Glen Davis Posted October 19, 2021 Report Posted October 19, 2021 So, I have a 1984 J. It’s relatively new to me. I have about 40 hours on it. Yesterday, I climbed to 12,000 feet. This was the first time I’ve had it above 8000 feet. While in the climb and climbing through about 10,000 both my wife and I smelled gas. The plane was at gross and the tanks were full when we departed, 64 gallons. The smell went away after about 10 minutes. I did not see any fuel leaking when I looked at the filler caps on the wings. Might this have something to do with the altitude? Any idea where to start investigating it so I don’t have a fuel smell/leak again? Thanks Quote
neilpilot Posted October 19, 2021 Report Posted October 19, 2021 Consider looking at each inboard level sensor gasket for staining. 1 Quote
toto Posted October 19, 2021 Report Posted October 19, 2021 This may be a totally irrelevant suggestion, but ... if you have a leaky compass, the compass fluid can smell gassy. And it sometimes only leaks at certain odd times. I had a head-scratcher smell for a while that turned out to be just that. 1 Quote
Yetti Posted October 19, 2021 Report Posted October 19, 2021 Pull lower side panels. Check your tank vents for obstructions. Pull the panel on the lower leading edge. Do a leak down test on mechanical fuel pump. Check under wings for blue staining. Check tank selector valve for leaks Quote
1980Mooney Posted October 20, 2021 Report Posted October 20, 2021 Similar topic from earlier this year if you had not seen… 1 Quote
carusoam Posted October 20, 2021 Report Posted October 20, 2021 Expect to find a top seem starting to get leaky… 1) If you haven’t filled the plane to the top before… this is the only time it leaks… 2) If it doesn’t leak in cruise… another sign that it is at the top of the tank… 3) there are drain holes under the wing… see if there are fuel stains left… 4) Opening inspection panels may help identify the source… use care not to open a panel in the tank… PP thoughts only, not a mechanic… Best regards, -a- Quote
Hank Posted October 20, 2021 Report Posted October 20, 2021 7 minutes ago, carusoam said: 4) Opening inspection panels may help identify the source… use care not to open a panel in the tank… This is why I put stainless screws in the panels I remove for annual, and leave the painted ones in the panels that don't come out. It's too easy to tell them apart, even when hot and sweaty and stooped under the wing. 1 Quote
carusoam Posted October 20, 2021 Report Posted October 20, 2021 Young mechanic experience… using powered screw driver… never saw him again… Serious fire danger… Best regards, -a- Quote
Matt M Posted October 22, 2021 Report Posted October 22, 2021 On 10/19/2021 at 10:11 PM, 1980Mooney said: Similar topic from earlier this year if you had not seen… On 10/19/2021 at 10:11 PM, 1980Mooney said: Similar topic from earlier this year if you had not seen… That was my post. Turns out it was the o-ring on the fuel cap and some play in one of the caps. When the tanks were topped the negative pressure over the wing was drawing fuel out. It vaporized and caused the smell. I could see a trace of blue aft of the one cap. Closer examination showed a bit of play. My mechanic put new o-rings on and tightened them up and problem has disappeared. 2 1 Quote
carusoam Posted October 23, 2021 Report Posted October 23, 2021 Great follow-up Matt! Thanks for sharing the details… Somebody around here is selling the blue fluorosilicone version of the fuel cap’s Orings… They have a much longer life than the usual orings…. Next time…. Best regards, -a- Quote
Mooney_Allegro Posted October 27, 2021 Report Posted October 27, 2021 Three years ago, while flying from Atlanta to Las Vegas, I refueled in Oklahoma with 100 gallons. After takeoff, I smelled fuel in the cabin. Instead of returning I continued (mistake). After landing in Las Vegas, I found blue stains under the fuselage, all over the nose gear bay, and all over the firewall and related areas (after cowling removal). It turned out the main fuel line on the fuel transducer was spraying fuel all over the engine right above the 1550'F turbos for 4 hours. The main fuel line at the firewall was not even finger tight, about to completely let loose. My mechanic advised me that it was by the grace of God that I didn't have an engine fire or failure. I was told that the fuel line should have been torqued at the factory, and it's not something that typically comes loose. It's not something that's normally checked at annual inspection, because it's wrapped up in fire sleeve material and difficult to access. I notified the FAA field office in Las Vegas and Oklahoma City and I think they found I was the second Mooney that this had happened to. I'm not sure of the other Mooney model aircraft. I ran up the engine the next day to locate the leak and it was eye opening the fuel being sprayed all over the firewall. I have video of the fuel spraying out. Richard Simile's new Mooney Acclaim (one serial number away from mine) crashed on approach into Lakeland years ago. He experienced power loss on approach. I wonder if he had the same issue I did with the fuel line coming loose. We'll never know for sure. Glen, I'd take the cowling off of your plane and look inside the engine bay for blue stains. I'd also do what others have mentioned above.... look behind the sidewalls in the cockpit. Sometimes the fuel leaks out from the many screws holding in the fuel lines. It's a pain to access, but I've seen leaks there in my previous 1998 J model a few months after a complete tank reseal. The screws were not tight enough, allowing fuel to leak into the cabin. 1 Quote
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