WTF is wrong with my car?

[EL_Fairmont]

I have a MINT condition 1997 EL fairmont... with just on 112,000 kms on the clock.

FULLY serviced every ten thousand k's
The only previous owner... was some company in Burwood victoria.

The car drives like a dream... and is Brand new basically.


When i first got it... i drove it a bit hard... and got 16 litres per 100.

Now... i've driving MEGA CONSERVATIVELY and it still uses 15.5 litres per 100. - even on the highway....

The book says 13 !!!!!!

WTF is wrong ? I had it checked by ultratune and the dealer... they can't find anything wrong?

It's costing me a bloody MINT to run it.... any ideas ? - No gas is NOT an option.

well, id say just thrash it as it only use half a litre more :P

[snypereb]

Thats sounds a little out i think my eb runs about 12-13 per 100.

[InitialD]

Originally Posted by John_xr6

well, id say just thrash it as it only use half a litre more :P

hahaha thats my excuse and im sticking to it

[stockstandard]

There are so many things it could be: exhaust, gearbox/convertor, stuffed sensor... the list goes on. I would find a mecahnic who will spend the time sorting it out.

Are these numbers what the trip computer tells you? How many k's do you get out of a tank.

[Clarke AV]

Things it could be Your foot

[EL_Fairmont]

Things it could be Your foot

haha, NO WAY. I have DELIBERATELY avoided touching the accelerator.

Are these numbers what the trip computer tells you?

The trip computer tells me 15.5 litres per 100... and I have no idea the last time i had a full tank of petrol in it to measure it.

I'm going to look at the exhuast... although i couldn't find any holes in it last time...... say there were some, how bad could it be affecting it's fuel consumption....3 HOLE litres? i doubt it... but i hope so because a hole in the exhuast sounds a lot less expensive than a gearbox/convertor issue.

[JC]

Two things it could be - O2 (HEGO) sensor in the exhaust or faulty MAP sensor. Either one of these not working properly will make the car run rich. The MAP sensor is more likely, but the O2 is easier to diagnose (cos it's easier to get to). Disconnect the plug to the O2 sensor and start, then drive the car. If at idle there is no difference, then that's almost to be expected. If you give it a rev and it coughs, then the sensor is probably working OK. If when you drive it it bogs down when you put the boot in, then the sensor again would be OK. Basically, if it runs the same with the sensor connected or not, then the sensor is not working and needs replacing.

[Hunter]

My 96 EL GLi averages about 14 or so L per 100 kms... and I drive it pretty hard. I don't have a trip computer so I have to use manual calculations and estimations. Have you tried working it out yourself? Fill your tank at dawn, reset your trip meter, drive it till its nearing empty (say when the light comes on) and then fill up again at dawn the following day (fuel is denser when its colder). Find out how much fuel you actually used (by taking into account how much was left in the tank and how big your tank is, should be 68 litres iirc). Then do the math and work out how much it averaged. I'd do that in case your trip computer is a bit bodgy.

Check your tyre pressure, auto fluid levels, etc. Heaps of things! Also, check the condition of the plugs... if its running overly rich then they may be very dark ie covered in carbon deposits. But then if you took it to ultratune and a dealer, chances are they have tested all of the relevant parts and any serious issue would've made itself quite apparent.

One last thing, the mileage that the manufacturer quote and the actual figures are often very different. 15L/100 is not something I would think is unusual, particularly for a Fairmont which is somewhat heavier than the regular Falcon.

[EL_Fairmont]

I've also noticed it's running slightly rough @ idle...

I've just had ultratune do the 110 k service on it.. replacing the air filter ... and all the other regular service woo-haa.

So you think it's one of the sensors? Well that's a start... i'll tell the guys that when i take it down to a (different) mechanic.

[stockstandard]

Originally Posted by EL_Fairmont

I'm going to look at the exhuast... although i couldn't find any holes in it last time...... say there were some, how bad could it be affecting it's fuel consumption....3 HOLE litres? i doubt it... but i hope so because a hole in the exhuast sounds a lot less expensive than a gearbox/convertor issue.

Its not holes in the exhaust you have to worry about - you would hear them. Cat's and mufflers can rust out, get blocked up, or the internals can fall apart. Its these sorts of things that create restrictions in the exhaust system and hurt fuel economy. Its only one of many possible causes though.

[Walkinshaw]

whens the last time you reset your trip computer?

[EL_Fairmont]

The last time i filled it up and reset the trip meter to zero... would of been weeks ago and i can't remember the figures.

WHAT I DO remember is that i got 230 kms on just over half a tank (highway trip to phillip island.)... so using the laws of logic that'd mean it'd get 430 ks or so (minus 30 because it was over half) ... on a full tank .. but... it's still using far too much driving around (CONSERVATIVELY) in the day to day traffic.

Chr1st... i'll have it at the mechanics at 8 am tomorrow morning... i'm worried now....

[Hunter]

What mileage do you do on the first 1/4 tank? I can get anywhere between 120 and 180 on the first quarter tank of the gauge...

[EL_Fairmont]

It seems... to be... the lower the gauge gets, the more petrol it uses....and no, I don't have the A/C stuck on either!

[eb91xr6]

fill your car up and cheek the km done of a full tank and do your maths and get the corrct number the trip computer is and is very inaccuret

[EL_Fairmont]

Well, thanks guys.. i've got a bit more info now...

I'll drive it till it's dry... and do the maths... and if there's anything sus i'll put it into the mechanic.

Other than the petrol issue....it's a brilliant car.

[BELTA]

there is proberly nothing wrong with it

[Fairlane]

Sounds like a shonky Trip computer to me, Id do what the others are saying and drive it until its nearly empty and then crunch the figures.

[niko]

my bro's ef fairmont + full exhaust + wade 112 + auto gets 8-10 on freeway and 13-20+ ocal driving

[ilsautomotive]

The car should be warming up to just under half way. If not it should be pretty easy to diagnose.