Diesel Smell

[wojo5901]

Hello All,
I put in100 gallons of diesel about 1 month ago for winter storage. I am on the Cheasepeake bay. Went down to winterize the boat this past Sunday. Boy did the inside of the boat smell of diesel. I did not see any diesel on the bilge, so I feel that there is no leak in the fuel tanks. Does anyone know of a filter on the fuel vent pipe? or have any other suggestions? The boat will be pulled within the next week or two.
Thanks,
Mark

 

[CharlieO.]

When I replaced my fuel tanks I knew one had a small leak but the other one was completely rusted out at the top around the fill pipe. Just because there is no fuel in bilge it doesn't necessarily mean a tank is not compromised. Hopefully it is something minor. Good luck!

 

[tiltrider1]

A very small amount of diesel can make a very large smell. Diesel can also be absorbed by wood work that makes it hard to find the leak while allowing the odor to permeate the boat.

My trick is lay down a lot of oil absorption pads around the tank.

 

[Ertyqway]

If you can smell diesel, you have a fuel leak somewhere. If it's intermittent, it's probably small and is only leaking when the fuel system is pressurized. We had a supply fitting go bad on our generator about a year ago and started smelling diesel whenever the engines or genny were running, but also when they were off and the diesel heater was on. Any one of those three things would pressurize the fuel supply lines and cause a small drip leak inside the generator cabinet.

 

[Bmarler]

has this ever happened before? have you filled the tank to this level before? can you see the top of the tank and the fill and vent hose connections? can you see all sides of the tank?
there must be fuel somewhere. you just haven't found it yet.

 

[High Wire]

It could be the fill hose, the vent hose, the lines to and from the engine, the top of the tank rusted or the bottom welded seams or the engine itself. If you smell it there is a leak somewhere! The good news is the leak will be red fluid.

 

[Bacchus]

If a new problem that became apparent after filling I'd be looking at any / possibilities high on the tank and in the vent/ fill system.
Thorough inspection & cleaning & airing out... to see if us a recurring or 1 time issue.

 

[Comodave]

I agree, if you are smelling diesel you have a leak. You just haven’t seen it yet. Place diapers everywhere and then look for stains.

 

[BruceK]

Does there need to be a leak? Say the deck filler pipe to the tank is rusted/ fractured, or the tank has rust openings on top, that could be enough to release fumes into the boat.

 

[tiltrider1]

Does there need to be a leak? Say the deck filler pipe to the tank is rusted/ fractured, or the tank has rust openings on top, that could be enough to release fumes into the boat.

You could be right but odds are that it is a very small leak that is evaporating. Does not hurt to look for other causes but I would do it after I spread a lot of absorbent pads around.

 

[Bmarler]

Does there need to be a leak? Say the deck filler pipe to the tank is rusted/ fractured, or the tank has rust openings on top, that could be enough to release fumes into the boat.

Both of those scenarios describe a leak. Fuel doesn’t need to be actively seeping out for you to consider it a leak.

 

[Shrew]

Diesel is lighter than water. If there is water in your tank, it will be at the bottom. The bottom is where tank leaks most frequently occur in older boats.

You likely have seeping from the bottom of the tank that is pooling very slightly UNDER the tank and not visible until you pull the tank.

As stated, if you smell fuel, you have a fuel leak.

Did you overfill the tanks and get expansion in warm weather? That will start purging out the vent and run down the sides of the boat. If the boat is shrink wrapped, then vapor and get inside of the shrinkwrap.

 

[sunchaser]

Older "decrepit" diesel fill hoses can smell with no sign of leakage. Plus it is not unusual for budget builders to use cheap non diesel compliant hoses in this application, particularly if the same model boat was offered with gas engines a few decades ago. I'd this problem with a mid nineties gas Sea Ray where the fill hose was non-compliant for fuels and lasted only 8 years.

 

[Comodave]

It could be old fuel hose slightly leaking. With sewage hose you can wet a clean cotton cloth and lay it on the suspect hose and then smell the cloth to see if it smells like sewage. You might try this and see if it smells like diesel. I have no idea if it would work but maybe worth a shot???

 

[Duvie]

I had a gasoline boat that had cheap nonrated fuel lines. I always had a gas smell and was sure I had a leak somewhere but could never find it. I Replaced all fuel lines with A1-15 rated lines and the smell disappeared. Smell your hoses or run your hands down them and smell your hands. If diesel smell is noted you need to change out your lines.

 

[Giggitoni]

Are you sure you put the diesel in the fuel tank and not your waste holding tank?

 

[Max1]

We've had our boat for 3 years, and last spring was the first time I ever filled the tank to the top. That was when we discovered a pinhole around the filler neck, and yes...dieselstink!. After I hit it with a wire brush attached to my drill, the holes became quite noticeable.I purchased some gas tank putty. It's a two-part mix like an epoxy that is supposedly fuel resistant. I patched the holes with it. Then it's best if you paint the tank to improve its resistance to further pinholing. I prefer white rust paint because it is easier to spot any future leaks.