I have a Seat Altea that I am replacing the valve stem seals on. To get to them you have to remove the cam which is in its own ali carrier casting from the head. It is bolted to the head through the bearing caps. The assembly is sealed with a bead of sealant that runs in a groove in the carrier. This groove is about 2mm wide and deep. When I removed the carrier I found this sealant to be brittle as opposed to a silicon sealant. The part number is D188800A1. According to google and it seems Seat dealers, it is no longer available or as the dealer said its on back order. There was some available in USA but the delivery would be middle of May! As I said it sets hard and it seems it is the stuff they use to seal the electronic units as the manual points to the Electronic parts catalogue for info. So what would you chaps recommend. It seems most stuff is silicon based but is there anything that would react like the original.?