I just replace my thermostat last night as it was a 160 unit like I suspected. I put in a nice new 195 t-stat and I'm wondering if there is some kind of post about how to read the factory sweep temp guages?

Starts at 100 with 10 hash marks up to 220...then 10 more hash marks to 260....WTF?!?! The car was running just below the 5th mark between 100 and 220 which i figured to be around 160-170 and last night it's now towards the 3/4 mark between 100 and 220.

Now it just seems overkill to go get myself another temp guage, but is there any science to this or is it just one mad guessing game?

- the car is an 89 GTA if you didn't notice my name and it's a sweep guage that probably sweeps 140 degrees...give or take a few dozen degrees.

 

It's a guess. The stock guages are usually not that accurate, just give you an idea as to what is going on.

 

With a 195 stat the factory guage is designed to run on the first line between the 100/220 mark. Most GM cars will run on a fixed point usually a line, and although it may not be perfectly linear it gives the operator a reference point. When it deviates from that reference it is usually a sign of an impending problem.

 

The factory guage temp sensor is in the drivers side head. Depending on where you install your new guage, the readings will be different. The factory guage is not even close. I installed an AutoMeter temp guage. the sensor is in the intake manifold. The factory guage reads about 160 (with a 180 stat). The manifold guage reads about 190 most of the time, but it's always going to read hotter. Heat rises.

 

Well the temp has gone up since I put in the 195 but I guess w/o adding an extra temp guage there's really no way of knowing how much.

Sounds like I might be getting myself a guage cluster sometime in the near future, but being that I'm not looking to push this motor too hard it's not really a priority. Just trying to work out whatever bugs I come across to get it running well enough to let me build the rest of the car...then comes the serious motor.

Thanks for the tips guys

 

If you look at the three lines, directly between the first two is about 180 degrees, not 160 like you may think. The numbers get closer together as you go up.