Question on the quooling system...

[3050rpm]

Does the need to add about 1/2 - 1 cup of coolant over time (I'm talking like a month or two here) mean anything to be concerned about? I was reviewing the items to be done at the Inspection services, and checking the coolant level was one thing mentioned rather routinely, as I thought it should be, but my question stems from my thinking that the cooling system is a closed one, like the brake hydraulics, hence any loss indicates a leak somewhere. I see nothing visible from hoses or connections, and when I last changed the plugs they were dry and of the right color. Any thoughts?

[witeshark]

I'd say there must be a slight leak. My mom's Jetta seems to vent a tiny bit once in a great while (I think) cause I can smell it. But the level stays the same, although maybe a tiny bit was added during the last service...

[Dudesky]

It's not unusual, especially during the summer months. It's a closed system, but pressure still vents through the filler cap, releasing some steam. I wouldn't worry about it. I put in Bar's leaks with each flush and fill- good insurance against minor leaks.