Typical areas for an oil leak?

KS Arrow Pilot

Filing Flight Plan
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Jun 9, 2011
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KS Arrow Pilot
My Arrow was recently "re-born" after my nose gear collapse. The engine was torn apart, each piece inspected, and re-built up in Poplar Grove. Not a complete overhaul, but close. My local mechanic in MO re-installed the engine and put everything back together. He flew it 2 hours, and then yesterday we both flew it about 45 minutes. Everything went great. Plane flew VERY well and after 5 months of no plane, I was elated to have it back again.

After the flight, I shut down the engine and went to push the plane back in the hangar. There were many splattering drops of oil coming out of the nose gear doors. After pushing the plane back in the hangar, I spent some time looking up into the doors and removed the top areas of the cowl to see where it was coming from. The mechanic couldn't tell either, and we decided he would need to completely remove the cowl to hunt for the leak. The dipstick showed almost no oil left in the engine... but it's mineral oil which is super clear and directly after a flight, it takes a while to drain back to the pan. It had 8 quarts to start the flight.

So I'm bummed. there is oil drenching most of the new components around the engine, and down the belly of the plane. The mechanic didn't have time to check it out until Monday, so I'm grounded another weekend.

I decided to post this ( to vent, and also) to ask other owners for common areas of a leak. The only one I know of is the dipstick guide tube, and it's on there very snuggly. Could I be looking at something major causing this? The area which has oil around it is near the bottom of the engine and all components. And yes, we were watching ALL engine gauges very closely throughout the flight and on the ground and everything was in the green.
 
Dipstick cap
dipstick tube
rocker box covers
oil pushrod tubes
front main seal
any accessory
oil sump gasket
oil drain valve
filter housing
oil cooler/lines
case seam
cracked components(!)
 
Dipstick guide tube, valve cover gasket, and the one that took me forever to get rid of was the "oil drain back tubes"
 
My Arrow was recently "re-born" after my nose gear collapse. The engine was torn apart, each piece inspected, and re-built up in Poplar Grove. Not a complete overhaul, but close. My local mechanic in MO re-installed the engine and put everything back together. He flew it 2 hours, and then yesterday we both flew it about 45 minutes. Everything went great. Plane flew VERY well and after 5 months of no plane, I was elated to have it back again.

After the flight, I shut down the engine and went to push the plane back in the hangar. There were many splattering drops of oil coming out of the nose gear doors. After pushing the plane back in the hangar, I spent some time looking up into the doors and removed the top areas of the cowl to see where it was coming from. The mechanic couldn't tell either, and we decided he would need to completely remove the cowl to hunt for the leak. The dipstick showed almost no oil left in the engine... but it's mineral oil which is super clear and directly after a flight, it takes a while to drain back to the pan. It had 8 quarts to start the flight.

So I'm bummed. there is oil drenching most of the new components around the engine, and down the belly of the plane. The mechanic didn't have time to check it out until Monday, so I'm grounded another weekend.

I decided to post this ( to vent, and also) to ask other owners for common areas of a leak. The only one I know of is the dipstick guide tube, and it's on there very snuggly. Could I be looking at something major causing this? The area which has oil around it is near the bottom of the engine and all components. And yes, we were watching ALL engine gauges very closely throughout the flight and on the ground and everything was in the green.

The leak could be anything, it's all been apart.

Wash it up, dry it, service the oil, and run it with the cowl off, 8 qts in 2 hours? it should show,

which engine, TSIO 360 or the Lycoming ?
 
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It's the Lyc B1E 180 horse. I don't think it's an engine gasket based on the volume of oil splattered over everything in just 45 minutes. It's not from the valve covers because those were easy to check. I'm just praying it's a "quick fix". I'll update this post after we find it, which will hopefully be Monday.
 
It's the Lyc B1E 180 horse. I don't think it's an engine gasket based on the volume of oil splattered over everything in just 45 minutes. It's not from the valve covers because those were easy to check. I'm just praying it's a "quick fix". I'll update this post after we find it, which will hopefully be Monday.

If I had to start the search, I'd start with a governor pad gasket. or a prop to crank seal (O-Ring) some body left some thing out.
 
Wouldn't it be nice if you de-cowled it, cleaned it up, ran it and it turned out to be a loose prop governor line?
 
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