mattbucy

My dad trained in the army but quit after getting into mountain wave in a 150 where he got pushed down to within a couple hundred feet of a mountainside. As a kid, I found his sectionals, logbook, etc and became fascinated, planned imaginary flights, learned how to use his E6B, occasionally saved up the $20 required back then for a discovery flight. Thirty years later, I ended up right seat in a de Havilland Beaver floatplane in Alaska and knew as soon as we took off I wanted to get a license. I signed up at a flight school in New Hampshire, got a few lessons in, and the school closed. Knowing I was successful at my business, the owner propositioned me to take over the flight school. Thinking I might be able to get lessons and flight time nearly free, but also fully aware I might be foolishly tossing money out the window (good practice for owing an aircraft) I went for it. And indeed, I tossed a fair amount of money out the window and closed the school, which was a miserable failure. But, I got my license and eventually started a flying club from the remains of the school. I bought my Mooney in the period between closing the school and starting the club, thinking I would have no plane to fly. Little did I know the club would grow and thrive. But, I'm still glad I've got the Mooney.

Might be a long shot, but I had a similar problem not long ago. Pulling the 430 out and reseating it solved the problem. Mine might have been a little loose after panel work.

@carusoam Thanks Yeah, I'm mostly a lurker haha.

@alextstone Aircraft has run fine since, no issues, thanks. No leaks either. And, yes, thankfully, insurance did its job. Good luck with your reseal!

@alextstone We did test my fuel and none showed dissolved PR-1005L. It was never conclusively determined what caused my engine incident, but fuel contamination from dissolved PR-1005L sealant was ruled out. The only reason we suspected PR-1005L was that PPG told us it might dissolve, which was pretty shocking to hear. I did a few tests myself with it. Ethanol definitely softens it. But, 100LL doesn't seem to affect it. The rep at PPG also told me that PR-1005L is not necessary due to improvements in primary sealants but Mooney will not remove it from the manual. PR-1005L was developed 70 years ago for the Lockheed Constellation to fix its leaky tanks. Perhaps Mooney thought, oh this will solve our leaky tanks too.

In my case, the fuel has become contaminated twice, first at the airport where I had tank work done and now a second time, two months later, with fuel from four different FBOs. I'd be astonished if four FBOs had laced fuel. Perhaps once compromised, it's toast and continues to leach.

Nels, we may. Good idea. But, we're looking to the contaminant itself first since we want to know where this stuff came from.

Nels, We described our situation and they said they've recently had roughly a report a month, mostly from Mooney owners, who are seeing problems with this top sealant. Their guess is that the fuel may have had alcohol in it, that distributors have been known to cut 100LL with small amounts of ethanol. They said just a small amount of ethanol will compromise the sealant. But, I think that's just a guess. Like I said, in my case we are not certain this sealant is the culprit. But, I relay this information because it came from PPG and seemed important to get out there. In a few weeks, once my engine is torn down, and we can test the contaminant, we ought to have a better idea. PPG gave us specific things to look for in the contaminant that would be signatures of the sealant. -Matt

I posted this to the MAPA list and am cross posting here because it may turn out to be important. Long story short, I've been dealing with an engine contamination event after a tank reseal that caused a mid-flight shutdown of a 57-hour old engine and coated the cylinder interiors with a black, gunky substance. I, with my insurance company and mechanics, have explored all kinds of theories as to what happened. We've had lab tests made of the fuel (negative for Jet A) and will soon have results from testing of the black, gunky substance once the engine is opened up. FYI, all fuel filters were 100% clean. The new tank sealant is holding fine. Compressions on all cylinders cold is in the 70s. Engine monitor data suggests fouled plugs caused the shutdown. The shutdown was brief, the engine ran roughly for about three minutes, then cleared itself and ran normally until landing, after which the interior contamination was discovered and the plane grounded. Two days ago, on a lark, I opened up one of the plane's fuel tanks to check the fuel. It's tanks are full and they have sat undisturbed for two months as we've puzzled. The fuel smelled horrible and looked strange, stringy. This suggested to me something was leaching into the fuel from the tank sealant. What else could it be? My mechanic made a call to PPG, the manufacturer of the sealants used on my reseal. They informed him that while the main sealant used, PR-1422, is insoluble in fuel, they have had reports recently of the recommended protective top coat sealant PR-1005-L dissolving in 100LL. They no longer recommend its use. However, it is specified by Mooney's tank sealing manual, which I expect is the bible for lots of shops. The PPG rep described to a tee what the inside of my engine would look like if PR-1005-L was run through it: a black, tarry gunk throughout. Bingo. Apparently, some 100LL will dissolve it completely such that it flows right into the engine with the fuel and is not caught by fuel filters. I'm posting this hopefully not to needlessly alarm, but to inform the Mooney community that there seems to a problem with this sealant, according to its manufacturer. I'm not sure why they haven't made a statement to this effect. They did tell us emphatically not to use it and to strip any remnants of it from my tanks before running an engine on the tanks. While I cannot be certain yet that this sealant is the culprit in my engine troubles, it is so far the only candidate that makes sense. In 2009, the NTSB investigated an accident that specifically implicated this sealant. Vans has issued a SB that this kind of sealant is not to be used. PPG says they have advised Mooney but, as far as I know, no SB has been issued. PPG says most of the cases reported to them are Mooneys, probably because Mooneys have more tank work and reseals than other GA planes and the Mooney manual specifies this top coat for reseals and repairs. If I understand the history, PR-1005-L was designed long ago for pre-100LL fuels which were formulated differently. The last application bulletin for it was written in 1972! I advised my tank reseal shop and they're looking into it. In a nutshell, if your fuel smells and looks fine, I doubt you have a problem. However, if you have had recent tank work in which PR-1005-L was applied, I would keep a close eye on your fuel, especially if your plane sits for longer periods where fuel could work on the sealant. If you ever notice your fuel looks sort of stringy when agitated in your sumping container or smells like rotten rubber, I would not fly. You may also be able to visually determine if you've got this sealant in your tanks. PR-1005-L is clear but red in color and appears as a red tint over the darker main sealant. Other manufacturers may also tint their top coats, but if you know you've got PPG sealants, the red would be PR-1005-L. Here's a link to video I made of 100LL contaminated with a bit of Jet A. We determined Jet A was probably not implicated in my case, but my contaminated fuel looks a lot like this. -Matt

Thanks for the input, everyone. Glad to know the pitting isn't unusual. She runs smoothly and with plenty of power but since she's new to me I'm curious. I started using CamGuard a couple months ago. I figure it'll at least arrest further corrosion. Cujet: nice job on that cylinder. Wish mine looked so pretty!

Mike: good idea. Matt: good to know. Thx. Sent from my iPhone using Tapatalk

Matt, did you replace the engine eventually? What triggered it? Sent from my iPhone using Tapatalk

I've got one of those coming up next month! Sent from my iPhone using Tapatalk

My mechanic got back to me. Says just watch the oil for signs of wear and fly it! Nothing else warranted despite age. With all the pitting he says the oil consumption is to be expected. Makes sense. A lot of oil is being left in the pits each stroke. I would be tempted to pull a jug to see what's up with the cam but yeah it's invasive. I've always been someone who loves to take things apart. Wish there were some way to take a peek that didn't require surgery. Sent from my iPhone using Tapatalk

Thanks for comments. I used a SnapOn BK8000 borescope. It's got two integral cameras and lights on a flexible probe, one camera off the end of the probe and the other 90-degrees. It requires getting close to things to see well, so yes, the pix are extreme close ups. Valves look fine, symmetrical deposits and coloration. Stems are a bit gunky. Seats are clean and mostly shiny with some mild corrosion. Oil filter is always clean and oil analysis shows nothing unusual over three years of samples. It produces plenty of power. It drinks a fair amount of oil, 4-5 hrs/qt. Compressions are above 70. My A&P is looking at pix too. I'll let you know what he says. Sent from my iPhone using Tapatalk