Thanks much for following up on this Steve.
Aztec Fuel Bladder Contamination
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Hi Pete,
Here’s the reply from my av fuels expert:
Have they been using mogas, or someone in the past? Sounds like the olefins from mogas polymerizing in the tank, as they are want to do, creating brown goo.
Avgas doesn’t have any olefins, for JUST this reason. 🙂
It could be bio-growth, but that would require dry tanks and a little bit of water… not impossible, but most folks don’t let bladders dry out.
I very much doubt it’s an avgas breakdown product.
I hope this helps you get to the bottom of this issue.
SteveThanks Steve. I’ve attached a photo of the left inboard before it was wiped clean, and an article about micro-organisms in your fuel. In thinking about this, I believe the problem started last fall…..after the Aztec sat for 6 months from April 2017 – September 2017 having both engines pulled for cams and lifters (275 hours since overhaul in 2012 by Signature Engines in Cincinnati), after 2 months of ownership. By December 2017 the fuel bowls were starting to show signs of contamination, and both fuel bowls were replaced at the annual inspection, which took place during that 6 month downtime.
Attachments:
finger screen left inboard bladder.jpeg
Micro-Organisms in your fuel.pdfHi Pete;
I have send an inquiry to a avfuels expert I know. As soon as I get an answer I’ll post it.
Does this brownish deposit feel like fine dust?
Is it possible that at some time in the past auto fuel with ethanol was put in this bladder.
I ask because ethanol holds water and mold and fungus can grow in water, but not in pure avgas.
If ethanol-auto fuel was put in that bladder fungus or mold could have grown in the tank.
I’m just jumping for an answer at this point.
I’ll let you know about the possibility of fuel causing a problem as soon as I know.Over the last 6 months, when I sump fuel out of my 1976 Aztec, I see white stringy stuff floating in the fuel. The fuel supplier at KDPA (Phillips) upon looking at a sample couldn’t explain what it was. I asked maintenance to investigate. Tanks were drained in order to access the bladders. The fuel cells were coated at the bottom with a brown sooty slime. Bladders were replaced in 2012. Maintenance contacted the fuel bladder supplier who stated that this could be a result of different fuel suppliers haven’t different fuel formulations, and the brown soot may be the result. The fuel filters were coated with this soot. Has anyone ever heard of this or experienced this?
I’ve attached a few photos, along with one photo of a special surprise in the left tank.
Pete N21NC !Attachments:
brown soot at bottom of fuel sample.jpg
rags with MEK used to wipe down bladders.jpg
surprise gift at bottom of left main bladder.jpg
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