Can anyone tell me what the coolant capacity is for a 3.1L V6 is? I don't have an owners manual, I can't find it in Haynes repair manual and I can't find it here on the wonderful internet. I need to flush and change the anti-freeze in my '92 Lumina and need to know. Any tips or advice on doing it would be helpful also. I'm having a heating problem and I put in a new thermostat which didn't solve the problem but did discover that the anti-freeze looks BAD. Thick and brown. From what I've read here in this forum it's looking like the problem is pointing to the heater core being the culprit. Does it make sense to try the flush and change first to see what happens? I'm new here. Thanks for any help or advice.