So are you saying that the inferior valves are still available and will cause that kind of wear within 500 miles? If so why exactly? I know you don't dictate what's available but it seems bizarre that Nissan would continue to offer a valve that will just fail. I don't doubt that the original valves that came out were inferior, my car was built in 05/89 if I recall correctly, but you're saying that it's possible to still buy the inferior valves? Just making sure I understand is all.
