Dear Tom and Ray:
When I was filling my engine with new oil, pine needles fell into the oil and are now in the engine. The little stem that went in had three needles on it, each approximately 4 inches long (long-leaf pine, Pinus Palustris). Is this going to hurt my engine? My car is a 2011 Honda Accord EX, 4-cylinder. — Marissa
Tom: Oh, good thing it was the Pinus Palustris, and not the dreaded Pinus Enginus Rebuildis.
Ray: Your engine’s going to be fine, Marissa. There are several things that can happen to these needles, and none of them is harmful.
Tom: The oil fill on this car is right on top of the valve cover. Most likely, the pine needles are just sitting there on top of the valve train, soaking up oil and doing no harm. And they may stay there for years, or decades, without affecting anything.
Ray: If they do get in the way of one of the cams, they’re soft enough to just be pulverized. Remember, all the engine parts are metal. They’d make short work of these three little pine needles.
Tom: Then the pulverized pine needles would get circulated with the other oil that gets sent up to the valve train, and the entire top of your engine will have a nice, fresh scent. Sweet, huh?
Ray: Eventually, you’ll get rid of these needles in one of two possible ways, Marissa: If they get ground up, their crushed remains will end up either at the bottom of the oil pan or in the oil filter, and will be removed next time you change your oil.
Tom: Or, 10 years from now, when some mechanic removes the valve cover to replace a gasket, he’s going to find a 6-inch Christmas tree growing in there. Either way, it’s nothing to worry about, Marissa.