How far can you go with preventative maintenance? The hosts discuss this, plus oil-soaked plugs, a strange fuel smell, morning sickness, and more. Email podcasts@aopa.org for a chance to get on the show.

Full notes below:

Lamberto has a 152 with oil soaked plugs, and is having to clean them every 25 hours. He wants to fix the problem, not simply deal with it. His mechanic suggests a harsh chemical. He’s tried new plugs without success, the hosts agree his BY plugs are the best for oil-fouling anyway. A solvent won’t help, Mike says. He suggests a ring wash, which involves filling the cylinder with a mild solvent, then pulling the prop through the combustion cycle. That forces the fluid through and cleans little by little. If you try to pull the prop through it’s probably too late and the cylinder needs to be removed and the rings probably replaced. Colleen likens it to flossing.

Darin is curious about how far he can push preventative maintenance. His thinking is that if you can clean and gap spark plugs then you should be able to do the same to fuel injectors, and so on. Mike says it’s not entirely clear. The FAA has issued a letter of interpretation basically saying that the list in Part 43 is a list of examples, not an exclusive list.

Cristopher flies a 172XP in a club in Germany and wants to fly beyond TBO, and also solve an oil issue. He thinks it’s coming out of the induction system drain. The only way that can happen is via the intake valve. They recommend borescoping the cylinder to confirm the leak.

Callum has a Bonanza and smells fuel in the cockpit when transitioning to lean of peak. Paul suggests checking the throttle body area behind the panel. The mechanical changes when you lean can cause it. Mike knows of another airplane where this has happened, and they isolated it to a leak in the fuel selector. When you lean a bunch of fuel goes back through the return lines, he said, and any leak could show at this point.

Jason has a 182 with an O-470 with a cylinder that is acting up on start when it’s cold. His engine monitor shows very low EGT when starting, and takes as much as a minute to 90 seconds to come to temperature. The CHTs are also much lower. The hosts agree that he definitely has the symptoms of morning sickness, and it’s time to ream it.