Fuel smell in cockpit

[Paul Allen]

I have a 1981 Mooney 201 and I think I'm smelling fuel inside after the plane has been closed up. Any ideas what to look for? I don't see any fuel leaks.
Thanks

 

[Brian Austin]

I have a 1981 Mooney 201 and I think I'm smelling fuel inside after the plane has been closed up. Any ideas what to look for? I don't see any fuel leaks.
Thanks

I had this problem in my truck. Turns out I tracked diesel on my boots, then transferred it to the carpet a few days before.

I'm not saying you shouldn't get it checked but it doesn't necessarily have to be with the fuel system itself.

 

[Iceman]

I have a 1981 Mooney 201 and I think I'm smelling fuel inside after the plane has been closed up. Any ideas what to look for? I don't see any fuel leaks.
Thanks

If I were you I would open up the plane and let it air out. Then start smelling around (up close and personal) everything like seats etc until you find the place the smell is coming from...go from there. Brian might be right that it is just something that was tracked in. However, 100LL is different than diesel in that the smell does not "track" as easily.

 

[bbchien]

If I were you I would open up the plane and let it air out. Then start smelling around (up close and personal) everything like seats etc until you find the place the smell is coming from...go from there. Brian might be right that it is just something that was tracked in. However, 100LL is different than diesel in that the smell does not "track" as easily.

I had a Monroy equipped M20J, N201 MZ. It had tank problems. You don't see the stains because the fuel runs INSIDE the skins inboard of the wheel wells (station 48) and into the overlapped skins into the belly of the A/C.

I did multiple spot seals but the sealant was just too old. Charlie Hinojosa resealed it at FXE - a $10,000 job when it was all over. But it was tight. Charlie's gone now....

 

[Paul Allen]

I'll check and see if it was something tracked in. I'm smelling this as the plane is just fnishing it's annual, so I suppose the fuel smell could be from someones boots. I was not sure if there was something with the Mooney.
Thanks

 

[Ed Guthrie]

I have a 1981 Mooney 201 and I think I'm smelling fuel inside after the plane has been closed up. Any ideas what to look for? I don't see any fuel leaks.
Thanks

Much as others have suggested the footprint theory, I seriously doubt it with 100LL. In a 1981 Mooney M20J it could be four possible sources. First is the fuel level senders in the wing roots, behind the side panels. Second is the fuel tank selector on the pilot side floor (or center floor, not sure when it moved). The center shaft seal on those will eventually fail. Third is the fuel pressure feed line behind the panel, leading to the fuel pressure gauge (might be electric on later models, but early 201's were fuel line fed). Fourth, and this is the one you don't want to have but probably is the culprit--fuel tank leaks. A leak could be anywhere and you will still get fumes in the cockpit. For example, even if the leak is at the upper seam of the most outboard wing rib the fuel will often run along the spar/wing skin seam, eventually finding its way into the cockpit (the spar passes through the cockpit behind the rear seat kick panel). One way to seek out the leak entry point is to lay white terry shop towels (buy a bulk package at Wally World or Pep Boys) along and touching the cockpit floor/side wall seams and rear seat kick panel/floor seam. Leave the towels for a day or two and you will probably find a blue stain on one of the towels.

 

[Stache]

There are a couple places to look. First place the the primer. Over the years pushing and pulling on the primer will wear the shaft and it will leak around the o-ring. The only fix is to replace it.

Second is rubber fuel hoses that are old and cracked. If your rubber fuel hoses have not been changed in the last 10 years or so they will have small cracks in them.

Stache

 

[SkyHog]

In a rental, I noticed this - it turns out that the fuel strainer I was using smelled very strongly, and we keep them in the seat pocket.

Hoping it's that easy for you.

 

[Dave Siciliano]

I know this sounds funny, but if all else look good, check your mag compass. I had the fluid slowly run out of mine and smelled it for several days before I figured out what it was. It's a little difference smell than 100LL, but still smells like kerosene. Had me going until I finally noticed the fluid level slightly down. Happened when the plane came back from the shop; so, I was asking what they had done until I figured it out.

Best,

Dave

 

[Len Lanetti]

Paul,

Ed is spot on. Feel free to check the suggestions made in all the posts but you should be prepared for either a full reseal of the tanks or installation of O&N bladders as the worst case scenario.

There are pros and cons on getting bladders vs reseal (if this is what you require). I went with the bladders for my M20C. I got a few extra gallons of useful fuel load, the trade off was that the bladders increase empty weight. The amount of fuel available with the bladder and the increase in empty weight vary by model.

I don't know where Massillon Ohio is but the O&N shop is located just north of Scranton PA (which is north of Philadelphia)...airport is Seamans 9N3.

Here is their website.

http://www.onaircraft.com/

Len

 

[pete177]

I've got some pretty good leaks to include the senders behind the side panels. Once they were resealed the fuel in the cockpit smell went away but there still leaks in the tanks.