When I bought my 993 several years ago I was plagued by leaking plastic valve covers, doubtless due to aging. Despite replacement of the offending item (s) the problem persisted. I remember a very smokey traffic jam in the center of Strasbourg. Mistaken direction took me through not around! However, I changed servicing to my local PC Bournemouth, who replaced the faulty items, no problems since. Time may yet repeat. I am wondering if anyone has installed aluminum billet items made by Tarett Engineering (USA). They are pricey so not to be purchased willy nilly.
Richard.
Richard.