Hey guys, I just bot a 1990 gx, mint. All stock and all original. This thing is super sweet. I just did a coolant flush and added water wetter to it, we''ll see what happens. BUt I am curious as to just where my temp guage should be? I've had the car 5 days and the temp needle sits at exactly half way mark till I rat on it and race for a few minutes, then it goes up about 1/4 inch, almost 2/3s of the way up the guage. It goes down in a few minutes of normal driving but I'm wondering if this is normal and would it help if I changed the thermostat for a cooler setting?
Help.

 

Also would running synthetic Redline or Royal purple in the tranny cool thing off a bit as well?

 

Do not trust your stock temp gauge...it is not linear and is slow to respond (in fact, mine has never indicated anything over 1/2).

Most aftermarket gauges use a 1/8NPT sensor which will screw into the stocker's location.
I'm currently running both gauges and the stocker sits calmly at 1/2 (i.e., "normal") even when the aftermarket indicates temps of 210° (I was testing a fan trigger at the time).
If your stock gauge was reading higher than 1/2, I shudder to think what the actual temp must have been.

Not sure if the synthetics will "cool things down" but they will probably improve the shift action.
Red Line made my tranny act almost new.

 

As answered in the previous thread, the normal operating position for the S5 temp gauge is half way.

The stock sender location is going to vary depending on model year. Sometimes it's a pipe thread, sometimes it's a straight thread. It is basically random which cars got which thread though older cars have more of a chance of being a pipe thread.

While the 1/8 NPT sender will usually fit, it will ruin the threads on the sender, possibly create a leak, and you can crack the iron if you reef down on it.

 

If you're going racing, please get aftermarket water and oil temp gauges. That stock gauge is set to read right in the middle all the time. If it goes past 1/2, then you have a really hot engine and you can easily kill it doing that. (Yes, I know cuz I did it. Twice.)

I have been fighting overheating in my car for ages now. They do overheat easily.