My 2009 128i won't take a full tank of gas. I used to only be able to fill to 3/4 but after it threw a code and I replaced the "leak detection pump".. Code went away. But the tank still stops around 7/8ths full.
Next step seems to be the charcoal canister. A new one is $330 and a local breaker has a "good used" one for $75. (Maybe less)
What I have read is that you can shake a canister and it'll feel and sound like a canister of salt. Also read you can blow through one if it's still working.
Anybody know how to tell if a used canister is any good?
Don't have an answer but I'd like to know as well
OHSCrifle said:
What I have read is that you can shake a canister and it'll feel and sound like a canister of salt. Also read you can blow through one if it's still working.
Both of these are right but I don't know if they are universals.
It may be due to a woeful lack of imagination on my part, but I'm having trouble imagining how a charcoal canister could be the cause. I know the E39 5-series has two tanks for weight distribution and a transfer pump that keeps the levels even. If that pump failed, I could see it being the cause.
1988RedT2 said:
It may be due to a woeful lack of imagination on my part, but I'm having trouble imagining how a charcoal canister could be the cause. I know the E39 5-series has two tanks for weight distribution and a transfer pump that keeps the levels even. If that pump failed, I could see it being the cause.
Me, too. Seems more that there is a check valve that is doing bad things- either in the filler neck or, more likely, the tank vent area that is causing the fuel to fill slow at the end.
1988RedT2 said:
It may be due to a woeful lack of imagination on my part, but I'm having trouble imagining how a charcoal canister could be the cause. I know the E39 5-series has two tanks for weight distribution and a transfer pump that keeps the levels even. If that pump failed, I could see it being the cause.
You've got me swinging. I am guessing that maybe the charcoal filter got a swig of liquid fuel down the vent and turned it into a solid block. So it can no longer function.
Here is the diagram - I am all ears if somebody thinks one of the hoses in particular could be blocked. Tell me which one and why you think so - and it might help me pick one to squeeze and investigate.
(Image source)
Edit to add: I also have a new filter for part #6 that I need to install.
There are only two vapor lines that are venting the tank- 13 & 10. Check those.
1988RedT2 said:
It may be due to a woeful lack of imagination on my part, but I'm having trouble imagining how a charcoal canister could be the cause. I know the E39 5-series has two tanks for weight distribution and a transfer pump that keeps the levels even. If that pump failed, I could see it being the cause.
The charcoal can break down and not pass vapors when filling the tank, so the fuel backs up in the filler neck and shuts the pump off.
The easy way to check for this is to disconnect the canister from the tank then go to the gas station. Assuming that you can get to the canister without removing subframes or something.
There's another possibility, though. If you have a saddle tank, there should be two fuel sending units. If one of them is stuck down (or is reading as if it were stuck down) then the tank may actually be full, but the gauge only reads half or so.
In reply to Pete. (l33t FS) :
I can't tell you, Pete how much I appreciate the knowledge and patience you give this community. I hope to give your science project a try. I'm just not sure if the car will go into a limp mode if I try to drive it without the canister in place.
It is not hard to reach in the E82.
