Help! Metal in right wing tank

[JoeRuscito]

So I need some help thinking this through. About a week ago I sumped some metal from my right wing tank. Looked like metal filings (very small) and about enough to cover half the end of a pencil eraser. It’s not magnetic and looks like very shiny brass. I did not find it in the left tank and not in the header. I Stumped again and got very little more if anything.

Since then I’ve run the engine quite a bit. A couple flights in the pattern and balanced my prop. I did not find any more on any of those engine runs until yesterday. Same thing and amount came out of the right tank. This was just after refueling. I was suspect of the fuel but I have not found any in left tank and both were filled.

This time I may have found some in the header but I’m not sure if the cup was just contaminated from the right tank being sumped before.

any thoughts? I don’t know where this metal could be coming from. Thanks!

[bbs428]

Wow! If you flushed your tanks as recommended and I know you did, it has to be fuel contamination Joe. I mean how else can that metal get in there? My thoughts are that a fuel pump where you are refueling is starting to fail. Brass is common in fuel pumps. Why one tank and not the other? Who knows, really weird. :confused:
Fuel up elsewhere for a while and see if the contamination goes away. If it does you should notify the fbo. Just my 2c worth.

Fly safe!

[avidflyer]

Maybe you can refuel at the same pump, but run it through a Mister Funnel so it filters the fuel before it gets into the tank. Then you will maybe see the particles in the bottom of the funnel and know it's source for sure. JImChuk

[JoeRuscito]

I was and still am certainly suspect of the fuel and will talk with the fbo. Is there any chance it’s coming from the 912is fuel pumps? To your point Brett, that’s the only place that might have brass internally I’m not aware of.

[Dave S]

Joe,

Nasty deal....Jim Chuck's comment about using a filtering funnel of some sort should rule out or confirm the fuel source.

Curious, since I have a garden variety ULS and I could stand to learn a bit about the 912is - does the 912is pump fuel back to the wing tank? If so, does it discharge only to the one wing tank?

Have you had a chance to check the finger strainers in the fuel tank discharge - they are rather coarse, so I don't know if small brass particles would make it through?

[JoeRuscito]

The particles are way smaller than the finger strainers. And you are correct the return line from header only goes to right tank. In the case of the IS the fuel
pumps move way more fuel than the engine uses so you do tend to see more than just air return to the right tank. But that returning fuel would have gone through the 6 micron filter after the fuel pump assembly and prior to entering the engine/injectors after passing the injectors it goes through the fuel regulator and a check valve than back to the header.

[HighWing]

A thought. Do you routinely fuel the right tank first. If so, there might be a bit of residue that settles somewhere in the fuel pump system that only makes it into the first wing tank filled.

[JoeRuscito]

Great thought. I’ll keep that in mind but if I recall the left was first ok this last fill up.

[efwd]

Joe, I'm not sure if your having the same thing as I, But I have described particles much the same as you that I have found in my fuel samples. Mine is like translucent grains of sand. I posted here as well. I believe it was Ross who replied that he had the same stuff until he had about 100hrs on his plane. I just achieved 130hrs on mine and I might find a grain or two in at least one of the wing tanks each time I do a sample. I believe it is fiberglass from the tanks. I wouldn't describe mine as metallic like so I am not certain we have the same stuff. Something to consider. at ten hours I pulled the fuel filter and cut it open. I didn't find anything whatsoever in the fuel filter. You may recall one of my previous posts regarding fuel staining of the Oratex behind my fuel sample valve leak. This granular stuff is what lodged in the O-ring and caused the leak.

[GuppyWN]

Does your fuel return line go to the wing tank or header tank?

[JoeRuscito]

This stuff is definitely metallic, I also get a very little amount of the white sand like stuff once in a while but rarely.

The fuel system returns to the header. And then the header has a vent line to the right wing tank (where im finding this stuff). Again I don’t believe I’ve ever found this stuff in the header.

I pulled both of my filters yesterday. The course which is before the fuel pumps had a pea sized goo ball that was not stuck to the mesh (for sure extra thread sealant). There was no other debris in the coarse filter. I smeared the goo flat to make sure there wasn’t anything in it. I found some small specks of fiberglass and a couple pieces very small flakes of aluminum but nothing I feel concerned about and nothing that looks like what I’m sumping.

The fine filter was also clear. I found maybe four total flakes of stuff that looked similar to what I have in the right tank although bigger pieces by about 1.5-2x. Other than that the filter had some white flakes but very little and some other random flecs but again so few I’m not concerned. The filter had changed color from white to a greyish. I’m assuming that’s the lead in 100ll? I’ve been running 100ll with scavenger solely

Right now my best suspects are:

the check valve on the return line to the header. I believe that was brass and if it’s chattering when I’m only running one pump (lower fuel pressure) maybe that could cause flakes and maybe they aren’t settling in the header and getting pumped up the air vent?

The sump valve it self in the right wing chattering and causing local debris that never leaves the tank.

Something in the injector rails and or fuel regulator.

What do y’all think?





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[Shadowrider]

I would think its very unlikely the brass is coming from sump valve or check valve chattering......? Have you heard them chattering? That would be some serious vibrations to cause brass shavings to occur? One thing I was thinking though, is what type of fuel strainer are you using? Just wondering if its metal or plastic? If its metal I could see shavings form when your inserting the fuel strainer in and your scraping the side of the brass drain?

I think I would also try fuel from a different source, or pump fuel into a gas can, and then strain it into another fuel can so you can insure you are not chasing a problem that is not on your aircraft?

[JoeRuscito]

No I haven't heard chattering just an idea. Cant think of anything else. Im using a plastic stick fuel strainer. I didnt sump any today and I did get fuel from the same place. I had them show me the filters before fueling.

Im going to keep an eye on it, maybe it was bad fuel somewhere and its working its way out.

[jrevens]

Long shot, but the brass fittings on the tanks might be a possible source. If they weren't looked at very carefully before installing, it's possible that there were small shavings inside the bore. I've seen milling residue inside fittings adhering to the light oil film following machining during their manufacture. Sometimes fittings aren't cleaned as good as they should be. Like I said, it's a long shot.

[JoeRuscito]

Im still finding metal. The qty isn't really going up or down. Seems to increase after longer flight. I think Im going to add a line filter to the vent line and possibly the main line to see if I find anything. I just did an oil change and cut the filter, didn't see anything. Im wondering if its worth getting the oil tested? Is this common practice? Any suggestions?

[Shadowrider]

Joe I think I would try and narrow it down. Can you try getting fuel from a different source until your confident it’s not coming from the fuel. Are you doing the fueling? The fill neck on the tanks have a sharp edge the I can see would scrape metal off the fill nozzle. I use a vp gas can and if I let it touch the side it will scrape plastic off the fill nozzle. I could see it doing the same thing with the fuel nozzle If the angle is just right.

[JoeRuscito]

Hey Dustin. I have been fueling at the same place but I have asked them to show me the filters and they have. Also I think I would be seeing debris in both tanks. In addition, I agree the filler could scrape the nozzle, but the nozzle isn't copper/brass I dont believe.

[Shadowrider]

Yeah seems like it would be in both tanks. The IS has two fuel pumps that you alternate which one? Does running either pump and do you still get metal? If it’s not coming from the fuel in the tanks, then it’s got to be fuel system. Do you ever get medal out of the header tank?