I had a similar problem with my 2001 SL2, which also has 145k miles.
My coolant reservoir cap seal had failed because I'd over tightened it after replacing the coolant. I replaced the cap and the coolant stopped boiling over, because the new cap was able to keep the system pressurized.
You can get a new generic GM coolant cap at Autozone for about $10 bucks.
As for bleeding the air from the coolant system, your car automaticly bleeds the air. There is a narrow hose that runs from the upper area of the back of the engine head on the driver's side, then hugs the firewall, and routes to the top of the coolant reservoir.
As for the fan not kicking in. I don't remember if mine did when my coolant boiled. I know that my fan DOES kick in when the dash temp gauge goes above 5/8 on the scale.
Sunday, September 7th, 2008 AT 8:34 PM