approx cost to repair, or do i need another engine? on 2005 Mercedes-Benz C230

car had oil leak, went to bennetteworld,said it needed gasket cover replace, did that, now car want start i was told my another mechanic that the timing chain had jumped and bent valve-

Asked by for the 2005 Mercedes-Benz C230
If the headgasket was replaced, the timing chain tends to jump at the crankshaft sprocket and timing may be off if proper tools weren't used. Was compression checked? If only the valve cover gasket was replaced then the chain shouldn't have jumped.