I am looking to buy this gold 1986 325e. It is very nice, clean, everything works. But there is a loud ticking noise coming from the upper engine. It's not a knock or anything but it's a loud tick. Doesn't seem to hamper performance at all but it doesn't sound the greatest. Anyone have any idea what it could be? Oh and i'm curious, what does the "e" stand for behind the 325? I know 325i means injected. What about e?