Please forgive me if this has been discussed before. There are too many diesel threads to dig through at the moment.

We have had our 09 35d for about half a year now. Over this time, I have never stopped at a pump where the diesel nozzle wouldn't fit. However, the other day I stopped at the same exact pump I always do and the security flap wouldn't open, so I went to another station and tried another pump that has worked in the past and got the same result. Keep in mind that these are not truck-stop nozzles, but the smaller typical nozzles you would find anywhere. The car hadn't been in for service or anything recently, so I knew it wasn't something the dealer did. I decided to remove the fuel cap on the car and take a look. I noticed that the metal security flap hinges from the top and is locked at the bottom. It becomes unclocked when the larger diesel nozzles put pressure on the top and bottom of the flap.

Bottom line is this, I think what happened in my case was that my wife and I typically remove the nozzle very slowly after refueling and by doing so, the security flap never actually locked at the bottom. Therefore, we never had any issues with any smaller/typical sized diesel nozzles. However, If I remove the nozzle fast, the flap has enough momentum to lock. Just a heads up for anyone that didn't realize this. If your car is like mine and you remove the nozzle slowly after refueling, you shouldn't have any issues with the smaller nozzles.

Also, why in the world does BMW utilize a locking system that isn't activated by the smaller diesel nozzles that the majority of the stations here use? I am picking up a nozzle adapter from my dealer this week, but from what I hear, those are adapters for the larger truck stop nozzles. Perhaps they also work for the smaller nozzles by opening the security flap. At any rate, I am going to be sure to just slowly remove the nozzle after fueling in order to avoid this issue at all.

EDIT: So now I understand that there are three major nozzle sizes in my general area. Small for gasoline, Medium for passenger car diesel and Large, which are typically truck stop sized for larger commercial trucks. Apparently, some stations are using the smaller, incorrect gas nozzles on diesel pumps when they should be using the medium sized ones. The X5 was designed for the medium sized nozzles. This is why you may run into an issue with the smaller nozzles.

Looks like I answered my own question, but maybe the tip about slowly removing the nozzle will work for others as well.

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Profeshenal spellar