Went to do my pre-flight, and a glob of orange-ish viscous material appeared in my fuel checker. It adheres like an oily substance. I had just fueled, let it sit for an hour, cleaned the tube, and I'm not seeing this anymore. Thoughts?
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Fuel Issue
- Thread starter jmiller007
- Start date
Avgas or autofuel?
I am running 100LL but it's possible the previous owner ran MOGAS. This plane did sit for a spell before purchase. When I checked the fuel before flying it home, there was nothing like this. Stopped for fuel in Morris, IL, then she sat for a week and then this result.
Mike S
Senior Curmudgeon
Can you catch a few gallons and filter through a very fine media to look for contamination?
Your photo in the first post shows a lot of something clinging to the barrel above the orange goo that just doesnt look right.
Both wings or only one side?
RV-12 with a central tank. The goo on the side is the same as the crap that first came out.
Do I need to drain the entire tank? Replace the fuel filter?
Mike S
Senior Curmudgeon
Cheap insurance if you do so.
As stated above, if you drain the tank, try to filter the fuel and see what you catch.
Yes and yes. This looks like it might be autofuel that has sat around for a while and stagnated, washed out by 100LL. It can turn to a lumpy mess and clog things up. Pull your quick drain and drain out ALL the fuel, either filtering it as it comes out or running it through a filter (even a paint filter) as you put it back in. In the old days they used a chamois. If this is in the tank, it might also be in your fuel filter. You probably don't want to find this out flying........... You might pull the fuel lines firewall forward and make sure they are clean, especially if there are low points in a fuel line bend. Not familiar enough with -12 to know where fuel lines go but flushing/draining from the most distal part of the fuel system would also make sense..........
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A few years ago, I had a similar thing occur (see attached pics). It would look exactly like your pic with the "goo" on the side just like what you have. The fuel came out of a communal 100LL fuel tank that somehow got contaminated. We finally figured out that it was some sort of microbe that grew in the fuel. There may have been some water or rust contamination that also contributed. This is known to happen in jet fuel but seldom in avgas but it can happen. Bottom line is that this stuff was able to pass through a fuel filter (that was also supposed to stop water) and my fine screen fuel filter and make its way into my carburetor. It would corrode metal (especially any steel) and finally caused my carb accelerator pump to stiffen and almost seize. It would pass through and then grow or somehow accumulate to a jelly like consistency. After we identified the source of the bad fuel we had a really hard time eliminating it from our aircraft tank. After doing a lot of sumping and draining and not seeing any more, we would still occasionally see the same thing. It was very persistent.
Finally my friend determined that the best way to fully eliminate it was to completely drain the tank and system again and then set up a small blower to continually blow air into and out of the tank to COMPLETELY dry out every nook and cranny. It seems like the drying finally killed the microbe where fine filtering didn't do it. After that (plus never using that supply tank again) I have not had any problems. If it were me, I would do what Roadjunkie1 said and drain everything and put that gas in your lawn mower.
Good luck
Keith
Finally my friend determined that the best way to fully eliminate it was to completely drain the tank and system again and then set up a small blower to continually blow air into and out of the tank to COMPLETELY dry out every nook and cranny. It seems like the drying finally killed the microbe where fine filtering didn't do it. After that (plus never using that supply tank again) I have not had any problems. If it were me, I would do what Roadjunkie1 said and drain everything and put that gas in your lawn mower.
Good luck
Keith
Attachments
rag
Active Member
I have to add to Keith's response:
Keith (Tailwind/RVGuy) and I have traveled (I have an RV4) across country together many times. At the time of this fiasco we both obtained our fuel from the fuel farm on our airfield. We encountered this contamination while in route to Montana. I tried isopropyl alcohol in my tanks, which did not make any improvement. We probably filled our tanks 3 - 4 times on the trip and the contamination persisted. After much investigation and discussions with the people at Biobor, who were a great help, fuel supplier people, who were no help, fuel tank service people, who were also of no help, we have arrived at a solution.
1. This contamination is a bacteria that likes rust and water. Its not common but does happen in the marine industry more so than the aviation industry
2. Rust and this bacteria will pass through any filter or filter screen. Over time it becomes coagulated - the orange jell.
3. It is not easy to remove.
4. In aircraft systems, the tanks and fuel system need to emptied and completely dried.
5. If you are using a in-line filter, Please check it! If you have a carb, pull the float bowel and check it. This stuff is corrosive
6. Change the source of fuel supply - I changed where I buy fuel.
7. Fill your tanks and add Biobor JF biocide (shock treatment amount)
8. Use a maintenance amount of Biobor JF for the next tank fill.
9. Even after all of this monkey motion, I still have had to treat my fuel tanks with Biobor on two more occasions.
10. This our experience - your results may vary.
If your fuel storage tank is contaminated - follow the same process, adding a thorough cleaning of the tank and make sure it is dry. Replace all filters. Shock treat the tank when you refill it.
I have a gallon glass jar that I test the fuel from the storage tank on a regular basis. The orange jell particles will appear on the sides of the glass just like you see on your sampler.
Again - this is our experience and solution. I would be very interested in your solution.
Had a Super Stol in the shop a few years ago, same contamination. As it sat for half a year, fuel samples came out with globs of it.
I pulled the tanks, thankfully removable, & sent them out to be steam flushed. I also found deposits all the way through the whole fuel system. All lines, valve, filters, electric & mechanical fuel pumps were replaced as well extensive carb overhauls. So check everything!
I also had a similar condition with a F-1. The owner actually had an emergency return to the field, engine lost power. I found globs all through his fuel system too. Ever re-plumb a Rocket? Not fun! He also had to replace pumps, gascolator, fuel servo, & spider.
I pulled the tanks, thankfully removable, & sent them out to be steam flushed. I also found deposits all the way through the whole fuel system. All lines, valve, filters, electric & mechanical fuel pumps were replaced as well extensive carb overhauls. So check everything!
I also had a similar condition with a F-1. The owner actually had an emergency return to the field, engine lost power. I found globs all through his fuel system too. Ever re-plumb a Rocket? Not fun! He also had to replace pumps, gascolator, fuel servo, & spider.
To add to what my friend and flying buddy Rick (rag) said above and what Ralph says on his post, this problem can exist even if you are flying on a regular basis so if you see any of that stuff then take the actions above. Fortunately it didn't cause me an off field landing but it did cost me a very expensive carb overhaul after I notice that my throttle control was really stiff. I blamed it on the cable until I figured out it was actually the accelerator pump causing the throttle arm to get so stiff I could barely move it with my hand. We found LOTS of that crud and corrosion inside the carb. It had made it through the inline fuel filter after the tank and also made it through the small carb filter (which showed no evidence on the little screen).
Good luck and please keep sumping those tanks. This issue has made me a believer about being diligent about sumping.
Keith
