Filling the tank

[dvdude]

Hi All,

I've had my '02 C4 vab for only a month, but I've noticed that when my tank is filled (NJ - we're not allowed to do it ourselves), it's never really full. The gauge reads full but after only a couple of miles, it'll drop to just above three quarters.

It's not a gauge issue. The car was full when I picked it up from the dealer and remained so for most of the drive home. The cost of the gas seems to reflect a lower qty than I expected. The net result is that I think I'm visiting the gas station more regularly than I should.

Could this be related to the flexible pipe issue I've read about here or is it simply that Porsche aren't training gas attendants like they should :D

[Loren]

TSB 1/04 2066 Incorrect Fuel level Display In Instrument Cluster (dated 3-26-04)

Model Year: As of '02

Concerns:

After refueling, the fuel level display in the instrument cluster does not show a change in fuel level. To correct this the fuel pressure pipe in fuel tank needs to be rerouted.

Information:

If malfunctions of the fuel level display occur after refueling, or if the fuel level display does not show a change in fuel level after refueling, there is the possibility that the fuel level float sensor is blocked by the fuel pressure pipe in the fuel tank. On vehicles with this complaint, the routing of the fuel pressure pipe in the fuel tank must be altered as described in the following work procedure.

You likely need to have a dealer perform this TSB update.

[dvdude]

Thanks for the info Loren,

The fuel level indicator does move after fueling (in fact, the DTE indication I have from the OBC shows range increasing WHILE it's being fueled, which is kinda neat!). The cost to fill seems a little low too - somewhere around 9 gallons with the car having much less than a quarter of a tank prior to the stop.

I'll have the dealer check it out, but it seems to be more closely related to pressure buildup in the tank filler causing the pump to switch off early, rather than an erroneous indication.

Edited June 28, 2005 by dvdude

[Loren]

Well, on C4's there is another issue (which I think is in the owners manual). If you disconnect the battery with less than 1/4 tank and then fill the tank - the calibration will be off.

[djantlive]

Sometimes the pump will stop early but the tank isn't quite full. Was it reading full when you pulled out from gas station only to have it drop 1/4 of a tank within a few miles?

[MannysTurbo]

Its funny you should mention this because on my 01' 996 TT, if I do not put enough gas to fill it at or about 1/2 tank the fuel level display will remain all the way down, and the remaining miles will show '---' as it shows when there is like 10 or less miles left. I just began to notice this recently, and I do find it very odd...certainly something wrong there.

[dvdude]

Sometimes the pump will stop early but the tank isn't quite full. Was it reading full when you pulled out from gas station only to have it drop 1/4 of a tank within a few miles?

<{POST_SNAPBACK}>

YES! Exactly that. Funnily enough, when I filled up yesterday, it cost more and the gauge behaved like I think it should. Remained on full all the way home (about 22 miles). I filled at the same gas station, but a different attendant was working. When it clicked off, he retracted the nozzle a little and topped it off.

Loren - the battery has never been disconnected AFAIK, but the car's going in for a Nav/DVD install on Friday, I'll make sure it's full before I drop it off, just in case.

Thanks for the info.