It's not a common problem, but I typed /charcoal f3 in the bestlinks and this came up, where you might be able to both benefit from and to add value...
- Fuel injection LDP leak detection pump DIY (1) & a fuel system charcoal canister DIY (1) & where is the fuel tank breather valve (1) & does spilled gasoline go into the charcoal canister (1)

 

You may find that the newer canister doesn't fit. Unless you can look at both canisters side-by-side, probably best to get the correct P/N.

 

Are you speaking from experience? I am certainly not wanting to buy something that wont function as good as the original. I am not looking to mod anything into place either. Just simply wondering if anyone else has had them side by side.

I did some searching prior to this thread's conception. The vehicles in question in the threads I have come across seem to be pre 09/00, albeit only one or two threads but one was a 97, the other a 2000. Im just curious if the design was changed. Just for the sake of knowledge, and knowing the change came because the earlier units caused the vapor valve to suck liquid gas up upon canister failure! . It took my canister 180k miles so im not too worried about longevity in the replacement.

BTW!!!!

Code is P0440, from what ive read the general consensus is bad charcoal canister. Which ive kinda had the feeling something was causing bad mpg other than my lead foot, along with pressures relieved when unscrewing the gas cap. Anything else i should consider replacing with it?

 

If you search this link for "bmw e39 e38 fuel supply system description" the PDF describes various iterations of the system including evaporative control, which should give you a notion of what might have changed.
http://www.bimmerfest.com/forums/showthread.php?t=165198&page=2

 

Awesome, thanks for that!

 

The charcoal in the canister will remain *good* for a very long time. It will marginally change your running parameters and your gas mileage. The purge valve is another story, but as long as you are not setting any codes, why even mess with it. They can go bad with contaminated charcoal, but generally only if you repeatedly over-fill your tank with gas. I would NEVER replace this canister if I were not getting an error and then I would remove the purge valve first, bring it inside the house or the garage and try to blow through it. You should not be able to blow through it at all. Then put 12VDC to the two connectors (polarity not important if removed from car). You should hear the purge valve "click" and with power still applied, you should easily be able to blow through it. If it does not click or the solenoid shift to where you can blow straight through it, then clean the valve with gasoline or a silicone lubricant to get the plunger free to where it does shift back and forth (open and closed) with 12 VDC applied. If you can not free up the solenoid with it soaking in gas or drenched with a spray lubricant to where you can blow through it energized, then it is time to change out PLUS you would be getting the SES coming on. If you clean the purge valve with anything besides gasoline, then you will want to dry it out well after soaking it in mild dishwater soap and water. Dry the valve while energized and open. This may be over-kill removing all that you may have sprayed into the valve, but I don't trust many chemicals remaining in and on the guts of the valve. G/L

 

The purge valve is another story

If I had the P0440, the purge valve would be on my list of things to test (along with the gas cap), well before I messed with the charcoal canister.

They can go bad with contaminated charcoal, but generally only if you repeatedly over-fill your tank with gas.

While lots of people say that spilled liquid gas goes into the charcoal canister, I can't find any reliable evidence that overfilled gas actually goes into the charcoal canister:
- Does spilled gasoline go into the charcoal canister (1)

I would NEVER replace this canister if I were not getting an error and then I would remove the purge valve first, bring it inside the house or the garage and try to blow through it.

This is good information for the purge valve threads. I will try to find a good one to append this to, so that others find it easier.

Unfortunately, typing /purge in the bestslinks only nets me one hit outside of bimmerfest, and one PDF:
-BMW_TIS_11.09.20_3_SI_E38_E39_New_Evaporative_Charcoal_Canister_Purge_Line.pdf (62.1 KB, 639 views)

But that PDF seems to be related to the purge line (not the purge valve)...

Separately, I'll search for a canonical purge valve thread to link to in the bestlinks, so that the next person finds purge valve information easier.

 

Running the obligatory e39-only title-only search for "p0440" nets the following:
- Need Help With Code - P0440 OBD II
- Some work ahead P1071, P1074, P0440
- 530i 2001; service engine soon P0440
- P0440 OBD 2 Codes 2001 530i

Interestingly, three of those four threads were by the same person, so it's certainly not a common problem here.

Expanding the search to include the E46 found nothing additional, but expanding the search to include thread content containing P0440 found 71 items (which I'll leave to the OP to peruse).

Expanding the search to Google found tons of information, for example:
- Check engine light - code PO440

I had this happen over the summer.
I had a p0440 and ses for the gas cap.
Retightened the cap, reset the code and it came back.
Then bought a new gas cap, reset the code and it came back again, but changed to a p1445 or p1447. Something like that.
Like yourself, I researched and saw my DM-TL (Diagnostic module - Tank Leak) was probably faulty. Picked up the tank for around $100 and it took about 15 minutes to change out, from jacking the car up to lowering the car back on the ground.

For a DIY, I still might make one, but here's the procedure in words rather than pictures.

Jack up car, remove drivers side rear wheel.
Pull out the pins and small screws which hold the fender liner in place.
Remove fenderliner from the car.
Towards the rear of the car, in the upper portion of inside the fenderliner, you'll see the tank.
Its got a wire which you should unplug first.
Then disconnect the line on top of the tank by squeezing the tabs and lifting the line up.
Theres three small torx screws on the bracket which holds the tank in place, remove those.
Then pull the tank towards the front of the car, and the other line will disconnect from the charcol canister.

Install is the reverse of removal. BUT dont forget to move the rubber o ring (dmtl pump -> charcol canister) from the old pump and put it on the new one.
Also, dont forget to plug in the tank!

(I was doing a few projects at once, and put the whole thing back together, fender liner and all and drove around the block with the same code before I realized I forgot to plug it in!)
Weeks later and no codes ever since.

Online TIS is the Sh!znit.
http://tis.spaghetticoder.org/s/view.pl?1/06/64/15

Goodluck!​

Last edited by guttershark; 11-30-2011 at 09:34 PM.​

- For people with the EVAP - P0440 Check Engine Code. Quick Easy Fix.- P0440 BMW - Tank Venting System
Function

Well, I***8217;ve been dealing with an annoying EVAP Check Engine light P0440 code for some time now.

I think I have a quick easy fix for you guys with the same problem.

I bought a new gas cap from the BMW dealer ($14), put it on but it kept coming back.

In a brain storm, I took the old gas cap and the new gas cap, laid them side by side. I took both O-Rings out of the 2 gas caps. I took the new gas cap, put the old O-Ring in first, then put the new O-Ring on top of it to see if that would really create a tight seal.

Well it worked. No more Check Engine Light, and its a very tight fit when you turn it into place.​

- Unidentified fault code......"P0440 Evap Purge"

I had this code in conjunction with a tank venting valve problem at around 28K miles.

Have them check the entire fuel vapor recovery system including the TVV.

Note. If you choose to ignore the code, then at least clear the code. If you don't the computer will eventually change the fuel map for to a more conservative setting and you will notice a drop in performance.

- Code P0440 came on tonight

There is some info in this link: starts on page 17-
http://www.bmwmotorsports.org/BMW_docs/m54x5.pdf

P0440 BMW - Tank Venting System Function Possible causes
- Missing or loose fuel cap
- Incorrect fuel filler cap used
- Fuel filler cap remains open or fails to close
- Foreign matter caught in fuel filler cap
- EVAP canister or fuel tank leaks
- EVAP system hose leaking
- Fuel tank leaking
What does this mean?

Tech notes
The P0440 code means that the control module has detected a leak in the Evaporative Emission (EVAP). Loose fuel tank filler cap is the most common cause that triggers the P0440 code.
What does this mean?

When is the code detected?
Malfunction is detected when EVAP control system has a leak, EVAP control system does not operate properly.
Possible symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Possible a noticeable fuel odor caused by the release of fuel vapors
P0440 BMW Description
The Engine Control Module (ECM) tests the Evaporative Emission (EVAP) system for the following conditions:
- Large and small leaks
- Excess vacuum
- Purge flow during non-commanded conditions
- Fuel Level and Fuel Pressure sensor faults
- EVAP Purge and Vent Valve faults
The ECM monitors the Fuel Tank Pressure sensor in order to determine the level of vacuum/pressure in the EVAP system. The ECM commands both the EVAP Purge Solenoid and the EVAP Vent Valve ON when the conditions are met in order to apply an engine vacuum to the EVAP system. The ECM commands the EVAP Purge Solenoid OFF once the system has reached a predetermined level of vacuum. This test verifies if a vacuum can be achieved in the EVAP system. Failure to develop a vacuum may be caused by a large leak or a restriction.

Even though I only searched for a minute (it took more time to cut and paste than to run the searches), I wouldn't jump to any conclusion about the charcoal canister being the culprit, without the classic debugging process, which is:

a. First understand how the system works,

b. Then understand what the code is telling you is not working,

c. Then test THAT system thoroughly (if it's not working, it will fail the tests).

Replace only the part that fails the diagnostic tests.

 

The fuel vapor recovery system is relatively unknown to me, and, since mine hasn't failed, I'm not the one to figure it out for you; but these documents found by typing /fuel_ in the bestlinks should help you better understand how to troubleshoot...
- BMW_E39_E38_Fuel_Supply_System_Description.pdf (211.0 KB, 1167 views)
- bmw_e39_e46model_MS42 MS43_ECM_M52TU_M54_engine_fuel_system_training_material.pdf (8.04 MB, 35 views)

See also:
- How does the E39 fuel injection FI system work (1)

 

Ok small update, still have not purchased a new canister as i wanted new and they are expensive! I got in this morning and it seems like the system has fixed itself or is trying to.

Beforehand, the analog mpg needle was very random, like stopped in neutral, the needle would bounce around- 7mpg, 20mpg, etc. when it should be maxed out. Or if i were cruising at 70 and put in neutral it would stay at whatever i was getting in gear, sometimes slowly creep up to 40, again when it should max out. Performance was definitely affected depending on if the needle was where it was actually supposed to be or not.

Like i said, problem kind of fixed itself for the time being. This morning i notice the needle was trying hard to function properly, and i was able to help it if that makes sense, kind of like slowly dislodging junk stuck in a shop vac hose using suction and a flat surface.

I looked at the realoem diagram of the fuel breather system, and noticed the expansion tank. my problems remind me of a stuck thermostat or something, or a coolant tank bobber stuck from gunk. Anyone know what i need to replace here based off my observations, or do i need to visually inspect

 

Ok small update, still have not purchased a new canister as i wanted new and they are expensive! I got in this morning and it seems like the system has fixed itself or is trying to.

Beforehand, the analog mpg needle was very random, like stopped in neutral, the needle would bounce around- 7mpg, 20mpg, etc. when it should be maxed out. Or if i were cruising at 70 and put in neutral it would stay at whatever i was getting in gear, sometimes slowly creep up to 40, again when it should max out. Performance was definitely affected depending on if the needle was where it was actually supposed to be or not.

Like i said, problem kind of fixed itself for the time being. This morning i notice the needle was trying hard to function properly, and i was able to help it if that makes sense, kind of like slowly dislodging junk stuck in a shop vac hose using suction and a flat surface.

I looked at the realoem diagram of the fuel breather system, and noticed the expansion tank. my problems remind me of a stuck thermostat or something, or a coolant tank bobber stuck from gunk. Anyone know what i need to replace here based off my observations, or do i need to visually inspect

 

Guess i answered my own question again, i may get in there after work today, im thinking that there is a plunger in the expansion tank (for the charcoal fliter) not sealing or has gunk in its travel path, just trying to avoid spending $350, at least so soon.

 

I replaced my sucking jet pump, charcoal canister, good to go.

Traced my leak down to the sucking jet pump, which is actually more than just an oddly shaped piece of plastic. There are filters and flaps inside that thing, so if it fails it can def cause problems.

#1 in the diagram...

http://www.realoem.com/bmw/enUS/showparts?id=DN53-USA---E39-BMW-540i&diagId=11_2675

When i went to pull the jet pump off from the brake booster line its attached to, the booster line tore at one of its bends. Luckily, i had the correct diameter hosing and enough plastic barbs to make it better than original. However, you may not be so fortunate, it is a GOOD idea to look over the hose prior to ordering a new sucking jet pump, if it looks bad, add it to the cart as well. Actually, just add to the cart, youll likely tear it just inspecting it and then you will be SOL.

#16 in this diagram, I THINK

http://www.realoem.com/bmw/enUS/showparts?id=DN53-USA---E39-BMW-540i&diagId=11_1502

UPDATE: this is only for models up to 98. Going to try to find the correct hose again. You NEED it. The bends in it are functional as well, ive learned...some 5k miles later...

 

I just purchased a 1997 540i happy to get it on the road and drive took it to a gas station after car bogged down and left me on the side of a freeway at quarter tank of gas

 

Heard it was from air being sucked into other tank? Was told to put gas so I filled up until pump stop to find gas leaking under passenger side fender well a good amount got on driver side about 5 minutes later and saw gas running from driver side as well

 

Trying to figure this one out my first 5 series

 

SophieVinAZ, if I were you, I'd start a whole new thread, titled something like "Gasoline Leak Near Fuel Tank Left Me Stranded." That might bring you more responses. I think you're going to have to get the car up in the air so you or someone else can inspect the area, looking for the highest wet spot.

 

Accidental overfill in my e60. Gas smell under drivers back rear. Will this go away? No codes no leaks??

 

Wrong forum. However, you may have a defective vent hose. Read this thread: http://www.bimmerfest.com/forums/showthread.php?t=988234

Your car may be different.

 

Thanks and my bad.