Went to start my car after it sat for about an hour. Temp gauge went to red line. No antifreeze was leaking. First thought was the thermostat. Changed that out. Went to start car it still runs hit to red line. Any other possibles it could be?

1999 3.0 CL with 259k

 

any recent maintenance?

 

None

 

What’s your coolant level at? When you replaced the tstat did you burp the cooling system?

 

Drained it and refilled it

 

Make sure the cooling fans work

 

Both fans work