O300D Aluminum in Oil

Well had my 1st oil change today. Have owned the 1964 172E for just 25
hours. When the filter was cut open we found a few small slivers of
Aluminum.

When I bought the plane the pre-buy inspection was a complete annual and the
mechanic didn't mention any "aluminum in the oil" so apparrantly this just
started.

What is the likely source of this aluminum? The mechanic suggested that I
fly for 10 hours and change the oil again to see if the problem goes away.

Anyone seen a situation where aluminum in the oil was a one time thing?

signed
"Not having a good day"

Gary Wilcox wrote:

When I bought the plane the pre-buy inspection was a complete annual and the
mechanic didn't mention any "aluminum in the oil" so apparrantly this just
started.

If the previous owner changed the oil and filter just before your pre-purchase, there
wouldn't be any particles in the filter for your A&P to find. Check the engine log
book. Assuming that an oil change was made and that the change was properly logged,
you'll know whether it just started or not.

What is the likely source of this aluminum?

Don't know that one. Most of the critical components such as bearings, cylinder
sleeves, wrist pins, etc. are not aluminum. I'd say that's encouraging. If I had to
guess, I'd say that a bearing is loose and eating away at it's housing, but that
usually makes a good deal of noise.

The mechanic suggested that I
fly for 10 hours and change the oil again to see if the problem goes away.

Stay close to home.

George Patterson
If a man gets into a fight 3,000 miles away from home, he *had* to have
been looking for it.

What is the likely source of this aluminum?

The O-540 in our Pathfinder was making metal at the pre-buy inspection. It
turned out to be aluminum from the piston pin plugs, and the amounts we
found convinced us to slash our purchase offer, and put in a new engine when
it was accepted.

(BTW: The new piston plugs are made of a harder alloy that won't spall,
supposedly.)

If you found a "few slivers" that's not abnormal. If there are a lot of
slivers, and you're flying a C-172 with the H2AD engine, you may have some
serious trouble brewing. (That engine was known for making metal, although
the latest oil additives supposedly have alleviated this problem.)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

How many years has it been since the engine was overhauled?

They hate sitting around.

Karl

"Gary Wilcox" wrote in message .. .

What is the likely source of this aluminum? The mechanic suggested that I
fly for 10 hours and change the oil again to see if the problem goes away.


Though I've never personally had that problem, I know a few that
have. In every case, the source of aluminum was the piston pin plugs.

John Galban=====N4BQ (PA28-180)

A possible guess based on experience from a C-150 which has the same
cylinders -
It could be a wrist pin end plug scrubbing the cylinder wall. This
was caused by a loose (i. e. floating) wrist pin rod bushing. A C-150
of ours always had produced a very small amount of aluminum which our
mechanic condemmed as having a lemon engine.

On teardown we found one wrist pin bushing loose in the rod end, &
that mechanical rectification was causing the wrist pin end to scrubb
slightly on the cylinder wall. I suspect the bushing had been cracked
loose during a previous disassembly.

We redid it with Millenium cylinders & a new rod of course. It has
been good ever since. It now is again at or beyond TBO.

On Tue, 2 Nov 2004 16:36:16 -0600, "Gary Wilcox"
wrote:

What is the likely source of this aluminum? The mechanic suggested that I
fly for 10 hours and change the oil again to see if the problem goes away.

Be careful about flying with visible metal in the filter. I had a
similar problem with my O360. Metal in the filter and I grounded the
airplane. My AP said nearly the same thing as yours, but suggested
that we look in the finger screen that is right before the oil pump
first. Pulled that and there were thumbnail sized pieces of Al in it.
So many large chunks that it was nearly plugged its whole length
(~4"). We started pulling jugs and found that the back bosses of one
piston (that provide support for the wrist pin) were nearly all broken
out! I hate to think what might have happened if I did fly a few more
hours....

My suggestion is to check the screen (not very hard to do) before you
fly.


Anyone seen a situation where aluminum in the oil was a one time thing?


Not very likely. The piston/wrist pin plugs are about all there is to
make Al.

Good Luck,
Jerry

Jerry Jesion wrote:


Be careful about flying with visible metal in the filter. I had a
similar problem with my O360. Metal in the filter and I grounded the
airplane.

I don't have a filter on my 470 just a screen. I only look at the
screen once a year, at the annual. A couple years ago I started to lose
the starter adapter. The shaft of the adapter shed some metal. We
found that in the screen at the next annual. No way I automatically
ground the plane because of a little metal. You have to find out what
it is and then figure out why it's there. Some metal it doesn't matter.

I don't have a filter on my 470 just a screen. I only look at the
screen once a year, at the annual. A couple years ago I started to lose
the starter adapter. The shaft of the adapter shed some metal. We
found that in the screen at the next annual. No way I automatically
ground the plane because of a little metal. You have to find out what
it is and then figure out why it's there. Some metal it doesn't matter.


I disagree. AFAIK particles of metal large enough to see with the
naked eye in the oil is not normal for any engine (with the possible
exception of just after a major overhaul). IMHO to fly with an engine
making metal is not a good idea. Especially if there is a constant
speed prop. First find out what is going on before making any
decision in this regard.

j

I have the same engine and had the same symptom. My mechanic changed oil and
said fly it 10 more hours and we will re-check. When we re-checked, it was
worse and it cost me $13,000 to get airworthy again. This was my second year
of ownership. :-(


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