My A4 B8 2.0 TDI had a (slow) oil leak but this morning it has suddenly got much worse. Oil is spraying from the oil filter cap (no leaks when the engine is off), so must be a pressure issue. Does anyone have any experience of this type of issue and what resolved it? I'm thinking of trying to change the oil filter cap but I can't see any visible defects with it. Could it suggest an oil pressure issue/valve. My engine is CJCA apparently.