Oldsmobile/Buick Repair: engine coolant, coolant level, engine coolant

Question
Sir:

I have a 2002 Olds Intrigue GL Sedan with  3.5 Liter Twin Cam V6 Engine and a 4 speed Automatic Transmission.  The Low Coolant light comes on occasionally, but coolant level is not low.  Coolant has never been changed.  I have  65,000 miles on the car..  Should I change the coolant?  If so, can you tell me where the coolant drain plug is located.  I have looked for over an hour with the car up on blocks and just cannot find it.  Is there any other way to change the coolant myself if there is no plug. Also, could the sensor be bad.  If so, can you also tell me where this low coolant sensor is located.   Thank you so much.

Answer
Hi
The coolant level sensor is located in the bottom of the surge tank (overflow tank). The entire tank MAY  need to be repalced.
The drain cock is located on the drivers side below the radiator hose.
Should you change coolant.... I guess that would be your call... You could have it checked for protection potential.
Does it still look reddish pink or has it turned muddy brown? Have you lost any due to leak?  These would be questions I'd ask.
I hope this helps.
Good Luck
Pawl