Best location for water temp probe

[Sawbladz]

So I am looking to install my temp probe for an Autometer coolant temp gauge. The probe came with an adapter fitting that fits the empty spot on my water neck. However, that same spot has the same thread as the extra hole in the bottom on my Koyo rad. So my question is, where is the better place to install the probe?

 

[jetjock]

It really ought to be on the engine side of the thermostat...

 

[VooDoo]

It will give the temp closest to the engine were the temp will be more accurate. The radiator temp will fluctuate more I would think.

 

[92TealSupra]

It really ought to be on the engine side of the thermostat...

Very true. I see a lot of people put them on the top rad hose. That temp doesn't really do much until the thermostat has opened, I would have the thermostat tapped at the bottom before the thermostat.

 

[Sawbladz]

Ok, how about the location for the cold start injector probe? The 24mm one on top of the water neck. This would put it on the engine side of the housing. I could likely find an adapter fitting for the temp probe to fit it in this location. My only concern is that the probe isn't that long. would this cause issues with the gauge reading correctly?

 

[--Golli]

I've got a temp sender in the Cold Start Injector Switch. It's a 16mm by 1.5 pitch.

 

[Sawbladz]

Time to add pictures. I work better with visuals.

This is my current thermostat housing. The sensor has the 16x1.5 adapter on it and threads in nicely.

All the fittings I have. Haven't checked the thread size/pitch on the the other fitting but it's too large for any existing location.The cold start injector probe location is smaller than the 16x1.5 but not by much. Would need to check the size of the probe to find the appropriate fitting.

This is the difference in length of the sensors. Worried the new sensor won't be in the coolant and therefore won't get an accurate reading. Not sure if the area behind the thermostat is completely filled with coolant.

 

[--Golli]

Put it this way. I ordered this part In 16mm x 1.5 and it went straight into the cold start injector time switch.

Don't know wh it won't work for you, but its working perfectly for me.

As for an accurate reading. The Thermostat will be open before you need to know exactly and accurately what the water temp is doing. Once it is open it will give you an accurate reading.

 

[Fubar231]

Comp glitched, double posted.

 

[Fubar231]

As for an accurate reading. The Thermostat will be open before you need to know exactly and accurately what the water temp is doing. Once it is open it will give you an accurate reading.

The exact reason i wouldnt put it on that side of the thermostat.

Thermostat fails and doesn't open, your temp gauge isn't going to know untill its too late.

I used the tapped area that the sensor for the gauge-cluster water temp gauge, since i replaced it with a aftermarket no need for it to be there. (Not the ECU one, the Gauge-Cluster one)

 

[kotu100]

You could drill out the bottom of the adapter for the sensor, it could help with the flow around the sensor. The way it looks now it seems like the reading wouldn't be too accurate cuz the same coolant would be floating around in that little crevice... Know wat I mean?

 

[grimreaper]

see that flat spot right above the ecu temp sender? drill and tap that for what ever threads your aftermarket sender is for. Everything else stays hooked up as it should be and you get accurate temp readings.

Mine was 1/8npt. IIRC the tap cost >$5 at homedepot.

 

[--Golli]

The exact reason i wouldnt put it on that side of the thermostat.
Thermostat fails and doesn't open, your temp gauge isn't going to know untill its too late.
I used the tapped area that the sensor for the gauge-cluster water temp gauge, since i replaced it with a aftermarket no need for it to be there. (Not the ECU one, the Gauge-Cluster one)

Don't quite understand your theory. But if the thermostat doesn't open with the temp senser after the thermostate, it isnt going to get any where near the real temperature of water in the block.
At least putting it in the cold inector port your gonna know the rough water temp before it opens. I'm thinking around 2-3 degrees difference here. It's still got movement about it from the turbo coolant feed going to the turbo.

Or you could just do what Grim has said, probs the best thing to do IMO.

 

[Sawbladz]

see that flat spot right above the ecu temp sender? drill and tap that for what ever threads your aftermarket sender is for. Everything else stays hooked up as it should be and you get accurate temp readings.

Mine was 1/8npt. IIRC the tap cost >$5 at homedepot.

I think that's what I will do. I already have the tap and it will allow the sensor to be as far into the stream as possible. I guess I will remove the hose/neck and thermostat so that I can catch all the filings somehow. Thanks for the idea.