Oil (maybe) coming through HVAC

[hyperaudible]

I've been noticing a buildup of some sort of greasy sheen on the inside of my windshield, seems to be most concentrated around the air vents at the bottom so I assume it's coming in through the ventilation system.
I can't see anything too suspect with a visual inspection under the hood...

Anyone experienced anything similar before?

[jlevie]

A leaking heater core is a possibilty

[hyperaudible]

That makes sense, I'll have a look. Cheers!

Any other suggestions?

[Varinn]

Not much else to consider, leaky heater core or evaporator maybe. Most likely heater core.

[roguetoaster]

Not getting any pooling/goop in the left hand front foot well? If you really want to rule out the heater core just loop the lines just before the aluminum fittings on the firewall/heater core.

[hyperaudible]

No pools in the foot well, don't seem to be losing any coolant either. I was thinking I'll clean it well and leave the ventilation on full cold and recycle for a while and see if it stops accumulating on the glass. That should isolate the heater core yeah?