anti-freeze level

Thought I'd tell any interested readers that the anti-freeze level on my 05 LS V6 always showed full to the proper full line but wasn't full, if I stopped at a light or going through a drive-thru the heat would go cold and the other day no heat period even when driving but when I checked the level when cold or hot it always showed full, but I then recalled several times in the past year that I could hear gurguling sounds going thru the engine so I tryed to add a 20 oz bottle of bottled water from work (free) and it took the whole bottle without changing the level but then I seen bubbles coming up so I refilled the 20 oz bottle and put it in and a 3rd one and then I had heat. I stop there and went and bought pure gold antifreeze and poured some in the 20 oz bottle so I could keep track of how much and it took 3 bottles before the level actually started to rise a little so I stopped. So the conclusion is a big air pocket in system. My temp gauge never showed overheating, always heated up to half way mark. So if your V6 starts blowing cooler or cold when idling then you probably need to add antifreeze.

Thanks for the tip.

Is the line on your recovery tank possibly a stain from a previous coolant level?

-Rod

No, I had the cap off looking down into it.