heater core took a dump back in may... so I ran a bypass - who needs heat in a chicago summer? So now its November, and i need the heat. I've been quoted $540.00 installed, which is fine, but a buddy asked me if I had tried Bars Leaks on the core... I didn't even know they made something for that... Is it worth a try?

Stop leak is only a band aid that has a lot of other side affects.

Better to replace heater core.
If you are a die hard DIY you could save over 400$ doing it your self.
Good Luck
MT

These heater cores clog too easy. I wouldn't add a stop leak to it. That price is about half of what the dealer will charge. (I did one today)