Fuel Gauge Problem.

adrian996 · Jul 16, 2006

Hello all! Out in the car today in the wild hills of Wales - HOT! Ran a bit low on petrol - warning light came on and message on OBC read "Consider refueling.........." Only went a couple of miles after that. Refueled (not full, but about £40 worth) - allbeit with RON 95 - and off we went. Noticed fuel gauge hadn't moved - still on nearly empty. Pulled over, got out of the car, locked it and left it for a couple of mins. Got back in - still no good.

This has happened to me once before - exactly the same circumstances - and I have a feeling that it might be because I left the other half in the car while I was paying and didn't lock the car. The last time it happened it just appeared to reset itself after about an hour or so - so I'm still checking it from time to time.
The car: 996, 2003, C2, 16k miles, extended Porsche warranty. Any ideas what could be wrong - or should I have just locked the car after filling it up?

Richard_Hamilton · Jul 16, 2006

There is a TSB on this - If you want a copy of the whole thing, send me an email and I'll attach it to a reply.

Incorrect Fuel level Display In Instrument Cluster

Vehicle Type: 911 Carrera (996)

Model Year: As of '02 {2}

Concerns:

Information:

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.

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.

Guest · Jul 21, 2007

Hi Adrian I've got the same problem including it starting having just filled up with ron 95 (no other half in car tho'!). Was it a quick fix for your OPC?
best
Steve
996 C4S cab 2004

adrian996 · Jul 21, 2007

Hi Steve. I didn't take the car to OPC, it just fixed itself after stopping the car and leaving it for half an hour or so. I'm sure that the problem is related to the routing of the breather pipe for the tank. A few people have said that it's got a few twists and turns in it and that if the fuel level falls to a low level (circa 1/5th of a tank in my case) then it takes a while for the air pressure to sort itself out. If I were to run the fuel down to that level again now it would almost certainly happen again, I'm sure! I just try to avoid letting the level drop too low now, but it shouldn't happen, not on a car like this. Adrian.

Tool Pants · Jul 21, 2007

Was the engine running when you fueled up?

POR_NT · Jul 21, 2007

Had this happen a couple of times to me (my car is 2000 C4 cab).

I recall that on both occasions the other half was left in the car as I refuelled and the ignition was left on (so that she could continue listening to music).

A little disconcerting at first, so I can either just right it off as quirk, or just remember to remove the keys!

garyw · Jul 21, 2007

My 996 always did this on a splash and dash, however £40 would usually of been OK/borderline.

My 997 is exactly the same....[&:] I've learned to live with it now i'm aware of it..

garyw

Richard_Hamilton · Jul 21, 2007

The 996 C4 has a saddle tank, and a 'pocket' at the bottom. The level sensor cannot physically read the fuel in this pocket, and the computer calculates the level remaining. The volume of the pocket is 19 litres, so you have to put at least that amount in the tank before it reaches the level sensor, and the correct level is displayed. Hence, if you do a splash and dash, the level gauge will not show the extra fuel added.

delboy · Jul 22, 2007

This happened to me too about 6 months ago too. Put £20 of RON 95 in after "Consider refueling.........." warning. Didn't lock the car whilst paying. Drove off and 5 miles later, still showed the "Consider refueling.........."warning. Went back to the garage, rather unhappy and convinced the attendant that their pump may be faulty................ He called the Manager over and gave me another £20 from a different pump.

Needless to say, after reading this thread I feel a little guilty now.........only a little though!