Hello! I have a Z3M, S50 engine! My Vanos exhaust solenoid again leaking...I was replaced o-rings before 4500 km!I was again put Viton o-rings...One old o-ring(exhaust/ bigger) was bad ! Should I put a thicker o-rings? And how much thicker? And is better silicone or viton? I mean factory nitrile is bad... And should I put silicon(or other) around the solenoid to not play?Or some shims? Thanks!