Ask Paul: Does my engine need an oil filter?

Q: I just purchased a 1978 Citabria 7ECA with a Lycoming O-235-C1. Just had my first oil change done — it has no oil filter! Just one, maybe two, screens.  Are these screens just as effective if I change my oil every 25 hours?  Should I add an oil filter? Is that even possible?  I run Phillips X/C and CamGuard. Your thoughts?

Jimmy Schramm, Tampa, Fla.

[Read more…]

Ask Paul: How should I handle chromed cylinder removal?

Q: When an engine with chromed cylinders comes into a shop with oil leaks and the source has been identified as thru bolts and cylinder base o-rings, how should the cylinder removal and reinstallation be handled? Also, is there any wisdom in turning the oil scraper ring upside down in chromed cylinder to help control oil consumption?

JAMES FINLAYSON, via email

[Read more…]

Ask Paul: What is causing mag drop?

Q: I work on a IO-360-MIA Lycoming engine. My problem is that the right mag has a drop of 220 rpm. I have done internal timings, engine to mag timings, ignition leads check and cleaned the plugs. I have done nothing to the left mag, and now the left mag is dropping to 210 rpm.

ANGI LISA CHAMBERS, via email

[Read more…]

Ask Paul: Why is my engine oil creamy?

Q: I am doing a 100-hour inspection on a Piper Aztec with TSIO 540 Lycomings using Shell 15/50 oil with 50 hours on the oil. They are both midtime engines on this photo plane. They fly six hours a day at low power settings. The left engine oil is black like it should be after 50 hours. The right engine oil is a light creamy color. Something is not right.

[Read more…]

Ask Paul: What’s causing vibration?

Q: I recently installed a new three-blade propeller in my Comanche 250 with an O-540 engine. After the first flight I noticed a vibration when I decrease the rpm to 2400 or below, so I had the prop dynamically balanced. This did not change anything. The engine still vibrated.

[Read more…]

Ask Paul: What’s the TBO on my engine?

Q: I have obtained a 1978 Bellanca 7GCBC with a Lycoming 0-320-A2B engine manufactured in 1977. I am attempting to learn more about this engine, including why the log book contains an entry at the 1,200 hour mark showing the engine as being “on condition” but I have been unable to determine why.

[Read more…]

Ask Paul: Fly more, get longer TBO?

Q: I bought my first plane, a 1981 Cessna T182RG, in May 2012. I have been flying this plane frequently and have put over 300 hours on it in the last calendar year. I can tell you that in 2005 it received a factory remanufactured engine from Lycoming and at the 1,000 hour mark got a complete top end overhaul. Now Lycoming shows the TBO at 2,000 hours, but I have found documentation from Lycoming that put the TBO at 2,200 hours providing you are running at 40 hours a month. For me that translates to the more you run the engine the more hours you can squeeze out of it.

[Read more…]

Ask Paul: What’s causing intermittent roughness?

Q: I am an European-based A&P with a customer who is experiencing intermittent roughness and loss of rpm (200) typically close to the top of climb on a long climb out. The roughness goes away once it is throttled back, and it does not occur all the time. The snag can’t be produced on the ground. The aircraft is just off annual check and had the 1,000 hours mag inspection carried out, apart from various other visual inspections, plus the routine other items.

I’ve thought about the possibility of a sticky valve, an issue in the carb venturi or some issue with the mags, but thought if it were any of these that the issue would be there all the time?

[Read more…]