Thoughts on Temp gauge issue?

[cbrown9064]

On the road this morning and the temp gauge is damn near "cold". Checked the other sensor (computer) and coolant temp showed 192 at this moment.

With the blower, the revised crossover tube I have positions the gauge temp sensor underneath the top tube (screws in from the bottom).

I have checked the coolant and every time I crack the bung coolant comes out. So I don't think there is an air bubble, but perhaps? Thoughts?

Here is a pic of the gauge when computer shows 192
https://dl.dropboxusercontent.com/u/49202195/tempgauge103015.jpg

And here is a pic of the engine, so you can see the crossover.
https://dl.dropboxusercontent.com/u/49202195/engine102315.jpg

Cant seem to get the images to show up in post, but the links take you to them on Dropbox.

 

[DSG2003Mach1]

to make sure I have this straight, the gauge on the dash is reading low as pictured but checking the temp through the OBD2 port its showing 192? There would have to be something from the pcm to/including the coolant temp gauge then

 

[cbrown9064]

to make sure I have this straight, the gauge on the dash is reading low as pictured but checking the temp through the OBD2 port its showing 192? There would have to be something from the pcm to/including the coolant temp gauge then

On these cars, there are two sensors. One for the PCM and one for the gauge. I checked the PCM for temp and it was 192, while the analog gauge read basically "cold". Either there is air right above the gauge sender or something is wack with the gauge in the cluster itself. Perhaps?

 

[mwolson]

Find a 200 or 500 ohm pot and set it to 10 ohms (9.7 to be exact). Disconnect the temp gauge sensor wire (Red/White) and put the 10 ohm pot across the harness pins or from the sensor wire to ground depending on which style sensor you have. Turn the key on and it should read right at the hot mark. As you raise the resistance of the pot the temperature should read lower.

 

[cbrown9064]

Find a 200 or 500 ohm pot and set it to 10 ohms (9.7 to be exact). Disconnect the temp gauge sensor wire (Red/White) and put the 10 ohm pot across the harness pins or from the sensor wire to ground depending on which style sensor you have. Turn the key on and it should read right at the hot mark. As you raise the resistance of the pot the temperature should read lower.

Awesome, thanks Mark! My buddy has a pot and will give this a try. I have the one wire sensor (old standard style), so will run to a good ground.

 

[mwolson]

It should be near the cold mark when you set the pot at about 74 ohms too.