Asking advice on continental engine at annual?

[Bill Greenwood]

My 1988 Be 36 TC is in for annual. The engine is Cont TSIO 520 UB, about 800 hours on it.

In the oil change we found some metal in the filter, not much, but more than a trace. It is all the same, about 10 small iron or steel spikes or slivers, they are perhaps 1/32 of an inch long and half that wide. They taper from a bigger base to a point, like a spike. They are sort of sharp sided, not round, and are magnetic, and just dark in color like the oil. There is no aluminum flakes or bearing metal or bronze,no polished or chrome, just these things. We did an oil analysis but don't have the results back yet. I don't expect the analysis to show much as these are too large to make it through the oil filter.

My A & P has 40 years experience and is not sure what they are. It could be a tappet or a gear, he doesn't think it is from a camshaft.

The standby backup generator is worn out, even though it still works, but there no evidence of the gear of where it mounts missing any metal.

Any good advice or educated guess? A full overhaul is $42,000, and I don't want to do it just on guess work. He suggests flying another 20 hours and then checking the filter again.

I may also try sending some of the metal itself into be checked by Cont or the oli analysis people, neither of which do I have complete beliefe in.

Compression is good, he did find ignition timing was about 2 * off. It starts and runs well.

Thanks

[1TJ]

My 1988 Be 36 TC is in for annual. The engine is Cont TSIO 520 UB, about 800 hours on it.

In the oil change we found some metal in the filter, not much, but more than a trace. It is all the same, about 10 small iron or steel spikes or slivers, they are perhaps 1/32 of an inch long and half that wide. They taper from a bigger base to a point, like a spike. They are sort of sharp sided, not round, and are magnetic, and just dark in color like the oil. There is no aluminum flakes or bearing metal or bronze,no polished or chrome, just these things. We did an oil analysis but don't have the results back yet. I don't expect the analysis to show much as these are too large to make it through the oil filter.

My A & P has 30 years experience and is not sure what they are. It could be a tappet or a gear, he doesn't think it is from a camshaft.

The standby backup generator is worn out, even though it still works, but there no evidence of the gear of where it mounts missing any metal.

Any good advice or educated guess? A full overhaul is $42,000, and I don't want to do it just on guess work. He suggests flying another 20 hours and then checking the filter again.

I may also try sending some of the metal itself into be checked by Cont or the oli analysis people, neither of which do I have complete beliefe in.

Compression is good, he did find ignition timing was about 2 * off. It starts and runs well.

Thanks

It sounds like the cam or lifter(s) to me. Pull a a few lifters on one side to check the cam and lifter surfaces. Refer to Continental SID 05-1 before doing anything expensive.

Ed

[Bill Greenwood]

Thanks, Ed. I asked the A&P about looking at the cam and lifters and he says it is not easy to get access to them on this engine.

I phoned the factory, got a nice guy who also owns a Bonanza,, and he says tappet wear usually shows more as a shaving, and I wouldn't say that is what these look like. He thinks is could be starter drive or an accessory.

[1TJ]

Lifters bits look like coffee grounds, cam & starter adapter spring bits like needles. It could be your adapter. I hope it is!

Ed

[Bill Greenwood]

I pulled the particles off the magnet and took a better look. They look more like flakes and are smaller and shiny than my first impression.
Oil analysis found slightly high iron and a little nickel.

The lifters are not readily accessable on this engine.

I think I will fly another 10 hours or so, and recheck.

But, if there is more metal then, I'll still be considering an overhaul. Ouch $$$$$$$$!

[1TJ]

Can you attach a picture?

Have you recently changed your starter?
Have you changed to Aeroshell 15W-50 or PLUS in the last year?
You may want to pull your starter adapter and have a peak.

One exhaust lifter should be 2-3 hours on and off. Fortunately with Continentals you don't have to remove the cylinder.

You may want to try a high dose of Camguard if you are going to run it.
Ed

[Bill Greenwood]

I am not good with Iphone computer stuff ,but will try to get a photo. I actually used to be a commercial photographer,but that was in the film days .

I used Exxon Elite 20w-50 oil up until about 25 hours ago when we replaced a cylinder and changed to mostly Phillips mineral oil. I have not used Shell 15-50 in a number of years.
Do you consider 15-50 to be bad, and if so why?

I have not changed the starter adapter, I think it was pulled and inspected about 2 years ago as part of replacing a plugged oil hose.

I may try Camguard. I thought it was mainly to prevent corrosion and it is very dry here in Colorado.It probably can't hurt except being expensive.
Thanks

[1TJ]

I am not good with Iphone computer stuff ,but will try to get a photo. I actually used to be a commercial photographer,but that was in the film days .

I used Exxon Elite 20w-50 oil up until about 25 hours ago when we replaced a cylinder and changed to mostly Phillips mineral oil. I have not used Shell 15-50 in a number of years.
Do you consider 15-50 to be bad, and if so why?

I have not changed the starter adapter, I think it was pulled and inspected about 2 years ago as part of replacing a plugged oil hose.

I may try Camguard. I thought it was mainly to prevent corrosion and it is very dry here in Colorado.It probably can't hurt except being expensive.
Thanks

25 hours after you had cylinder work done a mid time engine is making metal???????

[Bill Greenwood]

One cylinder was replaced with a rebuilt one due to a crack near the exhaust port. Engine time is about 700 hours.

I took a look at the SIB, thanks for that info. I am considering asking the A&P to open it up enough to check a lifter. But it's too much to check all 12 lifters. So what it the chance that the one we check is going to be the one that shows wear? I doubt if all of them are worn.

[WLIU]

From the description, this is the first oil change after replacing the cylinder. Depending on how long the cylinder was off and the case was open to the dirty shop environment, and how sanitary the mechanic was when installing the cylinder, there was likely plenty of opportunity for "stuff" to get into the case. Most shops are not sterile clean rooms. Your note also suggests that neither the mechanic nor the tech support rep was excited about your particles. The issue that you are concerned about is a wear issue, not a sudden failure issue. So the best advice is to fly another 25 hours and look at the oil filter and screens again. If the cam is failing it will slowly wear down and your next examination will show more metal.

I know of a Bonanza owner who had a cam lobe wear almost entirely away. Engine ran fine until they opened it up for other reasons and saw the wear.

Or you could pull the starter drive to look for a problem in that area.

Best of luck,

Wes
N78PS

[Bill Greenwood]

Wes, my A&P is an very experienced on Beech particularly, and has been in business over 40 years. I asked and he said that the opening was of course covered while the cylinder was off, and it was short time thing, just a day or so as he keeps a replacement cylinder in stock.
This debris doesn't look like something that just fell in, doesnt' look like common dirt. I think it most likely is lifter material.
The Continental factory man said he could not really tell by the photos sent him on the internet.

I think I will send some flakes to Cont, but am planning on flying it for a few hours and checking again. I tend to be cautious by nature, but also because my normal flight is over the mountains. Most likely I am just delaying the day of paying anyway.

When and if I get the overhaul, I am strongly considering Ram in Waco. They are expensive, but seem to be good and I can easily fly the plane there and take the airline home, and I have friends in the area.

[WLIU]

The latest Sport Aviation has an article written just for you. Mike Busch has an article about Continental engines with cam problems. Nice photos and an explanation of the Continental service bulletin about how much cam pitting is allowable. Very interesting....

Best of luck,

Wes
N78PS

[Pearson]

Bill,

Your description of the particles sounded like bits of threads from a bolt, or a bolt hole. Did your mechanic mention anything about any striped threads? If so, I would keep flying and check the oil filter every few hours for more particles. Good luck! Let us know what you find when this mystery is solved.

[58boner]

I would not panic about small amounts of metal in the oil after engine work. Monitor. Shouldn't be any cam wear at 700 hours. These Continental engines have huge lifters and cam lobes compared to Lycomings. I'm in the middle of doing a top overhaul on my IO-470C9B in my J-35 Bonanza. 1400 Hrs. with not even cylinder work since factory reman in 1995. At 1400 Hrs the lifers are just starting to show about 10% coverage of the micro pitting and the cam lobes look new. I am replacing the lifters as a precaution.
It's not that hard to pull the lifters on that engine, but I would wait for more evidence. They will run great until there is substantial wear giving plenty of time to find a problem before a catastrophic failure.
It sounds like you are a very careful and prudent owner. Don't throw the baby out with the bath water. What you may have here is some break in trash or mechanic induced FOD.
I worked for Continental for a spell back in the 80's in their overhaul shop. These are really robust engines, you wouldn't believe some of the things I saw inside some of those engines!

[Sirota]

Bill,

WILU is on the right track. I'd call Mike Busch. I don't know what he charges if you don't subscribe to his service or even if you need to subscribe, he can proably tell you what to do and you can trust his advice. A hell of a lot cheaper then an overhaul.