Is there a limit to how much oil consumption is too much? This episode, Mike, Paul, and Colleen answer this important question. Email podcasts@aopa.org for a chance to get on the show.

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Full notes below:

Jim has a Cardinal with 3,000 hours on the engine. Everything looks good, except that the oil consumption has increased substantially. They tried the ring flush procedure, and saw the fluid coming out of the carb intake and exhaust manifold. The second cylinder took an immense amount of effort to pull the prop through. They took that cylinder off, and found that the oil control ring had a lot of crud. Mike said he wouldn’t get too invasive in order to solve the problem. It’s not a safety of flight issue. They suggest replacing the cylinders only if the oil consumption bothers Jim and his partner. Jim’s partner suggested also overhauling the bottom end with cylinder changes. They advise against it, instead looking at the cam when the cylinders are off. Mike wonders if the ring flush was done wrong. None of the fluid should come out of the exhaust or carb. He and Paul said they’ve never seen fluid come out of the valves. They recommend trying again.

Nicolas and his partner disagree on how often they should change the oil on their Grumman Tiger. His partner wants to change the oil before the winter, when they usually only fly a few hours, and then again in the spring, when they fly around 30 hours. Mike said the oil change intervals are inexact. As the airplane is flown, the oil gets increasingly corrosive. He suggests not letting the airplane sit with old oil throughout the winter. So that’s when he would change it. He’s wondering if he can avoid changing the oil in the spring after only flying for seven hours over the winter. The hosts agree that it’s probably fine not to change the oil at that point. They recommend also getting a dehydrator to keep the inside of the engine dry.

John has a twin Cessna with one engine that quits when it’s cold. Mike said the fuel pressure at low rpm isn’t high enough. Or the idle mixture isn’t rich enough, or there’s something wrong with the flow divider. The easiest and cheapest thing to do is to adjust the fuel pressure or the idle mixture on the fuel control unit. Paul said his Cirrus does the same thing in winter. He thinks it’s the fuel divider.

Cheryl has a Skycatcher with a window tint and she is concerned about its legality, and whether it should be noted in the airframe logbook. So long as it doesn’t inhibit the view, the hosts think it’s fine.