Incorrect engine timing is a serious problem that should be resolved as quickly as possible. When your timing is off, the pistons are allowed to slam into the valves. This can cause serious damage to your engine, maybe even completely destroying it. Should you damage your engine you may be forced to replace your valves and engine head, a costly repair to say the least. Breaking valves or pistons can also cause major mechanical problems. Should you find your timing is off you should have it repaired as quickly as possible.