Hello Forum, I’ll make it short. I bought an Arosa for my son. Test drive was short and funny, car found for Funny, bought for Sonnemann. Now it turns out, in warm condition the thing rumbles in idle. Determined, no combustion in the 4th cylinder. Quite much read from distributor fingers to camshaft. I am the way of the cheapest resistance and have bought new candles, cables, distributor cap and fingers. Everything without change. Then dug a bit deeper, wanted the cup plunger, and found the following “nock” on the 4th cylinder. See picture. My question. is that enough to greatly affect the idleness? I stopped further investigation. For the time being. When the part is completely over, no problem, there are enough sets out there with cups and seals etc. What is your assessment about this ? (Is this the outlet Nocke? ) Is around the Arosa 6H 1999 1.0 liters with say and write 232000 KM on it. Yes, of course the much, abe r, 2 years Tüv and demonstrably before 2000km new head seal, ZR, etc.