If there is a truism regarding piston aircraft engines, its this: Standard warranties arent. Our research and responses to a recent survey suggest that manufacturer and shop support quality is all over the map, literally and figuratively. For example, engine manufacturers generally enforce limitations in warranty provisions, without exceptions, right? Most of the time, yes, but evidence suggests exceptions are made.

At the other end of the spectrum, stories abound of local overhaul shops going beyond their warranties, usually as a way to ensure favorable reports about them spread among area pilots. But if they go out of business, where does that leave

you?

Despite those exceptions-or perhaps because of them-survey responses indicate youre better off addressing the obvious questions of expense and downtime by sticking close to home: If one shop did all the work, you know where to go if something isn’t right. But if you bought a factory reman, for example, and your local FBO did the installation, getting the right person to pay attention to a problem can be, well, a problem.

The good news is there are plenty of choices; the bad news is horror stories are alarmingly frequent. And, as many owners know, it seems no matter whose cylinders are bolted on, there’s no guarantee there wont be an AD or factory recall adding to the frustration.

“Standard” Warranty?

Most engines probably make it to their TBO with little more than oil changes and some spark plugs, or maybe a top overhaul, But a few engines roll over long before that. The reasons for premature overhaul can range from disuse to faulty assembly and-as both TCM and Lycoming owners have learned over the last decade-bad crankshaft batches. And even reputable engine shops with years in the business fall down and build the occasional lemon.

Thats what warranties are for. Experienced operators know a shops reputation for standing behind its work matters as much, if not more, than the quality of the overhaul itself. The table at right summarizes the published warranties available from Continental and Lycoming, along with a few of the well-known rebuilders. As this summary indicates, the warranty on your factory-remanufactured or field-overhauled engine depends not only on which manufacturers engine goes in your aircraft but also from whom you purchase it.

When we last looked at this topic in 1998, the basic engine warranty ran for six months, usually with some pro-rating to TBO. Now-thanks probably to more competition instead of better engines-most basic warranties run for at least 12 months. Exceptions include Lycoming, Penn Yan, Ram Aircraft and Zephyr but, even so, finding a shop willing to pro-rate its warranty beyond initial coverage to TBO is easy.

When the warranty clock starts ticking can be an issue, though. Lycoming, for example, starts the clock when the engine is shipped. Continental starts the warranty from the engines first date of operation or 180 days after invoicing, whichever is sooner. Other shops start counting at installation, at delivery or 30 days after the engine is shipped. So, if you buy an engine today for your experimental project, but might not fly it for a couple more years, beware.

All of this tripped up one owner: “A few years ago a friend of mine purchased a rebuilt engine from Mattituck for his Piper Arrow,” wrote Ken Paskar. “Due to various circumstances…all the repairs to the aircraft were not completed until almost eight months after taking delivery of the engine from Mattituck. The engine came with a six-month warranty from the date of delivery, so once the plane was airworthy, there was no longer any warranty left on the engine.”

You should also consider the cylinders being installed, as we’ll as accessories like magnetos, vacuum pumps and alternators. Some engine builders warrant these items, but not for as long as their original manufacturer. And here lies an easy trap for some and a lesson for others. we’ll let Peter Weiskopf of Hollywood, Maryland, tell the story.

“Three years ago my partners and I bought a factory-overhauled Lycoming O-320-E2D through H&H Propeller/Triad. After the first year, but before the second year, the Kelly starter died. Both Triad and the Lycoming factory said, One year on accessories, it doesnt matter that the starter manufacturer places a two-year warranty on it. We called Kelly Aerospace; real nice people. They shipped a starter