182 few streaks of oil on the windshield

50kttailwind

50kttailwind

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50kttailwind
Flew 90min this morning. Nearing the destination, I noticed some spots and streaks on the window. Landed and verified it’s oil.

First check was prop and hub. All that looks clean and dry. Noticed a few more streaks on the cowl near the front. The oil cooler is wet in several areas. Any chance it could be that? Any other culprits to check?

The oil on the window looked clean and clear, which is odd. Our oil has enough hours on that it’s darker. Not sure that means anything.

Thanks!
 
The clean oil may be from a spill.

Assuming it’s an O-470 there are several possibilities for leakage.

The front mounted cooler is obvious as is the Governor.

The prop o-ring crank seal are also suspects.

“Wet in several areas” justifies further investigation.
 
That cooler or governor are suspect. The air comes in through the cooling inlets, but some of it is forced out behind the spinner where there's no ram pressure, and is blown back over the cowl. If there's any oil leaking around the front of the engine it will often get carried out with that air.
 
I had a light leak from the governor control shaft that produced very slight oil streaking on the windscreen. The control shaft was wet with oil when touched. Simple fix was an o-ring replacement. (182-S)
 
Dan is on-point that airflow behind the prop means it could be from anywhere upfront. That said, the most likely culprits are the plug at the bottom of the oil cooler and anywhere on the the front of the oil pan.
 
Jeff Oslick said:
Dan is on-point that airflow behind the prop means it could be from anywhere upfront. That said, the most likely culprits are the plug at the bottom of the oil cooler and anywhere on the the front of the oil pan.
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Oil cooler gasket, maybe.

upload_2023-2-25_18-49-23.png

or

upload_2023-2-25_18-50-34.png
 
50kttailwind said:
Flew 90min this morning. Nearing the destination, I noticed some spots and streaks on the window. Landed and verified it’s oil.

First check was prop and hub. All that looks clean and dry. Noticed a few more streaks on the cowl near the front. The oil cooler is wet in several areas. Any chance it could be that? Any other culprits to check?

The oil on the window looked clean and clear, which is odd. Our oil has enough hours on that it’s darker. Not sure that means anything.

Thanks!
Click to expand...
The gasket in the oil filler cap needs replacing periodically (gets compressed and doesn't seal as well as it should). However, that would seem unlikely to cause oil to be around the cooler. The cooler gasket could
cause the same sort of problem. Try tightening the screws. Note: I have seen a similar gasket leak in the fuel level sensors (especially when the weather is cold). Tightening the screws fixed it.

Dave
 
Thanks to everyone for your replies! 90% certain it’s the front crank seal.
 
If it's a Continental, there are split seals available for some. No prop removal necessary.
 
New to us 182G (belonged to a friend that passed away) - During the first fifteen hours or so of flying we had no oil leaks. Yesterday, we launched for a cross country flight with my son at the helm to deliver grandbaby supplies to our daughter in Colorado Springs. On our last stop of the day, I noticed a little oil on the windscreen and a small streak on the top left side of the cowling that looked like it flowed from under the cowling and moved aft over the top across tge oil filler door. There was also a single streak on the bottom of the cowl on that side.

Propeller hubs and main seal were dry, but today we flew from MKC to FLY in Colorado Springs and found new oil streaks on the leading edges of the props, but still no obvious leaks at the hubs. The right side of the case is dry. The left side is wet.

I suspecting a bad filler cap seal, filler base seal, or breather issue. We'll have to pull the cowling tomorrow to do a proper search. Hoping I don't need to find an mobile A&P in the area.
 
Bluejet said:
...Propeller hubs and main seal were dry, but today we flew from MKC to FLY in Colorado Springs and found new oil streaks on the leading edges of the props, but still no obvious leaks at the hubs. The right side of the case is dry. The left side is wet. ...
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You didn't pull the cowling immediately?
 
First off, check it and see if it's really grease and not engine oil. A lot of dumbass mechanics don't read the instructions. You don't just stick a grease gun to the zerks on the hartzell prop and pump it in.
 
50kttailwind said:
Thanks to everyone for your replies! 90% certain it’s the front crank seal.
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I was quite sure as well, but it turned out to be the HOBBS meter pressure switch, which I learned after removing the prop.
 
Domenick, No. I don't pull the cowling immediately for a little oil streak. Do you? I'll post a photo as soon as I have enough posts as a newly-joined member of this group.

After 45 years of flying, I've learned to not panic when a little trickle of oil shows up. Cleaning it up and looking for the source today.
 
50kttailwind said:
Thanks to everyone for your replies! 90% certain it’s the front crank seal.
Click to expand...
I was quite sure as well, but it turned out to be the HOBBS meter pressure switch, which I learned after removing the prop.

I wonder if the OP is still around to fill us in on what the leak was from over 3 years ago?
 
Domenick said:
You didn't pull the cowling immediately?
Click to expand...

This. Pull cowl and spinner, see where it comes from.

Keeping engine clean helps greatly when trouble shooting. Washing down the engine compartment with mineral spirits at each oil change is time well spent.
 
Bluejet said:
Domenick, No. I don't pull the cowling immediately for a little oil streak. Do you? I'll post a photo as soon as I have enough posts as a newly-joined member of this group.

After 45 years of flying, I've learned to not panic when a little trickle of oil shows up. Cleaning it up and looking for the source today.
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Yes. I would have. I have. Found the oil temp sending unit had captured the safety wire underneath and the engine was hemorrhaging.
I sure as hell would not be flying a passenger with an undiagnosed oil leak.

I've prophylactically pulled the cowling for other reasons. Once, after a flight, something just felt off. Pulled the cowling and found the carb float bowl loose.

After 25 years of flying, I've learned there are no little warning signs.
What other warning signs do you routinely ignore?
 
Captain John Sullivan likes how you think. (The High and the Mighty.)

Oil breather was completely gunked up with thick, black sludge. Who knows how long it has been building up?

No major crisis and oil weep is gone.
 
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