Does the gasket and block sealer they call Blue devil really work on vehicles

Sometimes it works sometimes it doesn’t. All depends on just how bad the leak is. Remember it is only temporary if it does work. I had a GM quad four engine that would eat coolant so I tried it, it worked for almost a year before it let go and had it fixed, turned out the head was cracked in two cylinders and wasn’t a headgasket.

Answer not posting

When applied precisely, it works pretty well, at least for a while, and the head has to come off to get it right. But as long as the head's off, why not replace the head gasket.

Absolutely, it will work but you must follow the directions EXACTLY. Hope that helps! Jim