meternerd

I have a small leak when driving, but not when idling. I have been using Pentofrost" to keep it full, but changed to Prestone universal that is guaranteed to work with any car and not void the warranty. I go through about a half gallon of 50/50 mix every month. Much cheaper than Pentofrost. Any potential issues? I think I "fixed" the leak with Bars-Leak (the copper stuff), but hope I'm not creating more problems.

clancy

The overflow reservoir is known to develop micro cracks and leak. Also the bottom has a nipple that cracks. Also the T that comes off the top. Otherwise there are many hoses in more difficult locations that develop leaks. Lots has been posted over the years if you are skillful at searching.

Prospeeder

Maybe you should get the leak repaired! Dont put that sort of stuff in the coolant. It could block up the heater core, they are very clog prone.