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My fuel guage is a Liar

a996with2turbos

New member
Joined
8 Feb 2013
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27
Petrol light came on the other day and dash reads 64Km till empty, pulled into the Gas station and put 40bucks in her, petrol light is still on, petrol gauge needle has not moved a millimetre and dash still says only 64Km till empty? A 45 minute drive home and still same result, anyone had this problem?
 
Yes, relatively common.

A search will find a few threads on it.

Dont worry about it.

It will be an air lock that will clear after a bit.
 
PeterS said:
Yes, relatively common.

A search will find a few threads on it.

Dont worry about it.

It will be an air lock that will clear after a bit.

Caused by the bifurcated shape of the tank on 4WD 996/7 models in fact, not an air lock.
It will not clear itself until the tank content is increased to about 20 litres.

PS: On reflection, how many litres/gallons did the 40 bucks (US$?) buy?
In the US that would have been more than the 20 litres necessary to allow the "real" tank gauge to start working again.
 
Red993C4 said:
PeterS said:
Yes, relatively common.

A search will find a few threads on it.

Dont worry about it.

It will be an air lock that will clear after a bit.

Caused by the bifurcated shape of the tank on 4WD 996/7 models in fact, not an air lock.
It will not clear itself until the tank content is increased to about 20 litres.

PS: On reflection, how many litres/gallons did the 40 bucks (US$?) buy?
In the US that would have been more than the 20 litres necessary to allow the "real" tank gauge to start working again.

Thanks for the info guys, my fault for being a cheap ass, should have put more gas in her, just had 40bucks cash on me so used that.

PS: Stuff all to be honest, it gave me about another 22 litres or around there somehere, next time ill know better
 
Mine does it...... when light is on I have to fill it up completely. If I put as an example 20 litres gauge will still be in empty zone and light will be on.
 
After reading about this little querk when I got the car I have just bitten the bullet and always filled it right up. Feel safer that way :)
 
Normal (for an AWD chassis).

The critical figure is 19 litres.

You have an AWD chassis, so you have a split fuel tank (ie "separate" sections, rather than leaking!)

The AWD models (so C4, Turbo etc) have additional driveshafts to and at the front (obviously), but this poses problems for the original position/size of the fuel tank.

So AWD models have a reshaped tank, to straddle the driveline and new chassis strengthening structures and driveshaft mountings etc.

The fuel gauge technically only operates above the "flat" of the tank, any fuel level below this is "guessed" by a fuel tank algorithm and sent to the electronic analogue display on the dash.

This means if you are empty and add only enough to fill the lower section of the tank, the sensor is still dry and the gauge won't move (ie under-reads fuel volume)

This might sound stupid, but it is preferable to having the sensor in the base of the tank and over-reading and hence you thinking you have more fuel.

Once enough fuel is added to fill the lower section (ie up to the "flat") the sensor is "wet" and the gauge reads as normal (ie a measure of the entire tank).

This "flat" volume is usually about 1/4 tank (below 19 litres the system actually guesses your remaining fuel from fuelling data, only once it is refilled above this level again is the alogorithm reset and continuous reading handed back to the sensor).

Note: in the diagrams below the "2WD" and "AWD" refer to chassis type, this means as GT3/G2T models use AWD chassis and hence use AWD tanks.

996_fuel_tanks_209.jpg
 
When I posted my reply, I assumed the $40 would've filled the car up. There is another thread and diagram somwhere about a kinked air pipe, I think it is a TSB.

:D

What country are you in?

You need petrol (so not USA, or at least not an American, as speak English), pulled into a gas station (so could be USA), but talk in Km, not miles.

:?:

:dont know:
 
Oz

1L PULP98 = AUD1.40-1.90 (depending on location)
 
GT4 said:
Note: in the diagrams below the "2WD" and "AWD" refer to chassis type, this means as GT3/G2T models use AWD chassis and hence use AWD tanks.

996_fuel_tanks_209.jpg

Except for RoW LHD GT3/GT2 models, which take advantage of the lack of front wheel drive to use a big, beautiful 90 litre fuel tank to give them a better range.
 
True, and for the last three years that post has been wheeled out, I still haven't added the RHD caveat.

Always leave something on the table for the next guy...
 

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