Could different diesel be causing exhaust smell?

[bsangs]

For the first 2-1/2 years of owning "Radiance," I'd refilled the fuel tank using only diesel from a local BP gas station. Fill a jerry can or two on way to the marina, go down below and pour it in. (My marina frowns on refueling in your slip, which is why I fill it down below, instead of up top.) Late last summer was the first time I used marine diesel. And the couple that brought her back from Edgartown after we were forced to cut our trip short motored most of the way, so the tank is completely filled with marine diesel now.

Here's the thing. My engine, a Yanmar 3GM30F, never emitted the slightest scent of exhaust when I was only using the BP diesel. But since the changeover to the marine fuel, the exhaust smell is very noticeable. There's no smoke after initial start up, and she still purrs like a kitten, but the scent is there. Could just be coincidence, I realize, but was wondering if a difference between marine and road diesel could be the culprit? Fuel turnover is very high in marinas around here, so I'm not thinking it's a bad batch of fuel. Not surprisingly, the internet is all over the place with differences between the two varieties. (For those that don't know, road diesel is green, marine is red.) Many say there is no difference, many say there is. So who knows. Just wanted to see what the opinions were here, since this group is more reliable than the internet in general. Thanks all.

 

[ConchyDug]

Off-road diesel is dyed red and no different than the taxed "highway" diesel.

You may live in an area where Diesel #1 and #2 is used depending on the season. Maybe they smell different because of the anti-gel additives for colder weather. Also sometimes they pretreat the fuel with Biobor at marinas which might have a Cetane booster.

 

[gabriel]

I’ve seen that many service stations now offering a blend of biodiesel at their pump. Bio diesel definitely has a different ‘bouquet’ than mineral diesel.

if I remember correctly from my diesel days, it was generally accepted that biodiesel provides superior lubricity (even down to a 15%) to de-sulfured mineral diesel.

 

[Pete the Cat]

I might think about the smell from your crankcase if you do not have the ventilation tube leading back to the intake. In the small compartments our diesels operate in, the engine can suck smell from the crankcase and leave it in the engine compartment. I noticed a remarkable reduction in smell when I routed the ventilator hose to the intake filter. Improved it a lot. FWIW

 

[David Grimm]

The street diesel is low sulfur. Not sure if the off highway diesel is. Something to look into.

 

[bsangs]

I might think about the smell from your crankcase if you do not have the ventilation tube leading back to the intake. In the small compartments our diesels operate in, the engine can suck smell from the crankcase and leave it in the engine compartment. I noticed a remarkable reduction in smell when I routed the ventilator hose to the intake filter. Improved it a lot. FWIW

Unless I'm misunderstanding you Pete, it doesn't smell down below in the engine room though, only from the stern exhaust port when it's running.

 

[Christian Williams]

I fill it down below, instead of up top.

How would you add diesel except from the required deck fill? I must be missing something....

 

[bsangs]

I fill it down below, instead of up top.

How would you add diesel except from the required deck fill? I must be missing something....

Tank is located in the v-berth. I just remove the cushions, lift the small board, unscrew the access plate, and pour it in. I also only have a float gauge for tank capacity - the gauge on the engine panel has never worked since we've owned her - so it allows me to confirm its accuracy.

 

[gabriel]

Tank is located in the v-berth. I just remove the cushions, lift the small board, unscrew the access plate, and pour it in. I also only have a float gauge for tank capacity - the gauge on the engine panel has never worked since we've owned her - so it allows me to confirm its accuracy.

WTH?? guess it’s better to spill diesel on your berth rather than your berth.

 

[bsangs]

WTH?? guess it’s better to spill diesel on your berth rather than your berth.

Four years, not a single spill (knock wood). Got some great diesel containers. Besides, it's not like I don't remove the cushions and lay down some towels before pouring it in. Also, come by my busy marina fuel dock sometime. Between the sail boats, power boats, tour boats, police boats, ferries and jet skis, once you're tired of waiting the half hour to get refueled, I'll pour some in down below for you.

 

[Christian Williams]

Aa you probably know, marine fuel tanks are specifically regulated and deck fills required. Good reason for it, as snaking a fuel dock hose belowdecks is asking for trouble, and for me, so is lugging down jugs. I suppose you can get away with it, but it seems far, far from optimal.

 

[bsangs]

Aa you probably know, marine fuel tanks are specifically regulated and deck fills required. Good reason for it, as snaking a fuel dock hose belowdecks is asking for trouble, and for me, so is lugging down jugs. I suppose you can get away with it, but it seems far, far from optimal.

Again, only while in my slip, so not frequently. When I want to top off with five gallons before heading out on a trip, that's about the extent of it. And I'd never snake a fuel dock hose down there. I'm not that stupid. Five gallon container only.

 

[Captain Pete]

I wonder if your tank under the forward berth was originally the optional 3rd water tank converted to hold and deliver fuel. I just added a project 35-3 to my fleet (and am still married...) and it has the 3rd water tank up there.

 

[bsangs]

I wonder if your tank under the forward berth was originally the optional 3rd water tank converted to hold and deliver fuel. I just added a project 35-3 to my fleet (and am still married...) and it has the 3rd water tank up there.

That's my screw up, Pete. Tank is in the Q-berth, not the V-berth. Apologies for the confusion. We have three water tanks, including one in the bow.