Taking care of some odds and ends while my cylinder head is at the machine shop, and I've discovered a plug hanging down by the front of my motor that doesn't appear to have been connected to anything for quite a while:



Here is a wider shot with the connector circled in red:



Would anyone be kind enough to point me in the direction of what it may be? It's very dirty so I assume it's been unplugged for quite a while, and I'd like to get it cleaned up and back in its home.

 

not for the knock sensor is it?

 

Nope, both knock sensors connected.

 

In the process of removing engines, on multiple occasions I've come across several connectors in various places that aren't connected to anything. I can only assume they're either diagnostic ports, or plugs for various other engines. I think Volvo uses a wiring harness that's ready for anything, rather then use a different harness for whatever configuration is in each car.

If it's running good, and there's no lights on the dash, roll with it

 

On mine it is for the knock sensor. There are two different type of knock sensors you can get. One like the setup you have, where the sensors have the plugs on them individually, and mine has one plug that branches off to two knock sensors and it all one unit.

 

what color are the wires?
I have the same engine and needed to rebuild my engine harness after it burned this summer and there were no "extra" connectors in that area which were left not connected...

EDIT: If your car is from 93 or 94 it could be the connector for the oil level sensor. It's the only thing that is located in that area...however Volvo decided from 94 to leave the sensor away presumably because it was unreliable... Wire colors should be Brown-White and Black.

 

Scutyde, one wire is black, and the other is white/red. I suppose, though, that it could be brown and not red. Thanks!