Update - Fat Albert

I've got one that sounds just like yours on the left engine of our Aztec.
It drives me crazy. At our last annual, we thought it was a mag gasket, so
we changed the gasket, no luck. I've checked all the case bolts and they
are snug. Repeatedly cleaned the engine, flown it, re-checked, and simply
can't find it. Presently, I'm thinking it is an oil return line under the
#1 cylinder. There is a drop that tends to hang under it, but like yours,
it's hard to figure out where it's comeing from. I need to get a new hose
clamp on it, just to be sure, but it is almost impossible to reach without
removeing the entire bottom cowling.

Jim


"Jay Honeck" wrote in message
ups.com...
So, Sunday morning I got back to the airport, hung that remaining hose,
flew the plane (cool day) and so far no oil leak (jury still out at
this point)... But at least the engine compartment looks good with all
the scrubbing and the flashy new hoses..

Great story, Denny. Hope it works out for you.

I've had a minor oil drip for months, and it's been driving me NUTS.
Nothing seems to be leaking, everything is tight, yet after a couple of
flights the bottom of the engine is oily.

It's been impossible to locate the source, since the airflow just blows
it all over the friggin' place, evenly coating the underside of the
engine with an oily sheen. (At least we know we'll never have to worry
about corrosion...) Even though we all know that a little oil looks
like a LOT Of oil, it's still the kind of thing that bugs you when you
open the hangar door and find a drip on the floor.

The greybeards at the airport think I'm just stupidly anal ("Hell, if
ain't drippin', it ain't an airplane!") -- but I believe in finding the
root cause BEFORE it becomes a problem.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www. AlexisParkInn.com
"Your Aviation Destination"

Pulling the cowlings on Fat Albert is a 40 minute job for two men...
Replacing them is in the ball park of an hour plus... I have had the
cowlings completely off and back on 4 times in the past three weeks
chasing this leak... Getting pretty good at it, but not liking it any
better... This is on top of having the cowlings off the starboard
engine to change out the starter a week before we started on the
leak...

A month ago had you brought it up I would have been full of smug
instructions for chasing down the pesky leak, after 50+ years of
wrenching on engines... Since then I've had my hat size reduced...
This hose has been a real thrash to chase down because it appears it
only leaks when really good and hot, and then it mists oil thin as
water over it's entire length which blows around putting a uniform
coating of oil everywhere... (this is assuming I've finally done it -
still waiting on that hot day to get it warm enough to prove it is
fixed)

denny

Someday I'm going to seriously investigate the STC's that are out there for
split bottom cowlings. The ones I've seen put a doubler along the bottom, I
believe, just ahead of the air intake. You end up with a row of screws
running across the bottom cowl. Someday....

The oil leak we've got also mists over the bottom of the engine and onto the
rear accessory case. It's mostly noticeable due to the small puddle that
accumulates on the rear of the fuel injection throttle body where the air is
rather dead. Never enough to be measurable on the dip stick, it's just a
messy irritation.

Jim

"Denny" wrote in message
ups.com...
Pulling the cowlings on Fat Albert is a 40 minute job for two men...
Replacing them is in the ball park of an hour plus... I have had the
cowlings completely off and back on 4 times in the past three weeks
chasing this leak... Getting pretty good at it, but not liking it any
better... This is on top of having the cowlings off the starboard
engine to change out the starter a week before we started on the
leak...

A month ago had you brought it up I would have been full of smug
instructions for chasing down the pesky leak, after 50+ years of
wrenching on engines... Since then I've had my hat size reduced...
This hose has been a real thrash to chase down because it appears it
only leaks when really good and hot, and then it mists oil thin as
water over it's entire length which blows around putting a uniform
coating of oil everywhere... (this is assuming I've finally done it -
still waiting on that hot day to get it warm enough to prove it is
fixed)

denny

The oil leak we've got also mists over the bottom of the engine and onto the
rear accessory case. It's mostly noticeable due to the small puddle that
accumulates on the rear of the fuel injection throttle body where the air is
rather dead. Never enough to be measurable on the dip stick, it's just a
messy irritation.

That describes our leak as well. We've got grills that look like
"gills" on both aft sides of our bottom cowling, and a tiny trail of
oil will occasionally come out the lower right side "gill" -- never the
left. After sitting overnight, a drip will fall out of that area onto
the hangar floor, below that right gill.

Looking at the bottom of the engine, it's covered with a sheen of oil
-- but finding the source has been infuriating. There is no obvious
drip or puddle, and everything appears to be tight. Hell, it could be
running down from the TOP of the engine, hitting the 150 mph
slipstream, and atomizing all over the bottom -- only to gather back
into a droplet at the very bottom/lowest point.

It's never enough to register on the dipstick, but it sure makes a
mess. I'd love to find the source.

What makes it doubly aggravating is that we installed an air/oil
separator to eliminate oil on the bottom of the plane. (Which it did
quite well, until this leak developed...)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

What makes it doubly aggravating is that we installed an air/oil
separator to eliminate oil on the bottom of the plane. (Which it did
quite well, until this leak developed...)

I think Atlas is spiting you!
Jim

On 17 Oct 2005 12:12:06 -0700, "Jay Honeck"
wrote:

The oil leak we've got also mists over the bottom of the engine and onto the
rear accessory case. It's mostly noticeable due to the small puddle that
accumulates on the rear of the fuel injection throttle body where the air is
rather dead. Never enough to be measurable on the dip stick, it's just a
messy irritation.

That describes our leak as well. We've got grills that look like
"gills" on both aft sides of our bottom cowling, and a tiny trail of
oil will occasionally come out the lower right side "gill" -- never the
left. After sitting overnight, a drip will fall out of that area onto
the hangar floor, below that right gill.

Looking at the bottom of the engine, it's covered with a sheen of oil
-- but finding the source has been infuriating. There is no obvious
drip or puddle, and everything appears to be tight. Hell, it could be
running down from the TOP of the engine, hitting the 150 mph
slipstream, and atomizing all over the bottom -- only to gather back
into a droplet at the very bottom/lowest point.

It's never enough to register on the dipstick, but it sure makes a
mess. I'd love to find the source.

What makes it doubly aggravating is that we installed an air/oil
separator to eliminate oil on the bottom of the plane. (Which it did
quite well, until this leak developed...)

I found that spilling a teaspoon full when filling is good enough to
cover the entire bottom of the Deb.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com