182 few streaks of oil on the windshield

5

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.
Click to expand...
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.
 
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