When I spill gasoline and it flows into holes at 3 & 9 o'clock ... where does it go?

Steve530 · Nov 28, 2011

bluebee said:
Is that where the fuel that isn't squirted into the intake manifold goes? Back into the charcoal canister?

If so, isn't that a LOT of liquid fuel going back into the canister?

How does it get all the way back to the driver side rear wheel well from the engine fuel rail?

Fuel that isn't injected is returned to the fuel tank through the return fuel line (number 5 on the fuel feed diagram). I think the return fuel actually goes through the fuel tank suction jet pump. It does not go to the charcoal canister.

QSilver7 · Nov 28, 2011

We have liquid fuel that goes thru tubes & lines.
We have vapor that goes to the canister and evap purge valve
We have VENT tubes/hoses that carry vapor and air (not liquid).

Just as your homes drain pipes have VENT pipes...the vent pipes allows air to escape up and out of your home, while the drain pipes carries away waste water to your sewer lines or septic system. The VENT pipes are only for air to escape...the same type of set-up is used in our cars. There are hoses/lines/pipes that are either for air, vapor, or liquid.

When dealing with a closed system like our fuel tanks and injection lines...we must consider that filling the tanks will require some type of venting...there must be some type of overflow drain tubes that will carry excess fuel as well as allowing air pressure to escape. And our cars also have a system of recovering unburnt fuel which is mostly in the form of vapor...the canister collects this fuel vapor, and the evap purge valve expels this vapor into the exhaust manifold to be burnt instead of wasting it away to the atmosphere.

FUEL TANK (exert from familycardotcom)

Most automobiles have a single tank located in the rear of the vehicle. Fuel tanks today have internal baffles to prevent the fuel from sloshing back and forth. All tanks have a fuel filler pipe, a fuel outlet line to the engine and a vent system. All fuel tanks must be vented. Before 1970, fuel tanks were vented to the atmosphere, emitting hydrocarbon emissions. Since 1970 all tanks are vented through a charcoal canister, into the engine to be burned before being released to the atmosphere. This is called evaporative emission control and will be discussed further in the emission control section.

If the fuel supply system is not clear as how it functions...then reading up on the topic using the online BMW TIS and finding the PDFs on e38.org & e38.org/e39 will go a long way in grasping knowledge...even googling the topic...may prove to be very illuminating.

You can see in this TIS doc, that there is a VENT hose (air). The 2 holes seen when refueling...are probably 99% assuredly spillage/drain holes that allow excess fuel that leaks from refueling or fuel that may get spit back up while refueling to drain back down into the fuel filler neck...and back down into the tank: http://tis.spaghetticoder.org/s/view.pl?1/01/37/30

We must also remember that there IS a hose that sticks out from that side of the vehicle that is #12 (the battery vent tube)...again "VENT" tubes carry air/gaseous vapors. I don't have the sedan...so are you 100% sure that the tip of the hose encircled in red is NOT the battery vent tube (#12 in the diagram)?:

uncmozo · Nov 28, 2011

I don't like to add confusion to an already confusing thread, but is it possible the tube coming through the fender liner is the water drain for the moonroof? I know there is a drain on the right and left sides of the moonroof.

Jerry

Steve530 · Nov 28, 2011

QSilver7 said:
...so are you 100% sure that the tip of the hose encircled in red is NOT the battery vent tube (#12 in the diagram)?...

Yes, I am certain that the hose is connected to the small hole at the bottom of the filler tube gasket. I blew compressed air through the hole and it came out the tube below the fender well.

The gasket is outside of the fuel and vapor recovery system. The hole is at the bottom (6 o'clock) position in the gasket. It's very small and likely to be covered with dirt. Take a good light and inspect the gasket at this position. I used a can of compressed air with a small straw attached (computer duster) because I didn't want to put a lot of pressurized air through the system if I was mistaken.

Check the diagrams, you'll see this hose is attached to the back of the filler gasket.

QSilver7 · Nov 28, 2011

Steve530 said:
Yes, I am certain that the hose is connected to the small hole at the bottom of the filler tube gasket.... The hole is at the bottom (6 o'clock) position in the gasket. ... Check the diagrams, you'll see this hose is attached to the back of the filler gasket.

Then that would probably be the #2 vent hose which is identified by you & the TIS (see the link I inserted in reply #22 to the TIS...which is identified in the 2nd image) You can see it running from the bottom of the filler neck, then into a hole in the fender, then down & out of the bottom like in the pic you posted.

Steve530 · Nov 28, 2011

QSilver7 said:
Then that would probably be the #2 vent hose which is identified by you & the TIS (see the link I inserted in reply #22 to the TIS...which is identified in the 2nd image) You can see it running from the bottom of the filler neck, then into a hole in the fender, then down & out of the bottom like in the pic you posted.

I think it's a drain for the filler neck recess in the body, not a vent for the fuel system. I've circled the place on the TIS diagram where I think it connects.

The hole is clearly visible in Bluebee's immaculately clean gasket. I've annotated the photo below.

bluebee · Nov 29, 2011

QSilver7 said:
our cars also have a system of recovering unburnt fuel which is mostly in the form of vapor...the canister collects this fuel vapor, and the evap purge valve expels this vapor into the exhaust manifold to be burnt instead of wasting it away to the atmosphere.

This is a wonderful team effort where we try to figure out HOW the fuel system vents, drains, vapor recovery lines, etc. work.

One minor question as I read (and reread multiple times) the responses above, didn't you mean "intake" manifold above?

I think you did simply because the charcoal canister hose seems to go to the purge valve which has a hose which seems to go to the intake manifold (not the exhaust manifold). Right?

QSilver7 said:
back down into the tank: http://tis.spaghetticoder.org/s/view.pl?1/01/37/30

This is a nice diagram showing the OTHER SIDE of the fuel filler hole!

Here it is in 800x600 pixel screenshot format to make it easier for others to see:

JimLev · Nov 29, 2011

bluebee said:
And, I don't know of any good pictures of the E39 charcoal canister yet.

Here's the Evap and charcoal canister pics.

Shires · Nov 29, 2011

doru said:
All the overflow in the engine is re-circulated back into the charcoal canister.

Pretty sure the M54 has a return-less fuel system, at least here in Europe.

JimLev · Nov 29, 2011

Shires said:
Pretty sure the M54 has a return-less fuel system, at least here in Europe.

When the fuel pressure regulator was moved from the engine bay and put in the end of the fuel filter the fuel was returned to the tank from the filter to control the fuel pressure.
So it is still a return system, just not from the engine. This move was to keep the fuel temp that was returned to the tank a bit lower. It also increases BMW's profits because you have to purchase a new regulator with the filter.

bluebee · Nov 29, 2011

JimLev said:
Here's the Evap and charcoal canister pics.

Thanks for those wonderful pictures!

I had searched all the E39 related threads with the charcoal canister embedded in the title ...
- charcol cannister
- Charcoal Evap Canister Potential Problems
- New Member Introductions > bmw e39 528i charcoal canister location
- where is the evap canister on 2000 528i?
- anister Purge Solenoid
- Charcoal Evap Canister Potential Problems
- 540iT puddle of oil around the filter canister...???
- How Long to Replace a VAPOR CANISTER?
- HAS anyone replaced their VAPOR CANISTER???
etc.

... and I had not seen 'any' pictures of the E39 charcoal canister; so these two pics are a wonderful value addition. Thank you for taking the time to snap them.

When I look at the diagram in post #6 above, I don't yet understand which picture is of which part.

For example, looking back at my particular diagram:
- 2002 E39 525i => Fuel Supply => Ventilation => EXP.TANK/ACTIVATED CARBON CONTAINER

I see there is a part #11 (Activated Charcoal Filter) & two other parts that might be the other picture (#12 Leak Diagnosis Pump & #13 Dust Filter).

Since neither looks exactly like the pictures above, is the presumption below correct?

Is this #11 (Activated Charcoal Filter)?
(and is it in the correct orientation?)

Is this #12 (Leak Diagnosis Pump)? And is it in the right orientation?

Steve530 · Nov 29, 2011

I've annotated Jim's photos for some parts. I'm not sure if I've appropriately identified the vent pipe in the first photo.

In the second photo, I'm not sure if I've identified the fuel tank breather line correctly.

bluebee · Nov 29, 2011

Steve530 said:
I've annotated Jim's photos

Wow. I didn't even realize there 'was' an "Expansion Tank" in the driver side rear wheel well!

I see the expansion tank now, in the diagrams in post #6 above as:

- 2002 E39 525i => Fuel Supply => Ventilation => EXP.TANK/ACTIVATED CARBON CONTAINER
- For vehicles produced from 09/01/2000
- 01 EXPANSION TANK, Qty=1, 09/2000, PN=16131183814, $149.61

Steve530 said:
I'm not sure if I've appropriately identified the vent pipe in the first photo. In the second photo, I'm not sure if I've identified the fuel tank breather line correctly.

Using your annotated photo as a start, I just found the attached TIS 11.09.20.3 for the E38 & E39 New Evaporative Charcoal Canister Purge Line.

I don't profess to understand it though ... so may I ask if it answers these two questions you had?

Steve530 · Nov 29, 2011

I think it tells me that I identified the vent pipe incorrectly.

Neat TIS, though. Spiders crawl into vent pipe, vent pipe gets clogged with spider webs, and fuel pump pulls enough vacuum to collapse gas tank because the vent is clogged. Solution is screen - over vent pipe.

JimLev · Nov 29, 2011

Here's another shot with the parts removed. I took them out just to get a look at where all of the lines went and to clean the dirt off of the inside.
This was back when I changed springs and installed Koni FSD's about 4 years ago, from my pre-blue powder coating days. I liked red back then.

Steve530 · Nov 29, 2011

Jim,

Is that blck line or blue line running over the top of the expansion tank open to the atmosphere? It's supposed to have a screen to prevent spiders from crawling into the vent.

Not like I think there's a chance of a spider in you garage. You must spend a lot of time cleaning.

BTW, what did you replace the Koni FSDs with?

Steve

bluebee · Nov 30, 2011

Steve530 said:
Is that blck line or blue line running over the top of the expansion tank open to the atmosphere? It's supposed to have a screen to prevent spiders from crawling into the vent.

I see you (Steve) understood that four-page warranty repair document better than I did.

Re-reading it a few times, apparently, when fuel leaves the fuel tank, air from this screened purge-line (i.e., vent line) goes into the charcoal canister and then into the fuel tank to replace the missing fuel.

If this "purge line" gets clogged, it can't be cleaned (according to the TIS anyway); it must be replaced.

Otherwise, the fuel tank partially collapses, causing knocking sounds while driving and hissing sounds while removing the gas cap (or so the TIS says).

JimLev · Nov 30, 2011

Steve530 said:
Jim,

Is that blck line or blue line running over the top of the expansion tank open to the atmosphere? It's supposed to have a screen to prevent spiders from crawling into the vent.

Not like I think there's a chance of a spider in you garage. You must spend a lot of time cleaning.

BTW, what did you replace the Koni FSDs with?

Steve

Steve,
The black and blue lines are difficult to say where they go after they go into the body, see pic. The blue one does connect to the dust filter.
I was installing Koni FSD's when I took the pics, they are still in the car with ~50K on them and are still working fine.
I do have some spiders in the garage, they like to come in during the winter...a heated garage does have a few negatives.
I don't spend a lot of time cleaning, I just don't drive it when the weather is bad or in the winter. I use to have 4 cars, but I'm down to 3 now, so the 540 doesn't see snow or salt.
It's always been a winter garage queen.

Steve530 · Nov 30, 2011

bluebee said:
I see you (Steve) understood that four-page warranty repair document better than I did....

I had to re-read it a few times, too.

I guess not every part was over-enigneered.

Steve530 · Nov 30, 2011

JimLev said:
Steve,
The black and blue lines are difficult to say where they go after they go into the body, see pic. The blue one does connect to the dust filter.
I was installing Koni FSD's when I took the pics, they are still in the car with ~50K on them and are still working fine.
I do have some spiders in the garage, they like to come in during the winter...a heated garage does have a few negatives.
I don't spend a lot of time cleaning, I just don't drive it when the weather is bad or in the winter. I use to have 4 cars, but I'm down to 3 now, so the 540 doesn't see snow or salt.
It's always been a winter garage queen.

The TIS says that the line that is to be replaced attaches to the center of the fitting on the top of the carbon canister. So that looks to be the black line that is supposed to be open to the atmosphere. But that TIS is pretty old, so maybe it was re-designed. Anyway, my guess is that the blue line is the hose that foes to the purge valve. I think the filter is just to protect the orifice in the diagnostic pump.

I started to buy Koni FSDs, but read about problems with them and decided to go with Bilstein HDs instead. They are a bit harsh, but I prefer to think of them as controlled.

The car and garage look great.

Thanks for taking time to post the photos.

When I spill gasoline and it flows into holes at 3 & 9 o'clock ... where does it go?

Steve530

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