Getting rid of engine fumes

[CamdenDave]

I have a 18ft bowrider (1987) with a mercruiser v8. While on the water we can smell fumes from the engine area. Any simple fix?

 

[Baylinerchuck]

What fumes, exhaust? Fuel? Is your bilge blower running?

 

[CamdenDave]

Not exhaust, it is more just the smell of an engine running. Bilge blower not running.

 

[Thalasso]

No simple fix for exhaust fumes. If that's what your referring to it is called the station wagon effect. I'll bet if your running into the wind your not getting this

 

[MH Hawker]

turn on the blower thats what its there for

 

[Horigan]

I had a mild fuel/engine smell we couldn't get rid of or find the source, until we replaced all the fuel hoses. After a while they start to breakdown and exude fuel vapor. Apparently this is more prevalent when ethanol gas is used.

 

[CamdenDave]

The blower is designed to run the entire time the engine runs? I thought it was just used to flush the engine compartment of fuel fumes before starting?

 

[tpenfield]

Not sure what the smell of an engine running exactly is, if it is not exhaust, are you saying it is more like gasoline?

​Not safe if it is gasoline . . .

 

[CamdenDave]

I read a few discussions y'all had on blower use. It was interesting. Never thought the engine is not pulling in enough air at idle to push all the air out. So manufacturers suggest running the blower.

This is when we noticed we could smell the engine running. While we were putzing along in the no wake zone. We have owned sailboats for the most part. On the rare occasions we ran the diesel, there was no smell....it was also not right next to us.

 

[tpenfield]

I read a few discussions y'all had on blower use. It was interesting. Never thought the engine is not pulling in enough air at idle to push all the air out. So manufacturers suggest running the blower.

This is when we noticed we could smell the engine running. While we were putzing along in the no wake zone. We have owned sailboats for the most part. On the rare occasions we ran the diesel, there was no smell....it was also not right next to us.

The only 'air' that the engine pushes out is the exhaust. So, if you have fumes in the engine compartment, the blower is the thing that is designed to pull the air out. You are supposed to run the blower for about 4 minutes before starting the engine and also keep the blower running at idle speeds. I just keep it going all the time.

Still wondering what an 'engine smell' actually is . . . :noidea:

 

[TyeeMan]

Make sure your breather tubes from each valve cover are firmly seated up against the flame arrestor. If they aren't you will get a little oil vapor (engine) smell. Or if your engine has a lot of blow by in the cylinders you might have excessive oil vapor coming out of the breather tubes and your engine can't ingest it fast enough.

Also, make sure your flame arrestor is nice and clean so it breaths properly.

As previously stated, anytime the throttle is at idle position, 4 minutes prior to starting, and anytime you're fueling the blower needs to run. When your up on plane moving out theoretically there is enough air flow into the engine bay that the blower is not necessarily needed.

 

[CamdenDave]

I would say that better describes the smell. A heated oil smell. Not fuel or exhaust. I will double check the tubes.

Thanks all.

 

[tpenfield]

Make sure your breather tubes from each valve cover are firmly seated up against the flame arrestor. If they aren't you will get a little oil vapor (engine) smell. Or if your engine has a lot of blow by in the cylinders you might have excessive oil vapor coming out of the breather tubes and your engine can't ingest it fast enough.

Also, make sure your flame arrestor is nice and clean so it breaths properly.

As previously stated, anytime the throttle is at idle position, 4 minutes prior to starting, and anytime you're fueling the blower needs to run. When your up on plane moving out theoretically there is enough air flow into the engine bay that the blower is not necessarily needed.

Just to be clear, during the actual fueling, everything should be off and all people out of the boat. Running the blower would come afterwards,

 

[TyeeMan]

Oops, my bad. Thanks for the clarification.