Any valve can burn! Lack of HEAT transfer is most common reason for failure. However a defect in the valve can cause the valve to burn as well.
MOST MB exhaust valves are sodium filled to help with heat transfer.
Since most engines have hydraulic lifters now, we see less burnt valves than on earlier engines.
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)