Why do the rockers on your opel corsa 130i make a noise the oil is enough and the rockers can not be set?

If the rockers on your Opel Corsa 130i are making noise despite having sufficient oil and being unable to be adjusted, it could indicate wear or damage to the rocker arms, lifters, or camshaft. Insufficient oil pressure or poor oil quality can also lead to inadequate lubrication, causing noise. Additionally, it might be worthwhile to check for any issues with the valve clearance or the timing mechanism. Consulting a mechanic for a thorough inspection would be advisable.