Timing failure and oil in intake

Skoda Fabia Jan 2010 1.2 TSI SOHC 8v Direct Injection

Car came to us on the back of a recovery truck with a suspected fuel issue. Customer had said the battery light had been coming on randomly the past few days then the other morning wouldn't start. The oil indicator on the dash started beeping so they checked the level and put approximately 1.5 ltrs in. It was serviced by us in november and does around 20k a year, it's currently 64k at just over three years old. This car has always used oil but apparently this is normal for these kind of engines.

On cranking it was obvious there was little to no compression. There was also no spark and the oil level was slightly overfilled. Code read showed this,



All codes cleared and car started sparking but soon stopped as the cam position sensor code retuned.

Compression test showed zero compression in all 4 cylinders so it was decided that the head required removed. When removing the intake manifold it started pouring out oil, and I mean pouring,




No obvious signs of how all that got in there. Continued to strip the engine and found that (not to much of a surprise) the timing was out. The chain, tensioner etc. we're all still visually ok no apparent sign of any failure, still tensioned ok. Head came off and was met with this,




All four inlet valves bent. Another thing I noticed was that cylinder two had a lot more carbon on it compared to the rest,



This was also apparent on the no. 2 inlet valve.

I can sort the timing out and fix the bent valves out not a problem but what I'm struggling to understand is why the timing jumped in the first place? Also why no. 2 has so much more carbon than the rest and how all that oil got in the intake?

My best guess is that the tensioner failed due to the lack of oil. It is a simple plunger with a spring inside but is oil filled so I'm assuming the lack of oil caused a lack of pressure and caused the tensioner to slack off but that still doesn't explain all that oil in the intake.

Sorry for the long post but I wanted to get all as much info in as possible. Any help/advice from you guys is as always much appreciated. I know some of you have been playing with engines since I was in nappies!