My friend JUST got an SS (go him)

We went driving around tonight and the temp gauge was acting all f'd up
If we sat at a light it would goto 210*, or maybe just above it.
When we drove it it would go to like <180*. Then all of a sudden, the low coolant light came on WTF? So we pulled over and popped the cap off. The level was right up to the top.

Does the car need to be cold to re-fill the coolant? What other problem could this be? A bad sensor?
please help, he is sitting right here with me, thanks.

 

Well the coolant light could just be that low coolant sensor going bad. Ive never seen a temp guage (stock) move around like that. Try swapping the thermostat with a new one.

 

Where is the thermo located?

 

 

look right under your EGR pump (if its a 98-00) and follow the big hose from the radiator to the water pump. its a silver round housing. 2 bolts. on the pass. side of the water pump.

 

I had the exact same thing happen, it's a sensor assembly-replaced under warranty. Unless you're certain the car is actually overheating I wouldn't rush to replace parts arbitrarily. Are your air vents blowing hot and cold or just cold when the heat is on? Is the coolant actually low? Is it visibly leaking or leaving coolant puddles anywhere? Does the upper rad hose feel warm/hot after its been running? You get the idea...