FUEL SMELL IN COCKPIT--SOLVED!!!

[Brian Scranton]

Ever since I bought this plane back in February, I've noticed a smell of fuel in the cockpit (as I have report to y'all in the past) that would come and go, often when I would level off, lean and close the cowl flaps. I would also see blue stains on my right nose gear door and cowl flap. Nothing streaking down the belly. And, from the moment I purchased it, the fuel pressure gauge would always wobble between 17 and 20PSI without the boost, 23-25 with the boost. This weekend, I noticed my fuel pressure drop out of the green to about 13PSI so I turned on the boost pump and it stabilized.

I've been looking for a leak for months. My A&P has looked. His A&P looked. Other fellas looked. Hell, we looked quite a bit. We'd put the boost pump on and look everywhere for leaks...Thought maybe it was a small leak in the fuel servo but could never duplicate it on the ground. Thought maybe it was just that the boost would be dumping excess fuel overboard. Many of you guys suggested the sender, the tank witch, the pump itself...

Turns out...the fuel line going to the pressure gauge was resting up against an exhaust pipe...when we pulled it back we saw that it had charred all the way through... and when we turned the boost pump on it immediately saturated the braided hose and proceeded to soak the inside of the rubber housing! Faaaaaack. Glad I caught it, otherwise you guys would have been singing "Great Balls of Fire" at my funeral. 

 

[kmyfm20s]

Wow, glad you found it! 

[bradp]

Um that's about the scariest maintenance item I've seen on the board.  

[Guest Mike261]

Just now, bradp said:

Um that's about the scariest maintenance item I've seen on the board.  

I agree...that right there is bone chilling.

Mike

[1524J]

Wow....reminder to self....fuel smell in the cockpit requires immediate attention to resolve source!!! Glad you found the leak before it found the ignition source it was resting against.

[PTK]

Even more scary is that several sets of eyes looked at it and no one ever noticed a fuel line up against exhaust pipe! 

What were they looking at? How did they miss it?

[Piloto]

On any engine inspection it is important to look for chafing lines and wires against engine components. A spark plug wire resting on the engine or magneto will eventually break due to engine vibration and chafing. Chafing is a silent troublemaker that can cause an engine to quit. To avoid chafing use ty-wraps to keep the lines/wires from getting in contact with engine components

José

[Mooneymite]

Good job!  Your persistence probably saved your life and your plane.

We can all take away a lesson from your experience.  Thanks for sharing.

 

[Zwaustin]

Good catch, I would most likely be looking for another shop. Thanks for sharing this. 

[Bartman]

Ok so next time I have the cowl off I will check for this an othe lines and cables chafing agains something.

Very scary !!!

[Yetti]

Every time you have the cowl off or opened, look, touch, tug, trace each hose with your eyes from fitting to fitting.  Trace each wire.  Touch nuts and fasteners.  Touch spark plug caps for tightness.

[Brian Scranton]

Plus the annual at the previous owner's shop!!!! A pre buy. And multiple checks by at least 4 other pros. Crazy, right??? I can't believe how many eyes were on this. 

[Guest]

3 hours ago, PTK said:

Even more scary is that several sets of eyes looked at it and no one ever noticed a fuel line up against exhaust pipe! 

What were they looking at? How did they miss it?

They obviously weren't looking at this plane.

Clarence

[Guest]

4 hours ago, Brian Scranton said:

Ever since I bought this plane back in February, I've noticed a smell of fuel in the cockpit (as I have report to y'all in the past) that would come and go, often when I would level off, lean and close the cowl flaps. I would also see blue stains on my right nose gear door and cowl flap. Nothing streaking down the belly. And, from the moment I purchased it, the fuel pressure gauge would always wobble between 17 and 20PSI without the boost, 23-25 with the boost. This weekend, I noticed my fuel pressure drop out of the green to about 13PSI so I turned on the boost pump and it stabilized.

I've been looking for a leak for months. My A&P has looked. His A&P looked. Other fellas looked. Hell, we looked quite a bit. We'd put the boost pump on and look everywhere for leaks...Thought maybe it was a small leak in the fuel servo but could never duplicate it on the ground. Thought maybe it was just that the boost would be dumping excess fuel overboard. Many of you guys suggested the sender, the tank witch, the pump itself...

Turns out...the fuel line going to the pressure gauge was resting up against an exhaust pipe...when we pulled it back we saw that it had charred all the way through... and when we turned the boost pump on it immediately saturated the braided hose and proceeded to soak the inside of the rubber housing! Faaaaaack. Glad I caught it, otherwise you guys would have been singing "Great Balls of Fire" at my funeral. 

 

If I'm reading your profile correctly your plane is turbo normalized? If so then this AD likely applies, it calls for hose replacement every 5 years.

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/70CE05132A9BD8FE86256A390067A98A?OpenDocument&Highlight=81-19-04

Clarence 

[DXB]

4 hours ago, Brian Scranton said:

 

OMG, YIKES Brian!    Thanks for sharing, and glad you're still with us!!  

That is a horrifying picture. I may need to go the airport, un-cowl my plane, and trace all my fuel lines before I can get to sleep tonight!!

 

 

[N201MKTurbo]

It just goes to show you how robust those hoses are! After many hours of resting on a 1000 deg. plus exhaust pipe, it was hardly leaking. Any lesser hose would have burned or melted in half.

[Brian Scranton]

42 minutes ago, M20Doc said:

If I'm reading your profile correctly your plane is turbo normalized? If so then this AD likely applies, it calls for hose replacement every 5 years.

http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/70CE05132A9BD8FE86256A390067A98A?OpenDocument&Highlight=81-19-04

Clarence 

TRUTH. All the hoses are due to be changed this coming February. 

[testwest]

Thanks so much for posting the problem, the solution and the picture. That can really help someone else later, even to the extent of saving a life!

[jetdriven]

WOW !!!  Everyone check their hoses. The only thing they should touch is an ADEL clamp!

[ryoder]

Scary.  I flew with a fuel smell in the cockpit for months until I had the tanks stripped and resealed for $1000 each.  I should have don't it earlier.

[MyNameIsNobody]

So glad  this had a happy ending with the "found" hose on exhaust before as you stated "Great balls of fire"...

Do you have a shot/photo of the line in the plane?  Must of been difficult to see.  Was a clamp missing?  Did it come off?  Never on?  Removed and forgotten?  Unique hose position with Turbo install?

This is so great that you resolved this on the ground without incident.  Really happy for you and family/friends.  Pop a bottle of champagne and get toasted...YOU sir cheated death and it is indeed "Your Birthday" once again.

Happy Birthday to you

[Brian Scranton]

27 minutes ago, MyNameIsNobody said:

So glad  this had a happy ending with the "found" hose on exhaust before as you stated "Great balls of fire"...

Do you have a shot/photo of the line in the plane?  Must of been difficult to see.  Was a clamp missing?  Did it come off?  Never on?  Removed and forgotten?  Unique hose position with Turbo install?

This is so great that you resolved this on the ground without incident.  Really happy for you and family/friends.  Pop a bottle of champagne and get toasted...YOU sir cheated death and it is indeed "Your Birthday" once again.

Happy Birthday to you

I don't have a photo but it was on the right side of the engine compartment, coming down from the top of the fire wall, routed above the turbo, then making a left turn under cylinder #1, behind the exhaust pipe, right to the aft portion of the fuel servo. I'm sure at one point it was zip tied onto something to hold it away from the exhaust and over time it must have just snuck up on it. It was hard to see as it was behind the pipe and at a few different angles, looked like it had clearance Clarence. But alas...it did not. 

[bradp]

8 hours ago, Brian Scranton said:

I don't have a photo but it was on the right side of the engine compartment, coming down from the top of the fire wall, routed above the turbo, then making a left turn under cylinder #1, behind the exhaust pipe, right to the aft portion of the fuel servo. I'm sure at one point it was zip tied onto something to hold it away from the exhaust and over time it must have just snuck up on it. It was hard to see as it was behind the pipe and at a few different angles, looked like it had clearance Clarence. But alas...it did not. 

Clearly it could have benefited from M20Doc looking at it.... 

[MARZ]

That gave me the shudders - great persistence!  I've found that a super bright led flashlight helps a lot when poking around under the cowling - especially when in a hangar.