Au Falcon I6 doing 16L/100km, Whats wrong?

[aufalcon001]

hey my falcon it terrable on petral, i dont lead foot it every where but but it still uses a ton of fuel could there be somthing wrong with my car?

[chrispie123]

does the heater get hot?

[aufalcon001]

yeh the heaters hot

[4.0i_SiX]

It could be a number of things, Oxygen sensor ever been replaced? I would start by putting it on a scan tool and see what codes it brings up

[aufalcon001]

i was thinking it could be the oxygen sensor. Im not sure if its ever been replaced iv only had the car for about 6 mounths and the guy who had it before me trashed it so i dont even have a log book.

[Falc'man]

Welcome to AFF.

The general idea is you should get it serviced regularly, but assuming you already do this give us an idea of what kind of traveling you do, as well as the average km/h (if trip computer shows this).

What did it used to do, and have there been any changes to the car since?

Oxy sensors may need checking? As mentioned above.
Do you have an aftermarket thermostat?
Are you using cheap fuel?
Is your car dual fuel?

[aufalcon001]

im not sure if its been replaced i havent had the car long and i dont have a log book

[aufalcon001]

my car isnt duel fuel, i use 95 octaine sometimes 98 and for the thermostat i wouldnt know

i generaly drive about half on the motorway and half around the city and as i said above i dont hammer it

[smoo]

where does your temp gague sit, should be around N or O.

[aufalcon001]

it sits somewhere around there. It runs great apart from that if i cant sort it out im going to have to sell it for somthing better in petral:(

[GS608]

theres a few things that could be causing you grief..
when was it last serviced?
as above the oxy sensor
what about plugs and leads?
fuel filter?
doubt the gearbox would have been flushed so I'd get that done too.

If it has been thrashed as you say then I'd have a look over all those parts (or get a mechanic to do it)

[aufalcon001]

yeh im going to get it serviced really soon. also my revvs drop really low and it almost stalls after every time i disconnect my battery but it fixes its self after a little while could that have anythitng to do with it?

[747jet]

check you coolant temp sender it could be sending singal to the ecu telling its runnig cold. there a filter in the fuel pressure reglator that blocks up that need to be replaced can not been cleaned. a blocked filter in the fuel pump in tank can cause that as well. have a look at ther 1 st

[JC]

Could also be a blocked cat - car uses extra fuel to get going etc.

For $70 odd, i'd start by replacing the O2 sensor - it is the most likely cause of rich running.

Also, there;s no point using 95 or 98 fuel on these things, they are built to run on 91 and will not make any additional power or economy on 95 or 98 (though these fuels do contain additives that keep the fuel system clean, so there is that benefit, but using on tank of premium to 3 of ULP is all that's needed to keep fuel system clean), despite urban myths to the contrary.

[Mr Hardware]

Originally Posted by OP

Au Falcon I6 doing 16L/100km, Whats wrong?

I'm gonna put it to you all that this is what's wrong:
Absolutely Nothing.

When I had my AU1 i used to do about half motorway/half city and i'd see 15L/100klms - and there wasn't anything wrong with it. I didn't hammer it but i expected 6-cyl performance from it, and that would result in that sort of economy.

[mickyyyy]

Originally Posted by Mr Hardware

I'm gonna put it to you all that this is what's wrong:
Absolutely Nothing.

hahahah love it

How many kms on it???

[JC]

Originally Posted by Mr Hardware

I'm gonna put it to you all that this is what's wrong:
Absolutely Nothing.

LOL - I was also thinking that, but given the mix of city/hwy driving, i'd be looking for closer to 14l/100km. The 2l/100km difference equates to around $10 a tank, so it only takes 7 tanks to recoup the cost of an O2 sensor - IF that fixes it. If it doesn't fix it, then the choice is to put up with an extra 2l/100km usage, or spend money finding the problem that may take 30+ tanks to recoup.

[sleeper393]

Originally Posted by 747jet

check you coolant temp sender it could be sending singal to the ecu telling its runnig cold. there a filter in the fuel pressure reglator that blocks up that need to be replaced can not been cleaned. a blocked filter in the fuel pump in tank can cause that as well. have a look at ther 1 st

if the coolant temp sensor is bung will it alter the temp gauge reading, or can it still read normal.

[Mechan1k]

If the Cylinder Head Temp sender is bung ... you'd have a hell of a lot more issues than just high fuel economy.

First thing ... replace the O2 (HEGO) Sensor ... I got mine for $50 off ebay (was a genuine Ford part as well) ... and run the vehicle and test that out.

Then go from there.

[Jack91]

Those arent really bad numbers, only way youll really better it is to change your driving style considerably, just because you dont lead foot it doesnt mean you are "driving efficiently"
Everybody that suggests the o2 sensor, that was one of the first things I did and it made NO DIFFERENCE. Honestly if it was gone and needed doing itd be more noticeable than pretty ordinary figures anyway. Biggest waste of money Ive ever spent on a car was an $80 o2 sensor

[Mechan1k]

I found I had to do the O2 sensor as mine went from 14-5L/100km to 20L/100km (factory LPG) just under normal driving conditions. So when they do go ... it is really noticable as DAVOXR mentioned.

Also he is right as well with driving style ... the best way I have found is to look well ahead ... and keep a constant flowing momentum through traffic if you can ... with little stopping if possible. Gentle easing throttle inputs are key as well. Also I found anything 60km/h and under ... I found i had better economy dropped back into 3rd out of D as well (it reduced the amount of gear hunting in the auto).

[grandpa_spec_F6]

If it was the VCT motor I'd say thats about normal, the I6 should be a little under, depends on how / where you drive. I do mostly city km's so 400k's a tank is about the max I expect

[GS608]

Also depends on where your driving, for example city driving in Brisbane or Sydney will suck more fuel than city driving on the Gold Coast (**** loads less traffic lights)

I do basically 95% city driving and am on 14.2L/100km by the trip computer.

[smoo]

Originally Posted by DAVO_XR

Those arent really bad numbers, only way youll really better it is to change your driving style considerably, just because you dont lead foot it doesnt mean you are "driving efficiently"
Everybody that suggests the o2 sensor, that was one of the first things I did and it made NO DIFFERENCE. Honestly if it was gone and needed doing itd be more noticeable than pretty ordinary figures anyway. Biggest waste of money Ive ever spent on a car was an $80 o2 sensor

Yep you'll notice if the O2 sensor has had it... my Fairlane mileage was halved down to 350k/tank highway. Too bad for me the cheapest one over here was $150 trade price, had to get one off Aussie ebay for 60 bux.
If people think 16l/100km is the norm they need to take a look at their driving style, I consistently manage 10 to 11 l/100km 50/50 hwy/city driving.

[4.0i_SiX]

If you have ever used a scan tool you will know that the o2 sensor can be slightly out of range ( voltage reading ) and this can and will have an effect on economy. I wouldnt just go change it without putting it on the scanner first though. Potential waste of money


However, I'd ONLY be doing this IF, the car has been serviced with the following items recently checked or replaced.
Air filter
Fuel filter
Gauze filter in fuel pressure regulator ( generally causes more of a poor idle )
Thermostat ( not jammed open taking longer to warm up/richer mix? )

Once that stuff has been done, put it on the scanner. If all is well then I would be doing the injectors

[Mr Hardware]

sometimes it'd be nice if the OP cared for their thread for longer than a day or reported back whether stuff worked or not...

[mik]

Originally Posted by aufalcon001

hey my falcon it terrable on petral, i dont lead foot it every where but but it still uses a ton of fuel could there be somthing wrong with my car?

so how much do you lead foot it?

[Auturbo6]

My apprentice returned from the servo today, and in horror proclaimed; I just saw some moron in a WRX filling his car with 91 E10, and next to him another moron filling his BA XR8 with the same 91 E10. Being a mechanics, this amuses us immencly, these people will turn up to their prefered mechanic and complain about poor idle, poor response, poor fuel economy, poor starting etc and the poor blokes won't be able to fix it. Change to 98 premium, for a few tanks and re-evaluate. (And now im going to get a bunch of reply's about the price of premium compared to horse #@#) Cars are people too! So feed them well........... Or buy a prius.

[azza11]

Mine runs a lot better on regular ULP. The lower end stuff is really noticeable from the smell from the zaust to how long my DTE starts to go down. Mine is in a very good state of tune. Also some servo operators do drop a shandy from time to time so go elsewhere and see or do the o2 sensor.

AZZA

[azza11]

Originally Posted by Auturbo6

My apprentice returned from the servo today, and in horror proclaimed; I just saw some moron in a WRX filling his car with 91 E10, and next to him another moron filling his BA XR8 with the same 91 E10. Being a mechanics, this amuses us immencly, these people will turn up to their prefered mechanic and complain about poor idle, poor response, poor fuel economy, poor starting etc and the poor blokes won't be able to fix it. Change to 98 premium, for a few tanks and re-evaluate. (And now im going to get a bunch of reply's about the price of premium compared to horse #@#) Cars are people too! So feed them well........... Or buy a prius.

It makes sense to do premium. Seeing most mechanics will put a diagnostic tool on and charge for a full tune or more. (only some) Reset the computer as well can help.

AZZA