I have a 2010 320i Sport Automatic. 60k  miles.  In heavy slow moving traffic I get the low oil pressure warning light. It doesn’t happen on the motorway. The car drives perfectly. I’ve had it in at my trusted independent garage and they changed oil and filter. They found remnants of the chain guide etc but the problem has returned within a few hundred miles of driving. Because the car doesn’t go into Limp mode and drives as intended, my instinct is that it’s not causing any engine damage but it’s definitely spoiling my enjoyment of the car. I wish I could find out why it happens. Any ideas? 

Morning Jack

Welcome to the Forum

Not good news and although you aren't seeing visible signs, low oil pressure will over time start to reduce oil feed to probably the upper parts of the engine. As your garage found evidence of chain guide wear/brake up it needs investigation. I would start with simple stuff Check/change the Oil Pressure switch just in case it is that simple. The next bit involves dropping the sump to check the Oil Pick up pipe (I have seen one with a split "O" ring seal that gave similar symptoms to yours (flickering oi light at tick over) If the sump is off clean it out and I would change the oil pump tensioner and guide.

Hope this is helpful

Dave