Could someone please help me identify this part indicated in the red box.

 

My guess is the oil filter access (assuming your talking about the circular black plastic cap)

 

My guess would be the cap of your power steering pump, the square cap in the middle of your engine looks more like the oil filler cap. Might help us if we knew exactly which model you have??

Also look in your owners manual as there should be an engine compartment diagram.

 

engine N52 (2006) 525i.

The reason I ask is this morning I discovered a fair amount of oil (doesn't appear to be engine oil) around the housing and it had splashed onto the air filter canister.

 

I thought it was the Oil filter too.

 

Check out step #10
https://5series.net/forums/topic/497...my-535i-today/

I know this is a N54 but the oil filter should be in the same place on a N51/52/52bxx/53 or M54 motor type.

 

Makes sense, thanks. Don;t understand why I would have an oil leak there, will check it out.

 

See this https://5series.net/information/options/engines/

The engine oil is added from the plastic cylinder top.

That is probable brake- or power steering fluid.

 

Could have been a sloppy job of pulling the used filter cartridge out, or fitting the O-rings on the new oil filter cartridge, or failing to lube the new O-rings with oil before installing, or not clicking the new cartridge fully into the receiver, or mis-threading the cap when re-installing. Plenty of opportunities to make a mess.

 

True, but I am only 600 miles away from next oil change and this just happened yesterday. picked up supplies to day, going to change the oil and check it out further.