i recently noticed the fuel tank won't fill to the max,

it only fills to 3/4 and stops,

i also noticed this happens randomly, sometimes it fills to the max with no issues

anyone faced the same issue? is it a fuel sensor only?

i am planning to take it to the dealer soon, just want to see if it happened to anyone?

 

This is a common problem whereby the fuel foams up due to the design of the tanks opening which causes the auto-cutoff of the nozzle to kick in.

To lessen the foaming you can either swivel the nozzle 180 degrees (that helps) or just fill it up with less pressure (slower) when it starts to foam.

Do a search and you'll find that you're unfortunately not alone.

 

I swivel the handle to the 9oclock position, works on my car..

 

Yeah, like everyone else.. If I fill very fast it seems like It cuts off early. I'm not sure I have ever seen it only go to 3/4's that seems pretty extreme to me. Usually it is just a gallon or two short of being full (I know I can get 16 gal US in it when it is almost completely empty)

Then again I am in Calif which has the gas station nozzles from hell because of the smog laws. So they tend to fill much slower and are much more fussy with cutting off early. But usually I just take my time and make sure I'm completely full.

Side issue, if there is one complaint I do have with 911's it is the fuel range. Have to fill up way too often. Wish like hell the tank was larger. Even the C4's have a couple extra gallons I believe over the C2's.. May think about a C4 next time just for that reason.

 

Is this why I can only get about 16 gallons on my C4S when it's almost empty? C4S has a 18 gallon tank right?

 

Yeah c4s are 18... With my c2s which is 16 And I've gotten 16 in it when on fumes. So I suspect the tank may be a little larger than 16... So I would think the c4s should be able to get close to 18 if you were almost empty..

That extra two gallons would be good for an additional 40 miles of range which is significant since it seems like I'm lucky to get 320 miles or so out of a tank...

 

I own my C2S for a year and 9 months and surprisingly this only happened to me twice within the last month. So i guess my issue is something else not related to the tank foaming up? Will take it in to the dealer this week and check

 

Are you sure it simply isn't the gas station /nozzle?

There isn't really much to go wrong here.. I think everyone has had pumps and cars that need to be "coaxed"a bit to get it full... Sometimes you just need to keep at it until you hear the gas getting to the top.. Reposition etc..

 

Like scatkins said -- there really isn't much that could be wrong here. The only thing that would be keeping you from filling your tank entirely is the gas pump nozzle. The gas tank isn't interfacing with the pump in any way, so there is no way your car is cutting-off the flow of fuel. Am I missing something? It is seriously doubtful that your 991 has received a smaller tank, or that there is any kind of blockage etc that might be limiting the fuel volume.

But after all the previous posts I am still not clear on the details of your issue. I would assume that when you fill the tank with gas, you get in the car, and you find that the DTE or fuel level gauge is not what you expected. If that happens, are you saying you physically can't get anymore gas in, or have you not tried? Meaning, you see the level is not full, so you get back out and start the pump and add more fuel. You would then see the level go up to "full" or whatever level you are trying to reach. Is this the case? Or, are you saying you think there is a problem because your level gauges and DTE are inaccurate?

Foaming or whatever condition that others have said might shut the pump nozzle off is something that is easily overcome, and relatively easy to identify as the culprit. Simply add more fuel after waiting a few moments. Slow the flow of fuel down (remember the rate of fuel flow is also dependent on the gas pump, the and even the pumps pulling fuel from the underground storage tanks).

Personally I would never assume the auto-shutoff nozzles to be the authority on whether my tank is full or not. Many pumps here in the NE US are broken or overly sensitive, so either I find they are shutting off prematurely every few moments or the other extreme - not shutting off even when the gas level gets to the top -- yikes!

Anyways, do a tiny bit of troubleshooting, you'll have your answer. Good luck and keep us posted.

 

I had the same thing happen a couple fill ups ago. Stopped at about 3/4 full, but I didn't realize it until I was back on the road. So I just put it on the lowest flow setting next time and it does fine. Problem solved.

 

to be honest I was so lazy taking it to the dealer just to investigate this issue, and good that I didn't, I previously had the same issue with my E46 M3 and the issue was related to the fuel tank so I expected the same. this time I decided to do my small troubleshooting, I found out that only when I fill up in the station newly opened next to my house I get this issue and I found that the flow is very high and fast, causing fuel to foam up and stop at about 3/4. I filled up yesterday in another station and it was filled up to the max with no issues.

 

Yep, turn handle so hose points up and it will fill every time.