I just changed the thermostat on my 1985 caprice with an lg4 engine. Although it is not a thirdgen, it shares the same engine as the trans am. I get the most support from this site and i am a regular member here so please please please bare with me.

Car was overheating on the way home from work so i towed it home.

Pulled out the thermostat the next day and played with it with a screwdriver, it was stuck closed.

Ran to autozone, grabbed a 160 degree thermostat, popped it in. Everything went perfect.

Drove it around for quite awhile but the gauge refuses to move. It stays a little above cold.

When i first turn the car on it will immediately rise about a centimeter and stay there the entire time, when i turn the car off it drops back down a centimeter.

I drove it 15 miles this morning and the gauge didnt budge, popped the hood and it didnt seem to be overheating.

Should i have gotten a 180 degree thermostat? Did i break my coolant sensor or something?

I also broke one of the nipples on the TVS vacuum valve that screws into the thermostat housing. I cant seem to find a replacement at autozone. Anyone know where i can get one of these?

 

Been reading up, tstat is supposed to be 195 degrees, my 160 is opening too early causing my car to cool more effectively. A few people posted their gauge doesnt move too far passed 110 with a 160 degree tstat.

The plug i was checking was for the cts since i believed that controlled the gauge, i am going to check the actual sender to make sure its plugged in, get a 180 tstat and see if i can get this thing running on operating temps.

Im probably going to hit the junkyard for that broken tvs valve. Cant find it anywhere

 

My temp gauge sender has a really strange way of connecting to the wire.
Nothing but a female connecter that slides sideways on the little tip of it.
Its out in the open just waiting to come off.

 

Yep, same kind of sliding connector here. Had to wiggle it about once to get my gauge readings back.
If you can find that sensor, try moving the connector around.

 

I also have that sliding connector on my 84.