Rotax 912UL oil overflowing. Why?

Re: Rotax 912UL oil overflowing. Why?

by Arthur Götz » 12 years ago

Arthur Götz

6 31 1

Well, so many people can't be wrong. I thought to myself and started to trace the fuel supply. Result: It came from a diesel car that got wrongly filled with petrol. Thanks guys, you really helped.

Re: Rotax 912UL oil overflowing. Why?

by MARK JACKSON » 12 years ago

MARK JACKSON

12 332 11

Hi Arthur

I'm Glad your problem is sorted, just get rid of that contaminated oil now, it will wreck your engine.

Just one small point, when you gurgle the engine, it is air coming out of the return pipe after all the oil has been pushed out of the crankcase. It is not the return line being in the oil and blowing through the oil. The return line in the oil tank will be above the oil level in the tank.

Mark

Re: Rotax 912UL oil overflowing. Why?

by Arthur Götz » 12 years ago

Arthur Götz

6 31 1

Thank you, Mark, your explanation clears up a lot of misunderstandings I had about the gurgling question. Just one more question: What pushes the oil out of the engine when you gurgle, since there is no blow-by to do the job?

I replaced the oil, oil filter, fuel and fuel filter. I checked the pistons and sleeves as well as I could through the spark plug hole. Which wasn't really very good. There is a thin layer of deposits in the cylinders, but I looks like is coming off. The spark plugs look brand new. After 27 hours I would have expected them to look worse. The test flight was perfect, with everything, including my confidence in the engine, in the green.

Blue skies
Arthur

Re: Rotax 912UL oil overflowing. Why?

by Arthur Götz » 12 years ago

Arthur Götz

6 31 1

Thank you, Mark, your explanation clears up a lot of misunderstandings I had about the gurgling question. One more: If you gurgle you're emptying your oil suction side. Why would you want to do that? Surely the engine is lubricated quicker after start-up with the suction piping filled?

I replaced the oil, oil filter, fuel and fuel filter. I checked the pistons and sleeves as well as I could through the spark plug hole. Which wasn't really very good. There is a thin layer of deposits on the cylinders, but it looks like it is coming off, instead of being a result of the diesel. The spark plugs look brand new. After 27 hours I would have expected them to look worse. The test flight was perfect, with everything, including my confidence in the engine, in the green.

Blue skies
Arthur

Re: Rotax 912UL oil overflowing. Why?

by MARK JACKSON » 12 years ago

MARK JACKSON

12 332 11

Hi Arthur

No Problem, I'm glad you sorted it out, it sounds unlikely when you first hear what might be the problem. :-)

It is the blow by pressure that pressurises the crankcase. There is no crankcase breather, instead the pressure pushes the oil out through the bottom oil hose into the oil tank, then breathes through the oil tank breather.

I hope that clears it up a bit better.

Blue skies to you too

Mark