914 aluminum shavings in oil filter 600 hours

Hello Jason,

The photo reveals a significant amount of material, which is an unusual finding that requires further investigation. Before we can provide additional information, it is essential to review the guidelines provided by Rotax in the Line Maintenance Manual (LMM) regarding such situations.

Please refer to LMM Section 12-20-00, subsection 13.5, titled "Inspection of the filter components," for the relevant information on pages 58 to 65. You can access the manual through the following link: https://www.rotax-owner.com/pdf/MML_914_Series_ED2_R2_E.pdf

In addition to the information provided in the Rotax Line Maintenance Manual, there are several questions and additional inspection requirements to consider, including (but not limited to) the following:

• Do you have an oil thermostat installed? If so, you should inspect the thermostat to ensure that the aluminum isn't originating from that source. Additionally, remove the oil pump and inspect it for wear, scoring, and any unusual features. This inspection should cover the bore where the spring and valve that control oil pressure are located, as well as the oil pump rotor and housing. It's also advisable to remove the oil return line and inspect the hole at the bottom of the crankcase using a bore scope to identify any unusual findings within the bottom of the crankcase. Furthermore, remove the oil tank and perform a thorough flush to inspect and eliminate any contamination.

• Remove the magnetic plug and inspect it for any unusual findings and excessive material buildup. It's vital to pinpoint the source of the material captured in the oil filter and understand the reasons behind it. It is advisable not to fly the aircraft until the causes have been determined. If you lack the necessary tools or experience to perform these tasks, it is recommended to contact your local Rotax service center for guidance and consider the possibility of sending the engine in for further examination.

To locate a Rotax Service Center and Repair Station near you, you can use the following link: https://dealerlocator.flyrotax.com/ 

Reach out if you have any further questions or need additional assistance.

Hello Jason

You said this engine has 600 hours.  How many hours on this filter?  Was the filter normal on the previous filter changes?  Until you can find the source please do not operate the engine.  

I would also recommend the use of a box cutter to take off the filter element.  The one you show looks like it was cut  with a rather rough knife end or torn off the filter can.  This only adds to some confusion.  In this case pull the oil tank and check the bottom of  it for debris.  With this much material you may find it is also contaminated. 

Cheers

The can of the filter was cut open with a filter cutter and was a clean cut. I used a hacksaw blade to cut the filter material not expecting to find anything. I took this filter off 25 hours ago and just got around to cutting it open. I will be removing and cutting open the filter that's on it now and I will be much more careful.  

In thinking about this how does the oil flow on these? Does it come from the tank directly to the oil pump through the filter and probably a bypass out to the engine internals? Is there a flow diagram?

Definitely won't be running it till I have identified and rectified the issue. 

Thank you 

J.

Jason...here is the description of the oil circuit from the heavy maintenance manual, section 79

SYSTEM DESCRIPTION

The engines are provided with a dry sump forced lubrication

system with a main oil pump and an integrated

pressure regulator.

Oil flow

The oil pump (driven by the camshaft) sucks the engine

oil from the oil tank through the oil cooler (optional)

and forces it through the oil filter up to the

points of lubrication in the engine and the turbocharger

(engine type 914 Series only). The escaping oil

emerging from the points of lubrication accumulates

on the bottom of crankcase and is forced back to the

oil tank by the piston blow-by gases. The ventilation

of the oil system is done by the vent fitting on the oil

tank.

Turbocharger (engine type 914 Series only)

The turbocharger is lubricated via a separate oil line

(from the main oil pump). The oil emerging from the

turbocharger is collected in a stainless steel oil sump

and sucked back to the secondary oil pump, from

there it will be pumped back to the main oil tank via

the oil line.

CRANKCASE

The engine oil emerging from the lubrication points

accumulates on the bottom of crankcase and is

forced back to the oil tank by the constant pressure

in the crankcase (blow-by gases).

In some older heavy maintenance manuals they used to have a flow diagram.  The description is accurate.  The question still stands on how did the filter look on past inspections?  If you use a box cutter blade when you removed the paper it will not leave any paper bits all over, just a lot easier to do it that way. 

Cheers

This engine is new to me. Its in an aircraft i flew from Florida after purchasing. I have since been to NC and back with it. Engine log books don't indicate any issues and I need to look at it again to see when the last note about the oil filter being cut open was.  The last oil and filter change was done around 550. This filter was removed at 600. I'll cut open the filter on it now tomorrow. I believe that one has 25 on it. I will definitely be pulling oil pump, tank and tracking the debris back to its source. 

I'm not an a&p but have 30+ years in high level automotive.  I also have an experienced a&p on the field that will be involved. 

Thank you for helping. I almost didn't cut it open. Won't make that mistake again in the future.  

J.