Probably the PD unit injectors operated from the cam shaft - If these engines are run on the wrong oil without anti foaming (proper vw spec) then the cam/injectors can badly wear and presumably the cam and followers have been changed but have the unit injectors?

Big ends don't give you top end noise and if gone can be quiet when cold but really bad when hot and the oil is thin

Saying that the BLS engine has been known to throw a conrod!

Edited by Big John on 16/10/2019 at 23:44