Maintenance - Scheduled Service

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Whether you choose to do it yourself or have us do it, there is nothing more important for your aircraft’s engine than regularly scheduled oil changes. We’ve been overhauling engines for years and if there’s one thing we’ve learned after tearing apart thousands of engines it’s that those which receive regularly scheduled oil changes have far less problems and are much more likely to go TBO or beyond than those that do not.

How Often Should You Change Oil

Every engine manufacturer will tell you that at a minimum you should change oil every 50 hours if you have an oil filter, every 25 hours if you don’t. If you operate under severe conditions, or you run a high time engine, you should consider shortening the oil change interval. Manufacturers will also tell you that you should change your oil every 4 months, even if you have only a few hours on the oil. That means you should change your oil, at the very least, 3 times a year.

Our humid west coast is especially tough on engines. It's one of the worst climates for internal engine corrosion. As oil ages, it can take on moisture which then reacts with acids generated by the combustion process to create some very nasty corrosive elements inside your engine. Both Lycoming and Continental publish explicit service documentation regarding oil change intervals. Lycoming engineers feel so strongly about the subject that they issued a Mandatory Service Bulletin on oil change intervals.

Lycoming Mandatory Service Bulletin - Oil Change Interval: SB480E

Continental Care and Feeding Article on Oil: Oil

What Oil Should You Use

We’ve been using and recommending Shell Aviation Oils for years. In most cases we recommend single weight oils as they have proven superior at protection, especially in our environment. Some engines operated under severe conditions may benefit from multi-grade oils, but not all engines do well with semi-synthetic multi-grade oils. Obviously, your POH will be the definitive guide on engine oil types and weights, but you should also read the service bulletins regarding approved engine oils by both Lycoming and Continental. They may be more up to date than your POH and may account for improvements in oil that the authors of your POH could never have anticipated.

Lycomng Service Instructiion - Recommended Oil: SI1014

Continental Service Information Letter - Recommended Oil : SIL99-2B

Changing Your Own Oil

Changing your own oil is a great way to become familiar with your aircraft and save some money too. Once you know how, it’s relatively easy although you will require some specialized tools like an oil filter cutter, screen or filter washing facilities, lock wire pliers, a torque wrench capable of measuring down to 10 ft pounds, used oil containers and washdown solvents for cleaning the engine afterwards.

If you’ve never done an aircraft oil change before consider doing an owner assisted one with us. We’ll walk you through the entire process and give you the knowledge needed to do it on your own. There’s a lot more to it than there is to an automobile oil change. For starters, you’ll have to know how to use lock wire pliers and how to properly apply lock wire to the filter or screen retainer bolt. After one or two owner assisted oil changes, you should give you the skill and confidence necessary to take the job on, on your own. And, if you ever run into problems, we’re always available to help.

Our owner assisted oil changes are entered in your logbook as such which provides full documentation that you have acquired the skills necessary to perform them solo.

Why Do Aircraft Oil Changes Cost More Than Car Oil Changes?

There are a huge number of reasons, here's just a few: First, aircraft engine oil costs about 3 times as much as automobile oil. Second, your car’s engine isn’t FAA or Transport Canada certified for flight so just about anybody off the street, at 7 bucks an hour, is certified to change its oil.

Third, cars are built for rapid service, airplanes are built for aerodynamic efficiency – the two are diametrically opposed. Fourth, you won’t find any auto service center cutting open your oil filter then spending 15 minutes analyzing its media and contents . Fifth, nobody in the auto sector ever installs an oil filter with a torque wrench and lock wire. Sixth, we’ve yet to see anyone in the automotive sector inspect your car’s prop, hub and spinner for cracks, wear and leaks. Seventh, automobiles do not have engine cooling baffles to inspect and check for correct orientation once the hood is closed.

We could go on, but you get the point. Servicing airplanes is more complex and the outcomes of failing to do it right are much more dramatic. You simply cannot compare servicing an airplane to servicing an automobile.

What To Expect From a Valley Aero Oil Change

An aircraft oil change requires a lot of attention to detail. We use a checklist at every oil change we do to ensure we leave nothing to chance. For a basic oil change on a single engine aircraft the steps in our typical service are as follows:

• Warm up the engine to ensure complete draining of the old oil
• During engine warmup, listen for any unusual anomalies and run a mag check
• Check braking action and parking brake under load
• At engine shutdown check for appropriate engine shutdown rpm rise and check mag grounding
• Remove cowling as required for access to the engine for a visual inspection
• Inspect cowling for wear
• Check cowl mounts for security
• Visually inspect engine mounts
• inspect for visible signs of hard landings
• Check the dipstick level prior to draining to assess the color and viscosity of the oil
• Drain the oil
• Take a mid-stream sample if customer requests an oil analysis
• Remove oil filter, cut open and lay out media
• Pass a strong magnet over media looking for ferrous metal particles
• Wash media and filter remains looking for non-ferrous metal
• If the airplane has an oil screen, remove and check for particles by washing and filtering remains
• Install new oil filter, apply DC-4 to filter gasket or re-install screen with new crush gasket and lockwire in place
• Visually inspect cylinders and engine for cracks, leaks, failed seals, etc.
• Service the battery – neutralize acid corrosion if found in the battery box
• Visually inspect hoses, belts and engine accessories
• Visually inspect magneto exterior and spark plug leads
• Inspect engine baffles for wear, wrong orientation or cracks in metal components
• Visually inspect exhaust system for visible signs of leakage
• Physically check exhaust components for security
• Visually inspect prop and prop hub and spinner for wear, leaks, cracks or movement
• Check and adjust tire pressure
• Refill engine with oil of customer’s choice
• Ensure aircraft is secure for a post oil change runup
• Runup aircraft, check idle speed and idle mixture at shut down
• Check for leaks
• Complete inspection for tools or any other foreign objects left in engine compartment
• Recowl the engine (if required)and double check cowl security
• Check all light bulbs
• Clean all fingerprints and other signs of service from fuselage
• Make logbook entry stating service performed and parts and fluids added