What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Oil leak Titan 0-360

XLS+PAT

Active Member
It just started the other day. 30 minute flight and noticeable oil streak on the belly and around the right rear of the engine. Thought it was the oil filler tube since it was a bit loose. Tightened it up but no luck. Test flight had the same oil streak.
Pulled the top cowl and nothing jumps out as a culprit. Will pull the bottom cowl tomorrow.

Any ideas or recommendations?

Thanks

Pat


RV7 N931CB KHAF
 
Clean, run/fly, remove cowl, inspect; repeat as many time as necessary.
I assume you have already checked the easy things like lines, hose/fittings, etc. are tight.
 
Last edited:
Any ideas or recommendations?

Thanks

Pat


RV7 N931CB KHAF

No way you're going to find a leak source without pulling the bottom cowl. As Walt mentioned, Clean thouroughly, Take it for a good ride, Observe. Stubborn streaking can be identified with Talcum powder followed by a gentle shot from an air gun.

Larry
 
I think it was the most recent kitplanes magazine that outlined lycoming oil leaks. My guess is that you are seeing it from one of the same places.

I’ve been hunting leaks for a year now. I’ve begun to think that everything is leaking just a little.

Check the prop shaft seal, the oil filler neck, oil return hoses, oil drain plugs, filter, bypass hose, gasket around the cylinders, sump pan gasket, case halves on top of the engine etc....

Do not be afraid to spray the whole thing down with degreaser and then spray it off with a hose to get it clean. Make sure you dry it all good and then run it up and it should show you something.
 
Last edited:
Lycoming just returned my engine after replacing the leaking crankcase and front crankshaft seal. The new IO390 engine had 280 hours and was manufactured and installed in late 2018. I am installing the repaired engine this week hoping to never have another oil leak.

Look at the the lower crankcase with a flashlight towards the front crankshaft seal. Inspect the front crankshaft seal and the area below. If this is the leak you will also see oil on the front lower cowling.
 
I think I found the culprit. Screws on the valve covers were not tight. The engine has the old style gaskets. Ordered the silicone type from Spruce, they will be here Friday.

One of my RV guru friends thinks that should solve the leak mystery. Thanks for the tips from the VAF community.


Pat
 
One more easy thing

When the engine is warm/hot-ish, try and turn the push rod tubes. Not all stick but keeping them from free on both ends (usually expansion keeps one side loose) will keep those nuisance leaks away. Very easy prevention.
 
and using Loctite ...

U might already be aware... when using those, just tighten the screws according the instructions, i.e. lightly no more...

I just can second this that Dan wrote.

Also the star-washer is not in a good position to keep the screws from unwinding (not enough torque/pressure). A drop of Loctite 243 or better 248 (the "stick version") helps too.
Depends on the version of instructions, on some they mention Loctite too.

OR the GOLD-SOLUTION: SDS valve covers with O-Ring! I would go for this, if money is not an issue!
 
Last edited:
Well, finally got to test fly it and check if the oil leak problem was solved. After waiting over a week due to work and the local WX. IT'S STILL LEAKING.:confused:
Did two ten minute flights and each time I had oil on the belly especially on the right side where the cowl meets the firewall.

Since I'm out of ideas, I'll fly it up to Rio Vista and have the pro's at Team Light Aviation take a look at it.
 
Finally found the problem. The oil pressure line was the culprit. Only $18 from Vans for a new one. Easy swap out and now no leaks. What an ordeal.
 
Back
Top