hole that could be used for an aftermarket gauge (which is how I'm gonna plumb that one in)
 
Dana67Dart said:
Assuming you don't have a shutoff valve in your heater hoses. You could make or maybe buy a "T" fitting that you could put into the supply side to the heater core.
Click to expand...

Car has factory AC so it has the dual hose valve which I expect is what you mean by shutoff valve.

I am not sure the T will work since the probe portion that goes in the block looked pretty big. I might look into this option though. Thanks.
 
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