dirty oil leak but oil in engine is clean

Ive noticed a small oil leak where oil ends up coming down inside the nose leg fairing and then a small amount ends up on the nose wheel spat. This only happens after a flight and the oil is sooty / black. Whats odd is the oil has just been changed and when checking levels with the dipstick its clean.

When i changed the oil a few weeks back I couldn't see any obvious leaks.

Engine has 200 hours on it and all running parameters are fine.

Any ideas where this can be coming from?

Breather hose?

Oil deteriorates over time, it's lubrucation qulaities and its appearance change. Carbon and other minute particles get held in suspension and increased wear takes place hence we replace the 'spent' oil. If you have clean oil showing on the stick as it's just been replaced then any oil external of the engine should generally also be clean at first, what you have showing is probably been contaminated after it left the engine or is actually some of the older used engine oil than has now just showed up, not all oil remains in our aircraft engines due low tolerances etc. a legacy of yesteryear and very basic designs. By today's engine standards our old air cooled dinosaur engines are dirty by comparison to today's auto engines.
There's an old saying in the traditional 'round' engine community, if it ain't leaking something is wrong, it's out of oil!

Capt said:

Oil deteriorates over time, it's lubrucation qulaities and its appearance change. Carbon and other minute particles get held in suspension and increased wear takes place hence we replace the 'spent' oil. If you have clean oil showing on the stick as it's just been replaced then any oil external of the engine should generally also be clean at first, what you have showing is probably been contaminated after it left the engine or is actually some of the older used engine oil than has now just showed up, not all oil remains in our aircraft engines due low tolerances etc. a legacy of yesteryear and very basic designs. By today's engine standards our old air cooled dinosaur engines are dirty by comparison to today's auto engines.
There's an old saying in the traditional 'round' engine community, if it ain't leaking something is wrong, it's out of oil!

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I may get over it one day, but since my engine is not round, oil leaks are not accepted. At Continental the club planes were kept dry as a bone. Lycoming may be different.

The OP's leak could be a weep dripping on a moving part that adds some color to it. Look carefully. Any oil where a cowl touches will turn black quickly.

Mine does this too although very little. It's inevitable that there is going to be a little oil seepage or drips in the cowling. Airflow and pressures help move it around. Over the last six months I had noticed quite an increase of oil on the belly of my 7A. So during the annual condition inspection that I just completed this month, I changed out all the valve cover gaskets, one pushrod tube seal, the hose part of all the oil drain back lines and the main seal behind the prop. I also put a wrench on every nut and bolt on the oil pan part of the engine. I was surprised how much a few of them tightened up. My engine was brand new. I guess overtime they can get loose. I've got a few hours on it since doing all of this and it pretty much has taken care of all the excess oil. My IA mech expert said that you'd be surprised how much a few drips here and there will add up to quite a mess. My experience seems to have proved him right.

I've had this occasionally for 18 years and two engine builds. It is oil that seeps back down through the intake, and typically occurs after flights where the MAP is low compared to ambient (low power, local flight). Fuel from priming washes it down, and I believe the black comes from the K&N filter rubber degradation due to the fuel and/or oil. I have a hole on the rear bottom of the FAB, but inside the filter. This is where the black goo seeps out over the days following a flight. I have a small fitting bonded to the underside of this, and a small hose to dump it behind the cowl. I suspect the longer runs at low MAP suck some oil through the valve guides. I've wiped some of this oil out of the fuel servo and it is not black, so I do have some evidence that the dark color comes from the filter rubber.

It is very easy during an oil change to spill/drip some oil when removing the old filter with the drips ending up on top of the nose gear (tricycle). This oil will drain over time down the inside of the nose gear fairing and onto the nose wheel fairing. It can take many hours to all blow out. Matches the observed symptoms.

Oil Change Procedures

I'm sure there is a way to change the oil filter on my -8A/IO-360 without spilling some oil - but I haven't yet figured it out. I've spent a lot of $$ on "tools" that guarantee no oil spillage; none have proven 100% effective.

As Keith says, oil drips into the nose gear brace then slowly migrates down the gear leg, showing up as a black streak on the nose gear pant. Will continue for several flights depending upon the extent of the screw up.

I found a small leak on the nose wheel pant as you described. After doing what you did, checking every possible leak point, I found the quick drain was wet, not dripping. I poked a paper plug in the drain opening to see if it was the source. It seemed to do the trick. Might give it a try. Dan from Reno

If you drain just a little oil out of a quick drain and don't drain the entire sump when you close the quick drain oil will hangout in the fitting and it will drip seemingly forever and trick you into thinking you have a leak. I finally just sprayed a generous amount of denatured alcohol into the fitting to get the oil out.

Sniffle valve?