Refueling Problems

BigWalmac · #1 12-03-2013, 02:40 PM

Hey guys -

So My wife's X5 has been a trooper. 2001 3.0 with almost 230,000 miles on her. Over the last year, however, I have had an increasing problem.

When we fill the X up, at almost any gas station (Costco, Shell, Exon, etc.) the fuel pump pops and stops filling as if the X is full, when in fact it is not. Sometime this happens at 3/4 full, sometimes it happens almost every gallon from the 1st gallon up. I know that I have a 22 gal tank, so on refill if I only add 10 gallons, I know I'm not there yet. It is as if the tank is not venting properly or something.

For a while I thought that filling the tank very slowly helped, but that doesn’t always work... also, sometimes the pump will keep filling and overflow down the wheel well - this will happen even if the tank isn’t full. I can’t figure it out, but refilling is getting to be a major problem.

I can’t figure out what is causing this. Any ideas? Anyone seen this? Any suggestions?

One side note... about 6 months ago I had this problem. I filled the tank slowly, I don’t think I even got it completely full, and in the following days the X smelled like gas. I took it into the mechanic and they said there was gas on top of the tank in the saddle wells. They drained it and the smell was gone. Beyond that, however, they had no suggestions for why this would happen and noted no leaks on the tank elsewhere. I haven’t had issues with the smell of the tank since.

Part of me thinks it maybe a full charcoal canister or something, but I'm not sure how that ties into refueling...

I appreciate the help!

Brandon002 · #2 12-03-2013, 02:46 PM

You have an issue with ventilation in the gas tank.

My guess would be a faulty fuel tank vent valve. It's an 85 dollar part at Autohausaz.com

BigWalmac · #3 12-03-2013, 03:43 PM

Hey Brandon -

Thanks for the reply. One question... the name certainly fits as the problem, but it seems like that part is located on the engine block... is that where the fuel tank really vents from? I woudl have thought it would vent closer to the fill up stem...

Otherwise, I found the part. A quick search renders a few (non-X5 DIY's) Any sudgestions for an X5 DIY install?

Brandon002 · #4 12-03-2013, 04:02 PM

I've never had to replace one of these, so I'm not sure on the DIY.

I've replaced them on other cars, just never a bimmer.

I'm sure it's a pretty straight forward job if you can locate the part.

BigWalmac · #5 12-03-2013, 04:16 PM

Can anyone else confirm this?

From my research it looks like this returns fumes to be burned by the engine. I'm not sure how this interplays at fill up, other than again, the name matches perfectly.

Thanks to all

Brandon002 · #6 12-03-2013, 04:28 PM

I believe when the engine is off, the vent opens to allow vapor to escape during refueling. When the engine is on, the valve closes so that vapors are burned through combustion. That's how it works on just about every car made, don't see why BMW would be any different.

I've actually worked on other cars where cleaning the valve out thoroughly with throttle body cleaner "unstuck" the valve and it worked again. Although usually stuck again in a month or two.

Helihover · #7 12-03-2013, 05:13 PM

Different engine but, With my experience the fuel cap was sometimes hard to pull off (like it was sucked on there), the filler would click serval times (in Oregon attendants fill your tank so a few times I left without a full tank) and it throw the cel too. The valve on my ride is on the block and took about 2 mins to pull out. I cycled it several times with a 12 volt source and all has been well since. Or you can just replace it for about 80-100 bucks. Super easy DIY job. Are you getting a cel?

admranger · #8 12-04-2013, 01:52 AM

I tend to agree with you about the charcoal filter. Had this problem on two race cars. Figured out it was from jamming the fuel into the tank before enduros. Topping off the tank to the very top of the fuel filler hose and the associated track g-forces was causing not just vapors, but liquid to get sucked into the charcoal canister, saturating it. Not sure how it is happening on your X, but perhaps that vent valve and the filter together are the issue.

Good luck!

Zook_b · #9 12-04-2013, 03:27 AM

Mine does this as well. ><

racingbmwm3 · #10 12-04-2013, 01:34 PM

Vent/breather pipes going to the fuel expansion tank may be clogged, or charcoal canister is shot, or vent valve is having issues. Ideally, you'd get a CEL for the valve having problems.
Here's the diagram for the expansion tank and canister. Checking operation of the valve is easiest to do. Then I'd check for clogs in all the vent lines before replacing the charcoal canister. Also, I can't remember, but its possible hose 20 or 17 from the second diagram attach to the fuel filler neck and also provide venting while filling up and that hose should be checked for blockage.
RealOEM.com * BMW E53 X5 4.6is EXP.TANK/ACTIVATED CARBON CONTAINER