Oil Analysis - Lycoming O-320-E2D - Opinions?

[mizer2167]

I've been trying to purchase a PA28 for about a month. I've been through two prebuys with issues each time.

But, I kept on and found one that made sense for my budget and mission, but the plane sat for 18 years from 2003 - 2021. Since then, someone bought it and put it back into service. They've flown ~35 tach hours the past two years total looking at the annuals. The seller said they've had two cylinders off in the last two years, but the engine looked good.

Along with the logs, they supplied this oil analysis below:

Give the oil analysis results, with the wear metals being high, would this be enough to keep you from moving forward with the purchase?

 

[455 Bravo Uniform]

Borescope the cylinders and look for corrosion or wear. Catch a visual of cam lobe if you can in this model engine. That’s the best you can likely do, other than also cutting and checking the oil filter if it’s been in service for many hours.

 

[Gary Ward]

Here's mine from 0-320 that I have been flying since it was a zero hour lycoming rebuilt for comparison. Sorry I don't like those numbers and probably would not buy that engine unless it was priced to be rebuilt.

 

[mizer2167]

Everything is ~double with PA28's pre-2020. This plane seems fairly priced for the market, but it's still not priced for a rebuild.

I checked and with my local shop it'll be around $33K if the crank and case are good. This plane is probably $13K-$15K overpriced if it needs a full overhaul, in my opinion, leaving some value to the hours left in the engine which is ~1,200 SMOH.

 

[Gary Ward]

Everything is ~double with PA28's pre-2020. This plane seems fairly priced for the market, but it's still not priced for a rebuild.

I checked and with my local shop it'll be around $33K if the crank and case are good. This plane is probably $13K-$15K overpriced if it needs a full overhaul, in my opinion, leaving some value to the hours left in the engine which is ~1,200 SMOH.

I would have never shown a buyer that oil report. No way I would fly it with those numbers. Sorry but I have never seen any numbers that high. Move on to another is my opinion.

 

[idahoflier]

The fact that the aircraft didn't fly for 18 years and only 35 hrs in the last two would give me pause. Really, find an aircraft you like that has been flown regularly and maintained properly. It may be priced higher than you like, but in the long run it will probably save you a lot of $ and time...

 

[OneCharlieTango]

The fact that the aircraft didn't fly for 18 years and only 35 hrs in the last two would give me pause.

This is the answer. Oil analysis almost never gives information that isn’t available more easily and reliably somewhere else. In this case, the history tells you everything you need to know: this engine will need a rebuild.

 

[bflynn]

Rebuild or at least some new cylinders. If the owner can be convinced of that and they drop their price, it's reasonable.

 

[MRC01]

A Lycoming O-320 has the cam on top and one that sits that long without being pickled will have a corroded cam and need to be overhauled. Price it accordingly, or find a different airplane.

 

[Domenick]

Was it in a closed hangar all the time it sat? If not, I'd run away on that alone.

The iron is very high. At the least, the cylinders had accumulated a rust patina which was wiped into the oil over the last 35 hours. Would be interesting to see the next oil change analysis.

If you are interested in the plane discounted for an engine overhaul, I'd tell the owner you MUST have a cylinder pulled by an A&P of your choice. Inspect the cylinder, cam, and crank. With a cylinder removed, a borescope will give you a good look. If I couldn't witness the work myself, I'd demand many photos and video of the borescoping.

 

[mizer2167]

I didn't proceed with the purchase. I did find another plane yesterday with a more recent Penn Yann overhaul that's been flying often as part of a flight club. It's more expensive by ~$10K of course, but I'll be flying behind a newer engine with fewer hours and another 10 hp, which never hurts. Trying to finalize the deal now, but feel better about a plane that's been flying regularly.

 

[bnt83]

Engines are a crapshoot. My O-320E2D with 2002 hours total time since new assembled in 1968 never made metal, just tired cylinders on it so we are overhauling it. Cam and lifters were in fair condition but eventually would have started eating each other but still 55 years old!

Just got my crankshaft back from shop in Tulsa so that was a huge relief. About $1.5k to overhaul the crankshaft I have VS $8.5K for a brand new one (aftermarket).

 

[Dan Thomas]

I've said it many times before, based on my experience with it: Ground-running an engine introduces a lot of moisture into the crankcase that then does not get boiled off during a flight. Some of it ends up between the cylinder wall and piston; I have found it there after a runup. That causes electrolytic action of the water and oil between the steel cylinder and aluminum piston, and you then find those elements in the oil. Chromium comes from the oil rings abrading on the roughened cylinder.

Environmental moisture is a small fraction of the risk represented by ground-running. Plenty of engines have sat for 20 or 30 years and been found to be fine inside, provided that the last time they were run was during a flight of decent duration.

 

[Dan Thomas]

With regard to engine corrosion while just sitting: Here's a video of a guy working on a 1929 GMC truck that has sat for 81 years without running. The engine was "stuck," but he got it loose with a mix of oils and solvents. He did the treatment a couple of times until the rings came loose and compression came up. The rings were likely stuck with carbon from oil burning in those old engines.

If environmental moisture was such a problem, it should have been rusted to a solid block of metal. He got it started, and it ran fine. Lots of smoke from the penetrating oils.

81 years. And it's not a desert there, either.