If it is a burnt valve it isn't going to get better. Performance and fuel mileage will suffer. After all, you are running on one less cylinder. Burnt valve or a bad head gasket are not related. Two complete separate issues. Once the head is removed to repair the valves, a new head gasket must be used. Only good for one time crush. On a side note, how did you know that the b2 piston in trans is bad on my old Mercedes. I've ordered a manuel but have not received it.