Rotax 914 leaking oil thru air filter

[Turbo_Boss]

Hello Guys,

Today I went to fly my Magni Gyro and to my surprise I see oil in the floor exactly under the turbo of the Rotax 914.

Its look like the oil is dripping from the hose that goes from the turbo to the airbox. Also the air filter is completely wet in oil.

I turn the prop by hand several times an the engine is not hydrolock. I also does not started the engine since I want to know whats going on before I started it again.

Last time I use it was like a month ago and everything was ok.

Last time I change oil, Rotax filter and plugs was like 20 hours ago and I have not add any more oil so it not that I overfilled.

Thanks for your help and advices,

Isaac

[wiskeyfoxtrot]

It could mean that the tubo seals have given in and you need to have the turbo serviced and the seals replaced.The seals keep the oil in the turbo to lube and cool the turbine shaft & turbo as a whole.Once these seals give in the oil leaks into the turbo and its what you have now.... oil all over the place.
Check if there is any oil coming out of the exhaust, thats a sure sign that the seals have given in.

Hope that you come right!

Later

P.S. get a reputable turbo repair centre to do the turbo,......cheap is K@K.

[MAGNIficent]

Did you see any other symptoms before the oil on the floor?

Your engine smoking?

Engine using excessive Oil?

It is important for us, other 914 owners, to check and learn from you.

[Turbo_Boss]

Check if there is any oil coming out of the exhaust, thats a sure sign that the seals have given in.

I will check is there is smoke coming from the exhaust. I will keep you guys informed of what I found

THX,

Isaac

[Morph]

for oil to leak out there would mean the turbo is full of oil and overflowing out the top?

is the oil not perhaps coming from the rectagular box next to it, the oil sump. I would look at that o-ring, 22 first

[Turbo_Boss]

Did you see any other symptoms before the oil on the floor?
Your engine smoking?
Engine using excessive Oil?
It is important for us, other 914 owners, to check and learn from you.

Last time I use it was like a month ago. There was not smoking and oil level was OK.

I also have a Aventura with a 912 and a Rans S-12 with a 912 too. When both of these airplanes sits for a longer period, the oil gets in the rear cylinders and the engine hydrolock. So I need to remove the rear lower plug and turn the prop by hand in order that the oil trap in that cylinder get out by the plug hole.

I really dont know if this was what happened in the Magni and the oil instead of getting inside a cylinder goes inside the turbo BUT this is the first time that happened. This 914 only have around 400hrs. I only use the turbo on take off only.

Isaac

[Turbo_Boss]

for oil to leak out there would mean the turbo is full of oil and overflowing out the top?
is the oil not perhaps coming from the rectagular box next to it, the oil sump. I would look at that o-ring, 22 first

Morph, thx for the pic. I am pretty sure the oil was coming from the hose that goes from the turbo to the air box, also the air filter was completely wet in oil.

I need to see when I have time again to go to my hangar I going to check it with a machanic and see what he find.

I will keep you guys updated.

THX,

Isaac

[MAGNIficent]

Can someone explain the oil "hydrolock" in the back cylinders?

Sounds like valve stemseals, but not sure.

[Morph]

Where is the oil tank installed. If above the motor, gravity will move all the oil into the motor. I guess the oil will then push into the pistons from below and leak past the rings.

Rotax have following warning in the installation manual

Warrning: At higher location of the oil tank, oil might trickle through clearances at bearings into the crankcase during longer periods of engine stop.

The tank is supposed to be installed around the midpoint of the motor, see pic.

[Morph]

Perhaps this is what happenend in this case

engine oil filled the rear pistons, pushed past the open intake valve and out of the carbs?

[MAGNIficent]

Found this in Maintenance Manual:

What might have happened:
The pressure valve (3) on the entry into the turbocharger housing prevents
flooding of the turbocharger (1) with engine oil by gravity after engine stop.

[Turbo_Boss]

Hello Guys,

On my Magni Gyro, the Oil Tank is installed under the engine so I dont think the problem was related to flooding by gravity. Please check the pic.

[Morph]

That's really strange. Which means that the oil is being pushed out the carbs while inder pressure, and the oil is only under pressure when the motor is running

let us know what the AP says.

[Stephan van Tonder]

It is not impossible that it is an oil seal failure on the turbo's intake side. The oil is under more pressure than the air and will get pushed out there if the seal has failed/is leaking. The fact that you are only using positive boost during take off means nothing. The turbo is not static during any other time. It is still happily spinning away at between 80 and 150 Thousand RPM

[MAGNIficent]

What was the final outcome of this PROBLEM?