How Often Should You Change Aircraft Engine Oil?

How to Keep a Post-Flight Discrepancy Log

Send us questions by commenting below or emailing John & Jeff at: Podcast@SignatureEngines.com How to Keep a Post-Flight Discrepancy Log Most engine problems don't show up overnight — they trend. Keeping a simple post-flight discrepancy log is how you catch them before they ground you, or worse. John and Jeff walk through the habit they wish every owner and pilot would adopt: at the end of every flight, write down what you noticed. A new noise, a vibration, a temperature that ran a little higher than normal — or nothing at all. Even "none noted" with the date and your initials is worth writing, because it gives the next pilot and your mechanic a baseline to compare against. The guys explain why this matters most on aircraft with multiple pilots, where nobody wants to be the one to "make it a thing," and how that silence lets small issues turn into expensive ones. Jeff shares a real example: a young pilot who heard a popping sound out of the left engine for about two months and brushed it off — until they pulled the cowling and found an exhaust stack hanging an inch and a half loose. Hot exhaust gases that close to a wiring harness can melt insulation and kill power to the engine, and a stack that fully breaks loose becomes a hazard on the ground. The fix, caught early, would have taken minutes. By the time it was found, it was a near miss. The episode is about building the awareness and the paper trail that catches problems while they're still cheap. In this episode, we cover: - Why a written post-flight squawk log beats relying on memory - What to write when nothing went wrong (and why "none noted" matters) - How trending small symptoms reveals real engine problems - The communication gap on multi-pilot aircraft, and how to close it - A real-world case: a popping sound that was a hanging exhaust stack - What can go wrong when an exhaust stack hangs near a wiring harness - Why looping in your mechanic — or another mechanic — pays off - How to give your A&P the history they need to actually diagnose an issue If you fly behind a piston engine, this is one of the cheapest habits you can build to keep your airplane airworthy and yourself safe. TIMECODES 00:00 The post-flight habit nobody wants to do 00:27 Why "I think I felt this 3 months ago" is too late 01:18 What to write down — even when nothing happened 02:08 The multi-pilot communication problem 03:23 The popping sound that was a hanging exhaust stack 05:16 What a loose exhaust stack can actually do to your engine 06:00 Call your mechanic — or another mechanic Get in touch! Web - SignatureEngines.com Email - Podcast@SignatureEngines.com YouTube - youtube.com/@SignatureEnginesInc

How to Preflight a Piston Engine the Right Way

Send us questions by commenting below or emailing John & Jeff at: Podcast@SignatureEngines.com How to Preflight a Piston Engine the Right Way A real preflight inspection is more than opening the oil door and checking the dipstick. John and Jeff walk through what they actually look for before every flight — and what most pilots miss. Vibration is the number one enemy of a piston aircraft. Motor mounts crack, components loosen, and parts break between flights. A magneto that ran fine yesterday can be dead today. You won't catch all of it on a walkaround, but you'll catch a lot more than you think if you slow down and know where to look. John and Jeff start under the aircraft — looking for fresh oil, fuel, or hydraulic leaks on the ramp or hangar floor — then work up through the cowl, the propeller, the intakes, and the belly. They talk through the bird nests and mud dauber nests that show up after the plane sits, why a piece of cardboard under the airplane is one of the cheapest diagnostic tools an owner can have, and why a constant-speed propeller deserves more than a glance. Then they move into the cockpit, where checking the throttle, mixture, and prop control for freedom of movement before start can flag a problem before you ever turn the key. In this episode, we cover: - Why looking under the aircraft is the first step, not the oil door - How to tell normal seepage from a developing leak using a piece of cardboard on the hangar floor - What mud daubers and birds get into — breather tubes, carb intakes, pitot — and how to spot the trail - Why you should open the cowl when you can, and what to look for when it's open - How to check a constant-speed propeller for leaks and security on preflight - Why the windscreen, nav lights, and landing lights matter even on a day VFR flight - What a sticky throttle, mixture, or prop control can tell you before engine start - Why a magneto can fail between flights and how the runup catches what the walkaround can't A thorough preflight inspection is the cheapest insurance an owner has — and the difference between catching a problem on the ramp or finding it in the air. TIMECODES 00:00 The preflight habits that separate good pilots from bad ones 00:36 Why most pilots only check the oil and stop there 01:02 Start under the aircraft: looking for oil, fuel, and gear leaks 01:21 Open the cowl when you can — what breaks between flights 02:12 Vibration, motor mounts, and why piston aircraft parts fail 02:31 Inspecting the propeller and checking the intakes for nests 03:00 Mud daubers, birds, and what shows up after the plane sits 04:11 Using cardboard under the aircraft to track leaks over time 04:54 Don't skip the windscreen, nav lights, and landing lights 05:28 In-cockpit preflight: throttle, mixture, and prop control freedom Get in touch! Web - SignatureEngines.com Email - Podcast@SignatureEngines.com YouTube - youtube.com/@SignatureEnginesInc

How to Inspect an Aircraft Oil Filter the Right Way

Send us questions by commenting below or emailing John & Jeff at: Podcast@SignatureEngines.com Why Oil Analysis Alone Won't Save Your Engine Oil analysis is an indicator, not a verdict on airworthiness. John and Jeff break down why the report is just one tool, and what you have to do alongside it to actually know what's happening inside your engine. More owners and pilots are leaning on oil analysis like it's the final word on engine health. It isn't. Both Lycoming and Continental tell you to inspect the oil filter — cut it open, flush the media, run a magnet through it, and look at what your engine is actually shedding. John and Jeff walk through the full routine: how to take an oil sample correctly (always midstream, never the first or last of the drain), why letting the drained oil settle in a clean five-gallon bucket and filtering the last bit through a coffee filter tells you what's really sitting in the sump, and why pictures of every filter and screen inspection beat trying to remember what last quarter looked like. They cover the difference between ferrous and non-ferrous debris, why a high iron reading after a winter of sitting often just means corroded cylinder walls getting scraped clean, and the Lycoming brass bushing AD covering engines built between 2009 and 2015. They also get into the part most owners skip entirely — the finger screen — and why it catches the big chunks an oil filter never will. If your filter has a bypass valve and you're making metal between long oil changes, that material can route straight to your bearings without you knowing the bypass ever opened. In this episode, we cover: - Why oil analysis is an indicator, not an airworthiness determination - How to take an oil sample correctly — midstream of the drain, every time - Cutting open the oil filter, flushing the media, and running a magnet through the debris - Letting drained oil settle and filtering the last 5% through a coffee filter to see what's really in the sump - Why you need to photograph every filter and oil inspection, not rely on memory - Telling ferrous from non-ferrous debris and what each suggests - Why finger screens catch failures the oil filter will miss - The Lycoming brass bushing AD on engines built 2009–2015 and why you watch the oil for brass - How shorter oil change intervals reduce the risk of the filter bypass dumping debris into your bearings For piston aircraft owners who want to catch problems early instead of being surprised by them — this is how you actually read what your engine is telling you. TIMECODES 00:00 The oil sampling mistake that wrecks your data 00:38 Why oil analysis is an indicator, not airworthiness 01:35 How to inspect your oil filter the right way 02:28 Reading what's left in your drained oil 03:20 When elevated readings don't mean engine trouble 04:07 The catastrophic failure oil analysis missed 05:17 Taking samples midstream and staying consistent 05:55 High iron after winter — what it usually means 06:48 What chrome, nickel, aluminum, and molybdenum tell you 07:39 Lycoming and Continental limits on filter debris 08:12 Saving filter elements in baggies for comparison 08:51 Why finger screens still matter and why mechanics skip them 09:39 Filter, screen, or both — what to inspect and why 10:31 The Lycoming brass bushing AD (2009–2015 engines) 11:14 What the finger screen catches that the filter won't 11:37 Why the filter bypass valve is the hidden risk Get in touch! Web - SignatureEngines.com Email - Podcast@SignatureEngines.com YouTube - youtube.com/@SignatureEnginesInc

How Often Should You Change Aircraft Engine Oil?

Send us questions by commenting below or emailing John & Jeff at: Podcast@SignatureEngines.com How Often Should You Change Aircraft Engine Oil? The 50-hour aircraft engine oil change interval in your POH was written for flight schools flying constantly — not for the owner who flies a few hours a month and parks the plane. John and Jeff break down what the book actually says and what most owners miss. Aircraft engine oil isn't automotive oil. It's only about 6 to 7% additives compared to 13 to 16% in conventional auto oil, and those additives — the ones fighting moisture, acids, sludge, and carbon — start breaking down around 20 to 25 hours. After that, the oil still lubricates, but it's no longer protecting the inside of your engine from the corrosion cycle that runs every time the crankcase heats up and cools down. That's how camshaft and lifter pitting starts on Lycomings, and it's why John and Jeff see rust inside engines from owners who swear they fly regularly. The piece almost everyone overlooks is the calendar rule: change the oil every four months regardless of hours. Two hours on the engine in four months still means it's time. The hosts walk through why "regular use" isn't ten hours in one trip followed by three weeks parked, why active preservation only happens in the air at temperature, and why the difference between a 30-hour and 50-hour oil change is one extra change per 100 hours — cheap insurance against an engine teardown. In this episode, we cover: - Why the 50-hour interval was written for flight schools, not typical owners - The 4-month calendar rule in the POH and what it actually requires - How aircraft oil additives break down by 20 to 25 hours - Why aircraft oil is only 6 to 7% additives versus 13 to 16% in automotive oil - How condensation, acids, and the crankcase greenhouse effect cause internal rust - Why camshaft and lifter pitting hits both Lycoming and Continental engines - Why ground runs and taxiing don't count as active preservation - The 30 to 35 hour oil change recommendation and pulling the filter every 100 If you fly less than 200 hours a year, this episode helps you stop a corrosion problem before it turns into a top overhaul. TIMECODES 00:00 What the POH 4-month oil change rule actually says 00:30 Is the 50-hour oil change interval right for your flying? 01:33 Why aircraft oil only has 6 to 7% additives 02:42 How rust starts inside engines that "fly regularly" 04:18 Why 30-35 hour oil changes are cheap insurance 05:16 What "regular use" really means for piston engines 06:22 Humidity, condensation, and the crankcase greenhouse 07:16 Camshaft and lifter pitting on Lycoming vs Continental 08:11 Final recommendation: 30-35 hours, every third change pull the filter Get in touch! Web - SignatureEngines.com Email - Podcast@SignatureEngines.com YouTube - youtube.com/@SignatureEnginesInc

How to Properly Drain Oil From Your Aircraft Engine Sump

Send us questions by commenting below or emailing John & Jeff at: Podcast@SignatureEngines.com [Podcast@SignatureEngines.com] How to Properly Drain Oil From Your Aircraft Engine Sump If you own a prop plane and you've never pulled the quick drain out of your oil sump, you might be hiding water, metal, and sludge at the bottom of your engine — and getting clean oil analysis reports that aren't telling you the truth. In this first episode, John and Jeff break down the quick drain valve — the threaded plug at the bottom of the oil sump that lets you connect a hose and drain oil without making a mess. It's one of the most common parts on small piston aircraft, and one of the most misunderstood. They explain why the convenience comes with a catch: the plug threads stick up an eighth to a half inch into the sump, creating a dam that traps water, heavy metals, and combustion byproducts below the drain level. That trapped material sits there change after change until it finally rises high enough to come out, which is often when an owner suddenly sees red and yellow flags on an oil analysis report that looked fine for years. They walk through the right maintenance rhythm for general aviation piston engines: use the quick drain for routine oil changes every 30-35 hours, but every third change — roughly every 100 hours — pull the entire valve out of the sump with the warm oil still in there and let the volumetric pressure flush the bottom clean. They also cover when to replace the plug entirely (every 4-5 years, around $100-$130), why the FAA no longer permits overhauling them, the safety-wire hole most people miss, and one real-world story of a socket found blocking a customer's drain. In this episode, we cover: - Why the quick drain plug threads create a sludge trap at the bottom of your sump - The 100-hour rule for fully removing the quick drain, not just draining through it - How a partially blocked quick drain skews your oil analysis results - What to do with the warm oil still in the engine when you pull the plug - Why the FAA stopped allowing overhauls of quick drain valves - The 4-5 year replacement interval and what a quality replacement costs - Why the safety wire hole on the plug matters and what happens if you skip it - Signs your quick drain seal is failing — slow drips, slow drains, rounded threads This one's for prop plane owners and pilot-mechanics who want their oil analysis to actually mean something, and who'd rather spend $100 on a new plug than find out the hard way what a failed one does in flight. TIMECODES 00:00 Why You Should Pull Your Quick Drain Every 100 Hours 00:26 Welcome to Keep Those Props Turning 00:35 What a Quick Drain Is on a Prop Plane Engine 01:44 The Socket in the Sump and Other Quick Drain Failures 02:13 How Quick Drain Threads Trap Water and Metal in Your Oil 03:00 Why Your Piston Aircraft Oil Analysis Suddenly Shows Red Flags 03:52 The Right Way to Drain Oil Every 100 Hours 04:06 Drain Hole Diameter and How It Affects Oil Flow 04:48 When to Replace Your Quick Drain Valve and What It Costs 05:36 Why the FAA No Longer Allows Quick Drain Overhauls 06:05 Safety Wiring Your Quick Drain Plug 06:39 What Happens If a Quick Drain Fails in Flight Get in touch! Web - SignatureEngines.com Email - Podcast@SignatureEngines.com YouTube - youtube.com/@SignatureEnginesInc