S3 - Horrific & hideous fuel consumption.

[Schlaag]

Hello all

Our S3 has developed a terrible thirst! It's quite ridiculous!

A simple 4 mile journey from our house to the train station knocks 15 miles minimum off the fuel computer. Its almost as if there is a leak! (there isn't)

The engine is standard map wise. Just a Badger TIP and a cone in the original airbox. and a Forge recirc BOV.

Is there anything I can check that may have gone tits up? Car passed the MOT fine the other week so emissions are in check.

The live fuel computer drops to 8mpg the odd time when taking off in 1st and 2nd... and its rarely above 20 when on a drive!

Any standard checks? It would be cheaper to run a Range Rover!

thanks

 

[Gary_808]

Check for split hoses,
How quickly does it get up to temp? For vag com?

Mine was terrible on fuel,
Swapped the cts got slightly better then realised the thermostat was stuck open, swapped that got better,
Then fitted a catch can to do away with all the pipe work under the inlet as it was knackered, now it's much better on fuel, on a run it has hit 38-40mpg and round town averages 30mpg,
Does depend alot on your driving style as well.

 

[Welly]

Bit of a minefield this as it could be many things... Other possibles are MAF, dodgy lambda sensor, and as was mentioned before, the thermostat - but if it's the stat then you should see the car not getting up to temp on the dash.

 

[kwistof]

Hook it up to VCDS mate and take some logs if you can't see any split hoses/pipes or anything else obvious.

My MAF and Lambda sensor along with a split hose caused me issues :-\

After replacing those I was able to get back into averaging around early 30mpgs.


Just a side note- welcome back Welly.....and nice car btw :icon_thumright:

You still got that A3 ebay special car you was doing up?

 

[Crazypete00]

thermostat on mine was knackered changed that and it did get alot better. i probably get about 25mpg or about 30mpg on a good run.

 

[<tuffty/>]

Any fault codes? what year/engine code is the car?

<tuffty/>

 

[Welly]

Just a side note- welcome back Welly.....and nice car btw :icon_thumright:

You still got that A3 ebay special car you was doing up?

I dip in and out lol - quiet day today so thought I'd pop in...

No mate, I got it running and sold it. Basically my old man told me either I get shot or he was going to scrap it as he was fed up with it being on his drive. Car was sold for the engine to go into a Corrado as far as I know. Ran sweet as a nut .

Sorry for the thread hijack!

 

[:: blade ::]

mines quite bad on fuel, putting £20 of fuel in every 2 days, its killing me, on the average mpg on the dash it goes between 25-30mpg but i know there not that accurate, but thats around town driving like a granny too, so it never goes on boost properly as it just kills the fuel, worked it out when i filled the tank last month it lasted just under a week and got about 380miles which i think is normal with these cars. that was mixed motorway and town driving, again driving like a granny too

 

[shan00ble]

Mine is terrible I got 350 km on a full tank. I cant work out what is causing the issue. I do however erive a shortbditance to work everyday and by the time I get to work the needle is still on cold.

 

[dannyh]

I always look at the HUD, i see 30 round town, i would check the thermostat and temp sender, what temp does yur car sit at when hot?? if its slightly too hot or cold it can burn more fuel

 

[Schlaag]

Thanks guys.

Thermostat is new, I replaced a few months ago (that was a nice job with big hands!) So temp rises to midway pretty quickly and stays there.

Will try and get a scan, its never been scanned in the few years I've had it. It's a 51 plate car. AGU, perhaps AMK I think, my memory is terrible.

 

[kwistof]

AGU, perhaps AMK I think, my memory is terrible.

Wouldn't be an AGU if it's an S3 engine fella as the AGU has a K03 IIRC.

Your sig could give you a reminder ;-)

 

[Darren4]

Long shot but maybe the fuel pumps getting old and tired? Had to replace mine before my remap as mine was on its way out, fuel increased a good bit.

 

[shan00ble]

How long on average does it take for the car to reach normal operating temperature.

 

[:: blade ::]

mine takes about 15 20mins to get to temp, mines just got 83 miles to £20 of shells finest which is at 136.9 here

 

[JimS3]

mine takes about 15 20mins to get to temp, mines just got 83 miles to £20 of shells finest which is at 136.9 here

That's way too long to warm up, sounds like your thermostat is stuck open.

 

[:: blade ::]

how long should it take to warm up?

 

[Gary_808]

I have a 3.6mile 5minute drive to work, my cars warm (90 on the gauge) before half way. All dual carriage way.

 

[:: blade ::]

will give it a whirl on monday as i dont usually drive it during the week as the other half uses it for work,

 

[moisty]

Maybe a long shot but try disconnecting the battery. After replacing my alternator my mpg went up a fair bit. Someone on here told me that it maybe due to faults getting cleared when battery was disconnected . I've just done approx 380 miles today and have just shy of quarter of a tank left.

Hope it helps

Cheers

 

[:: blade ::]

Timed my car today and it takes 10mins to get to temp on the gauge. 5mins for the gauge to move

 

[Joshstan]

For what it costs just go and get a thermostat it's fairly fiddly but do-able my mpg was shocking and temps took ages to rise then new stat in and all was well (and if the thermostat isn't the problem at least it's one you won't have to worry about in future)