flyingcheesehead Posted March 17, 2019 Report Share Posted March 17, 2019 Hi all, I own (with a partner) a 1997 Ovation. For the past few years, we've noticed an occasional fuel odor in the cabin in the winter. It didn't seem strong enough to be concerning, and it seemed to be limited to when the right tank was full, so we generally just tried to burn fuel from the right tank first after refueling. When we had it in for an avionics upgrade a bit over a year ago, I looked carefully at the right wing root and everything was pristine - No leaks, no sign that there had ever been any leaks (pics attached). Today, my partner noticed the fuel odor and found that it seemed to only happen when he was burning from the right tank *and* had the cabin heat on. Is there some location where fuel could possibly be leaking from only one side and having the odor sucked into the ventilation system? What else would cause this particular failure mode? I don't relish the thought of paying someone to pull the plane apart again and find nothing. Quote Link to comment Share on other sites More sharing options...
carusoam Posted March 17, 2019 Report Share Posted March 17, 2019 Fuel aromas are not normal or acceptable... Something is letting fuel out where it shouldn’t be... If you can smell it, it is leaving a blue stain somewhere... at least a light blue one... if it only happens with the right tank selected... get a pic of the fuel selector... top and bottom... otherwise, the fuel lines are always full, no matter which one is selected... Often fuel selector leaks, are combined with air leaks entering the fuel system... Air leaks into the system often show up in the FT101 data... higher than normal or unsteady numbers... Heat on can be a couple of different things... it can help evaporate fuel... And... heat blows across the fuel selector switch... if there is a leak there, Heat aided evaporation can be interesting... PP thoughts only, not a mechanic... Best regards, -a- 2 Quote Link to comment Share on other sites More sharing options...
flyingcheesehead Posted March 17, 2019 Author Report Share Posted March 17, 2019 Thanks - Good thoughts. Any idea as to why it would have manifested previously only when the right tank was full? What is "FT101 data"? Engine monitor? Unfortunately, we only have the Insight 602, which doesn't log anything. Quote Link to comment Share on other sites More sharing options...
carusoam Posted March 17, 2019 Report Share Posted March 17, 2019 FT101 is an older Fuel flow gauge.... in Os... Any FF gauge will suffer the same challenge if air bubbles are entering the system... Fuel tanks can develop leaks over years when exposed to heat... sun related heat... since the top is most susceptible to this challenge... a leak will happen first... when the tank gets filled to the top. Fill the tank to the top... and leave it that way for a while... When I first got my O... the access panels on top were all removed and re-sealed... plane lived in the south west, was hangered at night... Part of the PPI was to fill the tanks and let it sit.... Your pics are nice. Everything is so clean... opening a few access panels at the high end of the tank might be revealing..? There are a few fuel tank experts around the country... you might start considering some next steps... There is a good Mooney fuel tank guy up in cheesehead country, if you are still there... PP thoughts only, not a mechanic... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
MIm20c Posted March 17, 2019 Report Share Posted March 17, 2019 Fuel leaks can easily start well away from the wing root and leak (fumigate) back into the cabin. Normally this is evident when the plane is closed up for awhile. If it’s strong enough to smell during flight I’d have it looked at. Quote Link to comment Share on other sites More sharing options...
LANCECASPER Posted March 17, 2019 Report Share Posted March 17, 2019 On many Mooneys when the right tank when is completely full, one of the screws under the wing walk will leak. This link under "Panel Screws" explains how to repair. http://donmaxwell.com/fuel-tank-repairs-how-we-fix-them/ Quote Link to comment Share on other sites More sharing options...
Mooney_Allegro Posted March 17, 2019 Report Share Posted March 17, 2019 flyingcheesehead, Have you uncowled the engine area and looked thoroughly in the engine compartment/firewall area and checked all the fuel connections in the engine bay, nose wheel well, and under the plane for blue stains? I'm sure you have. Just a thought. Six months after my complete reseal (M20J) from the firm in MN, my wingwalk and left fuel sender screws behind the plastic trim sidewall started leaking badly. The cabin smelled like a refinery until I pulled the interior out and fixed it myself. I had to go to a local MSC for the wingwalk fix. Another instance in the Acclaim recently, the main fuel line loosened up and was spraying fuel all over the engine right above both red hot turbos. It was a blessing I didn't have a fire or failure. God was with me that day. Let us know what you find. Thx 2 Quote Link to comment Share on other sites More sharing options...
flyingcheesehead Posted March 17, 2019 Author Report Share Posted March 17, 2019 13 hours ago, carusoam said: FT101 is an older Fuel flow gauge.... in Os... 5 hours ago, LANCECASPER said: On many Mooneys when the right tank when is completely full, one of the screws under the wing walk will leak. This link under "Panel Screws" explains how to repair. http://donmaxwell.com/fuel-tank-repairs-how-we-fix-them/ OK, I don't have an FT101, I have a Shadin Miniflo. It's steady as a rock, so I don't think it's fluctuating, though I think it's smoothing over a fairly lengthy period of time - When I finish leaning, it might take a minute before the fuel flow stops changing. I have had a couple of the screws under the wing walk resealed and new wing walk put on, and we thought that was the solution, until yesterday. We're going to fly it together on Thursday and see what we come up with. The fuel selector is a fairly promising lead. 1 Quote Link to comment Share on other sites More sharing options...
flyingcheesehead Posted March 17, 2019 Author Report Share Posted March 17, 2019 11 minutes ago, Mooney_Allegro said: Have you uncowled the engine area and looked thoroughly in the engine compartment/firewall area and checked all the fuel connections in the engine bay, nose wheel well, and under the plane for blue stains? I'm sure you have. Just a thought. Six months after my complete reseal (M20J) from the firm in MN, my wingwalk and left fuel sender screws behind the plastic trim sidewall started leaking badly. The cabin smelled like a refinery until I pulled the interior out and fixed it myself. I had to go to a local MSC for the wingwalk fix. Another instance in the Acclaim recently, the main fuel line loosened up and was spraying fuel all over the engine right above both red hot turbos. It was a blessing I didn't have a fire or failure. God was with me that day. Yikes! The annual was very recent. I was only in the shop for one day of it and I didn't get a look at the belly pan, but the guys who work on the plane are meticulous and I can't believe that they would have missed any blue stains. We certainly don't have any on the hangar floor except where the tank sumps occasionally drip if they don't close back up just right... But now I'm going to have to clean that up and watch carefully. 1 Quote Link to comment Share on other sites More sharing options...
Mooney_Allegro Posted March 18, 2019 Report Share Posted March 18, 2019 When my plane comes out of MSC, that's when I find things that haven't been put back together correctly. I found 3 screwups this time after I uncowled the engine to look things over, and had to take the plane back. I hope you had a "no surprises" annual! Quote Link to comment Share on other sites More sharing options...
flyingcheesehead Posted April 2, 2019 Author Report Share Posted April 2, 2019 After some further troubleshooting, I found that the fuel return line from the engine-driven pump was leaking. Pulled it out today: I think it's probably leaking under where that Adel clamp is. The clamp was not really at the right angle for the travel of the hose, and it obviously chewed up at least the fire sleeve. Time to order a new fuel line and get that installed! 2 Quote Link to comment Share on other sites More sharing options...
carusoam Posted April 2, 2019 Report Share Posted April 2, 2019 Thanks for posting the pic, FCH! Are you able to cut the fire sleeve off and have a look under it to prove you got the issue identified? Or is there enough blue stain there to identify it? Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Guest Posted April 2, 2019 Report Share Posted April 2, 2019 That looks like it might be Stratoflex 156 hose, not their most durable type. Clarence Quote Link to comment Share on other sites More sharing options...
MIm20c Posted April 2, 2019 Report Share Posted April 2, 2019 Not to be an armchair mechanic but if the hoses are 22 years old you might want to replace all of them. Quote Link to comment Share on other sites More sharing options...
flyingcheesehead Posted April 2, 2019 Author Report Share Posted April 2, 2019 2 hours ago, carusoam said: Thanks for posting the pic, FCH! Are you able to cut the fire sleeve off and have a look under it to prove you got the issue identified? Or is there enough blue stain there to identify it? So, the full story is this: I flew with a friend to the nearest cheap-gas airport for some cheap gas last Friday. He had gotten there and fueled first, so he was watching me taxi up. When I shut down, a couple of drips came out onto the ground near the nose gear. We took a look as best we could with the cowl on, and found fuel dripping inside the nose wheel well. The next day, we pulled the top cowl. I primed it as if to start it, and we found this hose became all wet. There is visible damage near the adel clamp, and there are blue stains near where that adel clamp attaches to the airplane. We haven't yet cut off the fire sleeve, but we will... Plus there's the blue stain. 2 hours ago, M20Doc said: That looks like it might be Stratoflex 156 hose, not their most durable type. That's exactly what it is. Thinking about replacing with Teflon. Aeroquip AE466. Thoughts? 2 hours ago, MIm20c said: Not to be an armchair mechanic but if the hoses are 22 years old you might want to replace all of them. That was my first thought as well. However, I looked at the rest of the hoses in the engine compartment. None of them showed this kind of damage at all. And getting this one out drew blood. We're still on our original engine as well, and we have over 2,000 hours on it, so it likely won't be too long before we have to overhaul, and we'll definitely replace them all then. 1 Quote Link to comment Share on other sites More sharing options...
ArtVandelay Posted April 2, 2019 Report Share Posted April 2, 2019 I would and did replace all fluid hoses with teflon, and I have one the outer fire sleeve has been torn by rubbing against the cowl flap mechanism, which will be replaced this week or next.There are certain things if they fail can cause catastrophic damage, leaking fuel hoses are in this category.Tom 1 Quote Link to comment Share on other sites More sharing options...
Guest Posted April 2, 2019 Report Share Posted April 2, 2019 4 hours ago, flyingcheesehead said: So, the full story is this: I flew with a friend to the nearest cheap-gas airport for some cheap gas last Friday. He had gotten there and fueled first, so he was watching me taxi up. When I shut down, a couple of drips came out onto the ground near the nose gear. We took a look as best we could with the cowl on, and found fuel dripping inside the nose wheel well. The next day, we pulled the top cowl. I primed it as if to start it, and we found this hose became all wet. There is visible damage near the adel clamp, and there are blue stains near where that adel clamp attaches to the airplane. We haven't yet cut off the fire sleeve, but we will... Plus there's the blue stain. That's exactly what it is. Thinking about replacing with Teflon. Aeroquip AE466. Thoughts? That was my first thought as well. However, I looked at the rest of the hoses in the engine compartment. None of them showed this kind of damage at all. And getting this one out drew blood. We're still on our original engine as well, and we have over 2,000 hours on it, so it likely won't be too long before we have to overhaul, and we'll definitely replace them all then. Teflon type are a good choice, you’ve gotten good life from the current set. Clarence Quote Link to comment Share on other sites More sharing options...
MIm20c Posted April 2, 2019 Report Share Posted April 2, 2019 6 hours ago, flyingcheesehead said: That was my first thought as well. However, I looked at the rest of the hoses in the engine compartment. None of them showed this kind of damage at all. And getting this one out drew blood. We're still on our original engine as well, and we have over 2,000 hours on it, so it likely won't be too long before we have to overhaul, and we'll definitely replace them all then. That of course is your choice. But being in a partnership to share the burden and the fact that this is an owner maintenance item I would not think twice about it. Keep in mind you’re looking at the fire sleeve which has very little to do with the actual condition of the hose. Cut the sleeve off the hose you removed and flex the inner portion back and forth. If it’s stuff and or cracking the other ones will be the same. I would also closely look over the scat hose. You might have a damaged section that was pulling in the gas fumes from the engine compartment. We yanked our engine at 2500 hrs and I really wished we waited until 3k. Changing the hoses out at 15 years was a very good decision though. 1 Quote Link to comment Share on other sites More sharing options...
flyingcheesehead Posted April 2, 2019 Author Report Share Posted April 2, 2019 (edited) 3 hours ago, MIm20c said: That of course is your choice. But being in a partnership to share the burden and the fact that this is an owner maintenance item I would not think twice about it. Keep in mind you’re looking at the fire sleeve which has very little to do with the actual condition of the hose. Cut the sleeve off the hose you removed and flex the inner portion back and forth. If it’s stuff and or cracking the other ones will be the same. I would also closely look over the scat hose. You might have a damaged section that was pulling in the gas fumes from the engine compartment. We yanked our engine at 2500 hrs and I really wished we waited until 3k. Changing the hoses out at 15 years was a very good decision though. This one was hard enough to get out, I wouldn't really want to do them all myself. But, I probably still would if we were to do it right now. I will be cutting off the fire sleeve and if I'm appalled by the condition of the hose inside, I will definitely be doing all new ones. If it's OK, maybe not. Most parts of this airplane still look brand new. The scat hose from the muffler shroud to the air box with the heat control goes *right* past this leaky fuel line. Would not be surprised if fuel dripped on it. I doubt it'd soak through though, right? And I should probably see a stain if it did... I tried to remove it in the process of taking this fuel line out and even with the hose clamp completely off of that part of the tube, it would not budge from the air box. It does appear to be in really good condition on the outside at least. Edited April 2, 2019 by flyingcheesehead Quote Link to comment Share on other sites More sharing options...
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