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IMO, this does not set a code for the vent valve, otherwise we would have a "smoking gun" for the elbow as that is a much more common failure than the vent valve.
Well that's bad news for me, as my old valve appeared to still be working just fine. So if the cracked elbow was NOT the cause of my P0441 code, then there's a chance that I'll STILL be in trouble. . . :( Well, all back together and driving now to try to get the test to run so we'll see shortly!
 

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Well that's bad news for me, as my old valve appeared to still be working just fine. So if the cracked elbow was NOT the cause of my P0441 code, then there's a chance that I'll STILL be in trouble. . . :( Well, all back together and driving now to try to get the test to run so we'll see shortly!
Maybe you'll get lucky! Jarring the solenoid around during the elbow replacement might temporarily fix it. My valve is starting to **** the bed. I got a code for it a few weeks ago. Cleared it and the light stayed off for over a week and 2,000 miles of driving. Cleared it again and it hasn't come back yet after another 10 days or so and another 2,000 miles. (I went on a road trip)
 

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Damn, first drive and already have the pending 0441 code again. Guess it's time to start taking a look at things back in the wheel well instead of up in the engine bay!
 

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Damn, first drive and already have the pending 0441 code again. Guess it's time to start taking a look at things back in the wheel well instead of up in the engine bay!
First try and trick things. It might be an air leak or other issues so try and just make it decide if there is an O2 change. It rules out some other things too. Unplug the mafs, and then keep them unplugged and see if there are no codes (for evap) and the EVAP system goes ready. That is at least a starting point. Each of the possible things happening or not points to a little different cause but at least you have a place to start.
 

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Unplug the mafs, and then keep them unplugged and see if there are no codes (for evap) and the EVAP system goes ready
Wait, how does this work? I thought part of the evap test was looking at the mafs, i.e. seeing things go rich from the fuel vapor while the mafs stay steady.
 

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Wait, how does this work? I thought part of the evap test was looking at the mafs, i.e. seeing things go rich from the fuel vapor while the mafs stay steady.
I works because that is the way they designed it.Unplugging the MAF is written into the car. When it goes into no MAF mode it adjusts its ways. Just try it, I will explain it as we go depending on your results.
 

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I works because that is the way they designed it.Unplugging the MAF is written into the car. When it goes into no MAF mode it adjusts its ways. Just try it, I will explain it as we go depending on your results.
Ok, I'll for sure give it a go then and let you know what happens! I guess it defaults to Alpha-N with no MAF signal, but still runs the 'rest' of the evap test?
 

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Damn, first drive and already have the pending 0441 code again. Guess it's time to start taking a look at things back in the wheel well instead of up in the engine bay!
Are you able to see what the BMW specific code is? What reader do you have?
 

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Alright, major update!! Has some bad news for this original topic though, it seems the 540i valve that I got indeed does NOT work for the M5! Anyway, @technician117 , my original issue was a BMW code 242 / OBD2 code P0441. @Sailor24 , I reset things and unplugged the MAFs and only got as far as seeing some MAF related codes (P0102, P0113, and P1117), but then I got to tinkering around and think I found the real problem. I removed the rear drivers fender liner to get a look at the evap tank and charcoal canister and to check the line going between the valve and the charcoal canister for leaks/function:
  • With the car off, I hooked +12v and ground to the valve terminals (see, I KNEW that was a GREAT idea to mount that thing some place accessible!!!), started the car, and made sure it was sucking vacuum back at the end of the line where it goes into the charcoal canister. Yep, sucking nicely, plugged it with my thumb, and the revs fell a little. So plumbing seems all good.
  • Disconnected 12v, valve closed, and verified NO vacuum suction at the line back at the canister under 'normal' status with the valve closed, check!
  • I then re-applied the 12v to the valve with the engine running but. . . no vacuum came back!!! I think that smaller solenoid in the M62 part isn't strong enough to pull open against the (presumably stronger) vacuum of the S62 engine at idle.
  • So I swapped back to my original old valve, and repeated the experiment. This time, the valve cycled as expected open and close with the engine idling!!!

I am thus concluding that the dumb little cracked plastic elbow and/or a sticky valve was the original cause of my issue, but while the repair work solved the elbow leak, my troubles remained due to the poor functionality of the new/cheaper 540i valve. I expect everything will be just fine now with the old valve back in there, but will report back in a few days after a few drive cycles to confirm!

And for now, hold on to and clean out your original valves folks, as the current evidence suggests the cheaper ones do NOT work properly on our engines sadly!!!
 

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I then re-applied the 12v to the valve with the engine running but. . . no vacuum came back!!! I think that smaller solenoid in the M62 part isn't strong enough to pull open against the (presumably stronger) vacuum of the S62 engine at idle.
I think something else might have gone on there, because that makes little sense. A solenoid is a solenoid. Might be the diaphram but I doubt it. The design of the device would allow for pressure in the tank when it opens, this would compound your more vacuum theory. The object of the device is to release the vapors in the tank and since the system is sealed when gas vaporizes it expands, even considering gas consumption from the engine. When you open your gas cap you should not get a rush of air either way. If you do then something is likely wrong. Did it go click? Only time will tell, but I suspect you might have missed something. First check the OHMs of both those coils in the devices.
 

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Solved! Old valve back in, all readiness monitors set, no more codes! And I did check the resistance of both solenoid coils. New/smaller one is about 25ohms and the original one is about 55ohms. The resistance by itself isn't enough for us to calculate the inductance of them, but that's OK, because it's both bigger and has more resistance, the M5 one clearly is a larger coil and thus creates a 'stronger' magnetic field to open it. So on the contrary, this now makes perfect sense. The internal diaphragm moves upwards in order to open the passage between the inlet an outlet. The smaller one clicks and opens just fine when it's sitting there. But when the engine is running, it's pulling vacuum on the lower port, and thus keeping the diaphragm 'sucked' closed, and even when energized that poor little coil just isn't strong enough to pull it open against the engine vacuum. I repeated the experiment several times with both valves to be certain, manually hooking them up to +12v and ground and the results were 100% consistent. I suppose it's possible the new valve is just a bad lemon, that's certainly plausible. See pics in this thread of a dissected valve showing the coil up on top by the connector, and the white plastic looking diaphragm in the bottom portion:
I still can't say with complete certainty however whether it was the cracked elbow or just a sticky valve that caused the original issue. I supposed if it comes back again in the near future that will point to the valve sticking, and another cleaning should temporarily fix it again. If it never comes back again, then that probably indicates the valve was good all along and the issue was the vacuum leak from the elbow. Sorry I can't be conclusive on this one, but at least we've identified that the 540i valve is NOT a suitable replacement for the M5. But since I have now have it such an accessible spot, I will continue the search for some 'other' valve that does have a strong enough coil to work on the S62 in order to avoid the now ~$330 asking price of the OE replacement parts!!!
 

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When you open your gas cap you should not get a rush of air either way.
Ah, I just realized you might be confusing this purge valve with the valve in the leak detection circuit (apologies if you're not), but they're two different things. This purge valve in the engine bay is normally closed, and only opens to allow the built up fuel vapors to be sucked into the engine from the charcoal canister and burned up:
The leak detection valve/pump assembly is back at/part of the charcoal canister, and this is the valve that can control whether the tank is open to vent to the charcoal canister or closed for the leak test:
The valve itself is part of #13 here, but I just disconnected #10 (the line coming from the purge valve up front) where the manifold vacuum sucks the vapors from the canister when the purge valve is open. The leak test/valve only operates when the engine is off. Make sense?
 

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Ah, I just realized you might be confusing this purge valve with the valve in the leak detection circuit (apologies if you're not), but they're two different things.
Of coarse I am not. Maybe you should read your links again. Leak detection is just that it does not do much more. Only purge valve takes the pressure out, or on euro cars releases a vacuum.
 

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Of coarse I am not.
Ok, my apologies then, I guess we're on the same page after all! At any rate, I am starting to wonder more if I didn't just get a bad new valve. Maybe I'll exchange rather than just return it to try a second one. If it can open against the 540i vacuum, it really should be capable enough to still open in the M5, right? I mean c'mon, it's not pulling THAT much more air at idle, sheesh! Will do that and report back again with the results of the new-new valve, I'm determined not to give up on this quest until we find a suitable alternative at a more reasonable price!
 

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I mean c'mon, it's not pulling THAT much more air at idle,
That is it in a nutshell. And magnetic force is not weak, or really adjustable in a device like that. That is why I am having problems. What your saying could be 100%, but when it is odd like this there needs to be other input. I know others have used different valve but never really seen an after report. Onward and upward.
 
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