Mechanical/Electrical Water Temp Install

[OMFGeofffff]

So I'm getting a couple gauges in on a trade. Both are mechanical autometer(boost, water temp). The question is has anyone installed one of the mechanical water temp gauges in your car? Where did you tap or screw the probe into? I'm not sure what the size is but it does say it has a 1/2"NPT adapter. Any ideas?

 

The first question would be, do you still have your emissions stuff intact? The reason being is that the easiest place to install the probe is where the thermo-vacuum switch is on the t-stat housing. Autometer makes metric adapters for those probes, or you can tap that hole to a 3/8" npt if that adapter is included. Otherwise I'd say your choices are somewhat limited. The t-stat housing is fairly cramped up in all stock form, not a lot of extra room if you are still feeding coolant to the turbo and the sandwich oil cooler and the throttle body. I'd say the margin of error is too great to try and tap the head directly, same with the block. Which leaves us with the water pump or the water pipe, neither of which are very accessible. You could cobble up a brass tee with hose fittings on opposite sides and the probe running perpendicular to the hose and put it in line with the heater hose coming from the t-stat housing I guess.

 

[OMFGeofffff]

Turns out the kid didn't know what he had. It's a short sweep electric. So now I just to to find a spot for 1/8"NPT. I'll probably end up using a upper radiator hose tee.

 

That would work, if you only want to read accurate temp while the thermostat is open.

 

[alansupra94]

So would you where would you run that probe? I was thinking about it but can't seem to wrap my head around it. Couldn't he install it in the same area as the emission crap and be set? Isn't the stock temperature probe there too?

Confused.

 

Quoting galant1517:
The first question would be, do you still have your emissions stuff intact? The reason being is that the easiest place to install the probe is where the thermo-vacuum switch is on the t-stat housing. Autometer makes metric adapters for those probes, or you can tap that hole to a 3/8" npt if that adapter is included. Otherwise I'd say your choices are somewhat limited. The t-stat housing is fairly cramped up in all stock form, not a lot of extra room if you are still feeding coolant to the turbo and the sandwich oil cooler and the throttle body. I'd say the margin of error is too great to try and tap the head directly, same with the block. Which leaves us with the water pump or the water pipe, neither of which are very accessible. You could cobble up a brass tee with hose fittings on opposite sides and the probe running perpendicular to the hose and put it in line with the heater hose coming from the t-stat housing I guess.



This hose constantly receives engine temperature coolant at all times. The upper radiator hose tee would read low until the t-stat opened, and probably would fluctuate 10-20 degrees while warm due to normal t-stat operation.

 

[Specter]

Would not a lower radiator hose tee show much more accurate temperature? I am planning to install a tee with fittings in there for water temperature too.

 

The most ideal location is directly into the lower portion of the thermostat housing. It constantly has coolant flow as long as the engine is running, plus the direction of coolant flow through the block and head places this location immediately after the hottest part of the engine. The lower hose receives coolant after it has gone through the radiator, making the readings there colder than actual engine temp. Most people want the stock gauge functioning also, other wise you'd just pull the stock sender and replace it. In my setup I have all the room in the world because I have an air cooled oil cooler and my turbo isn't water fed. But all stock vehicles have all of that crap coming off of the lower housing, making it difficult to add anything. The heater hose is the next best location because it has the greatest volume of flow leaving that housing on a consistent basis, and is only a few inches downstream, making it the next hottest location.

 

[OMFGeofffff]

I think I'll just get a 1g thermostat housing. I read it has a unused port that the sender will fit perfectly in to. Does anyone know if vr4 housings has this too? On the 1g it is on the rear left of the housing and has a plug in it.

 

[JSchleim18]

IIRC, for the Galant t-stat housing, there is a single pin sensor (Blue/Black wire) that is in that hole that the DSM t-stat housing has plugged. I don't know the thread pitch on the Galant housing for that sensor but the thread pitch on the DSM housing is BSPT, not NPT. This is OK though. I just put teflon paste on the threads and tightened away. No leaks so far. This is where I installed my water temp sensor.

 

[OMFGeofffff]

^^ After looking around it looks like that sensor is for the emergency fan switch. It turns both fans on high. It's useless to me since I have no a/c and a 14" slim fan. That's where I'm going to put it.

 

Perfect.

 

[OMFGeofffff]

Now that summer hit I am really thinking about putting my a/c back in. So now I want to retain all my sensors on my thermostat housing. That means my plans are changing on the location of where I'm putting the sender. Here's a list of option I've came up with. Most expensive to least expensive. I'd really like to avoid taking off the entire t-stat housing.

A) Use one of those radiator hose adapters and putting it in one of the heater hoses. 5/8" correct? Also does it matter which hose?
B) Use a 1/8" to 3/8" NPT adapter and either tapping the thermovalve location to accommodate 3/8" NPT or just threading it in with good sealer and hope for the best.
C) Remove emergency fan switch(good or bad idea?) and either tap it 1/8" NPT or just threading it in with good sealer and hope for the best.


Let me know what you guys think.