I took my wrangler jku in for a clutch repair and got it back with a bad shake on idle. Shop said it had nothing to do with the clutch repair. They without my request ran dye through my radiator and cooling system (not sure if it was even my jeep) and stated I was on my way to a head gasket failure. And that it appeared that stop leak had been used when I have never used stop leak at all since I've owned the jeep. No codes and no check engine light. Tell me if this is likely a loose connection from when they did the clutch repair. I know for a fact the battery was disconnected.