It didn't concern me until I changed the oil last spring. The motor had a definite knock that disappeared once I restarted it. For the last couple of years when the motor was run for a while it had a slight rattling sound at idle that has become more noticeable over time. I have been using MobilOne 10-40. Perhaps changing over to a conventional oil like Brad Penn will extend it's life until spring when I plan on checking the rod bearings. If it's worn beyond using standard bearing I will probably scrap the car unless I can find someone that wants a nearly rust free southern wagon for scrap price near Rochester,NY.