just taken it around the block and given it a few revs but there very slight steam now, lifted bonnet but cant pinpoint where it coming from, doesnt seem to be any residue of anything in there (water, oil etc) but strong smell of diesel? also which i didnt mention before was a knocking noise from dash above from stereo, but not heard that today, happens every so often?? sorry its a 1994 300TDI thanx