Sump was changed before i got the car and it was sealed with blue sealant - is this blue sealant alright or do i need special sealant? I see 3 plates on the block just below the turbo with 4 studs in each plate. The plate closest to the turbo is weeping oil from the bottom 2 studs when ticking over but when revved out more oil comes out. Iv done 50-60 miles and lost 1.5l of oil - the whole bottom of the car is covered. I can't see anywhere that would leak that amount of oil is there somewhere that is common for 850's the leak that muck oil from? Also what is behind those 4 plates? I don't want to take them off without knowing what I'm up against incase I end up with a pile of bearings and springs on the floor!