I just noticed that my coolant is about 1/2 inch below the min mark.

Can I just top it off with something from the auto-parts store, or do I need to use a specific Porsche brand? If I can add something from the auto-parts store, what would I need to get?

Also, is it a big deal if I wait about 300 miles of highway driving before topping it off (just because it will be more convenient for me), or is this something I urgently need to take care off right now? Outside temps will be in the 60s to 70s, where I am.

(I don't think I have a leak, and I don't see any white residue around the filler cap of my 997.1).

 

Almost 8.5 gallons of coolant capacity so I wouldn't be overly concerned about a few ounces especially if you have ruled out a leak. I believe the VW and Audi coolant is same spec as Porsche and maybe a little less expensive. Not sure of the auto parts store specs. Dilute your coolant 50/50 with distilled water and then top off.

 

The system can lose coolant over time. You can just add distilled water. You can check the coolant with some of those test strips if you're really anxious about protection against freezing.

Before you head out though you really should have the car inspected -- from underneath -- looking for any leak sign. The low level could be the early signs of a water pump going bad.

 

Same recommendation as above --- add distilled water.

FYI, adding water was also the recommendation from the dealer.

 

Make sure you are checking the level when cold.

Top off with 50/50 Porsche OEM coolant + Evian bottled water

 

The level goes down as the coolant cools from hot, so if the system was filled to the top mark when the system was warm/hot, then as it cools it will drop normally in level. If it is above the min mark I'd not sweat it. When the system is worked on in any way, you always have air that needs to work its way out as well, which results in a level drop.

I'd top off with distilled water to some place in the middle between min-max, then watch it for a few days driving, and if its not moving don't sweat it.


Remember, as with all fluids, the MAX mark is NOT THE TARGET to fill to.