The current ride is down for maintenance.

I’m really pretty anal about maintenance on the Cessna. My philosophy is that if something breaks after taking off into IFR conditions, it’s bad thing. So proper maintenance is a must. The only maintenance I ever defer is non-critical items. Interior trim, for example.

I change the oil and filter between 30 and 35 hours. Many people run 50 hours. And some don’t change the filter at every oil change. Not only do I change the oil and filter but I take an oil sample and send it off for analysis. And I cut the filter open and inspect the filter for metal.

A couple months ago I hit the 500 hour mark since the engine was completely overhauled. The magnetos require and inspection and rebuild at 500 hours. So the mags came off when I was changing the oil and filter. I also took the opportunity to replace all 12 sparkplugs.

At the next oil change, ferrous metal was found in the filter. The oil analysis report also showed “slightly elevated iron” in the sample. Lynn, my A&P (Airframe and Powerplant mechanic) said the amount of metal wasn’t enough to ground the plane but it did warrant watching. I sent the metal to a lab and then ran a number tests on it and the report was that it was consistent with the crankshaft.  Lynn feels it’s almost a certainty that it’s the camshaft.

So my plan was to fly a shorter cycle and change the oil at about 15 to 20 hours and see what happens.

It was a VERY stressful 15-20 hours. Every time the engine made the slightest noise, I was looking for a place to land. And engines make a LOT of noise.

After my last trip down to Greenville, I changed the oil (19 hours since the last change). A lot more metal in the filter this time. The oil sample shows the iron dropping back down to the “normal” range.

I sent the filter out to Firewall Forward have the metal analyzed under their scanning electron microscope and they said it most likely came from the camshaft.

While a catastrophic failure was unlikely and I could keep flying, the metal being produced would be damaging other parts of the engine. So I made the call to ground the plane.

I was way past the warranty on the overhaul from 5 years ago (2 year warranty) so I had to pick a shop to do the teardown, figure out where the metal is coming from and fix it. I could send it back to Penn Yan which is who did the previous overhaul but since it only made it a quarter of the way to 2,000 hour TBO, I wasn’t happy with them at this point. So on the recommendation of Lynn, I’m going to give Poplar Grove Airmotive a shot. They’re only about 30 miles away and they’ll pick it up and deliver it for free (which usually costs about $300 each way). And since they’re close by, I can drop by and check on the progress.

The biggest downside is that this is a horrific, unexpected expense. Initial estimates are $7,500 for the low side and lots, lots more if it turns out to be the crankshaft. And that doesn’t include the cost of removing and reinstalling the engine.

This morning we pulled the airplane over the Lynn’s shop and removed the engine. We had it out by about noon. Poplar Grove will pick it tomorrow. They say it’ll take about 3 weeks. I’m hoping for a (good) prognosis next week.

Removed engine

What is now a glider.

The thing that really sucks is that with regular maintenance and normal use, this engine should be able to have gone 2,000 hours.