Might have put this in the wrong place to start with.
I know there have been posts before about this but I'm wondering if anyone has any new information. I've just bought a used 1.7 eco which wasn't making any noise on test drive. The warbling/turkey/bottle filling noise started soon after purchase. Previous posts on here say it's air in fuel system and there appears to be no fix. Took it back to garage. They hadn't heard anything like it before but phoned a local Vauxhall dealer. They were told it's a 'known problem' for which there is no fix. Does anyone know if Vauxhall have given up on finding a solution? I can't believe it's just like it or lump it.