98 3L 165k and its starting to use more and more fuel and im driving the same way did 20km in town and 90km on the hiway and and it used about $20 worth any ideas?

Doesn't sound very high? 120km for 14ish L ? That's normal.
When was the last service? If it has been a while you might want to change air filter/oil etc as it could be degrading economy.

Very normal, start getting used to it :P

lol 80 Km for $20 of fuel out of my gen 2 V6 auto if I use it for short trips only.

It used to go twice as far on $20 when petrol was half the price. Funny, that.

5k since last service. can u wash the air filter or have to get it replaced?

Unless its a K&N style / rechargeable filter - then no you cant wash it out.

If desperate - you can always shake it out a bit, but dont puncture the filter... or it wont be able to do its filtering job

They're not that expensive to replace either

i had a look looks like a part of the air box? or dose it clip out?

Flip the 2 clips up and lift the filter out. The outside of the filter is part of the case when it is all together.

98 3L 165k and its starting to use more and more fuel and im driving the same way did 20km in town and 90km on the hiway and and it used about $20 worth any ideas?

If it's showing signs of running rich, you might want to look into replacing the oxygen sensor - 160000km is about their rated life. The symptoms of a failing O2 sensor are usually much more noticeable with highway driving.

If it's showing signs of running rich, you might want to look into replacing the oxygen sensor - 160000km is about their rated life. The symptoms of a failing O2 sensor are usually much more noticeable with highway driving.

how much are they to replace?

They are usually under $80, however I'd be looking for other signs as well as perceived increase on fuel usage such as Increased tailpipe emissions, Hesitation on acceleration, Stalling, Rough idling - one or more of these symptoms usually accompanies increased fuel usage when the sensor fails.
If the sensor is going bad it will usually have a black sooty appearance on it's nose as well.

its has a rough idle and and a bit of Hesitation on acceleration when cold. but dose not stall

Possibly it just needs new plugs and check the leads and distributor cap as these can also cause the rough idle and hesitation - I like to check more simple items first. Has the throttle body been cleaned lately?

im not sure is it hard to clean yourself

and what would be making it use so much fuel?

Intake temp sensor, MAF sensor, bad o2 sensors... all easy things to clean (and if need be, to replace).

Intake temp sensor, MAF sensor, bad o2 sensors... all easy things to clean (and if need be, to replace).

and how do i find and clean them?

If today wasn't so crappy I'd be out making a guide with plenty of photos, as my TE needs to be done.

Rather than the $25 can of "MAF Cleaner" from Supercheap, I bought "Electronics Cleaning Solvent spray" from Jaycar for $11 (its in a green bottle), its safe and fully-evaporates - unlike Carby Cleaner - so it doesn't leave behind a stickiness that could impede the sensors or cause more junk to stick to them. I did my Commodore's MAF, intake temp sensor, Throttle Body and Idle Air Control motor, as I was getting increased fuel consumption and unstable idle when turning/braking at low speed. The only thing I haven't checked over is the o2 sensors, but overall it feels a tad better already - lack of muck in the intake has to have a positive effect !!

If today wasn't so crappy I'd be out making a guide with plenty of photos, as my TE needs to be done.

Rather than the $25 can of "MAF Cleaner" from Supercheap, I bought "Electronics Cleaning Solvent spray" from Jaycar for $11 (its in a green bottle), its safe and fully-evaporates - !!

I used the MAF cleaner on my old commodore as well and felt crook from the fumes so I'll get some of the Jaycar stuff for my Magna....good idea wackywheelz..

cleaned the TB just then afair bit of shit came out and seems to be runing smother. repco wont's $140 for a new o2 sensor is that bad or?

Well..

my VRX has the same issues, 3.5ltr 5 speed

i get like 200kms from $40 its not good at all..worse then my v6 commodore was!

what can i do..i was considering gas? but now im thinking sell it and buy a 4cyl 5 speed

is it worth a try getin the 02 done?

Well..

my VRX has the same issues, 3.5ltr 5 speed

i get like 200kms from $40 its not good at all..worse then my v6 commodore was!

what can i do..i was considering gas? but now im thinking sell it and buy a 4cyl 5 speed

I'd be checking the instant fuel consumption when you're cruising on the freeway. If your instant consumption on a dead straight and FLAT bit of road is well above 9L/100km at 100km/h then it's worth considering an O2 sensor replacement.

As well as my Magna, I have a 2007 XR6 turbo, and I get about 9-10L/100km when cruising at 100km/h on flat roads. The magna should beat that (even considering the ridiculously awesome 6-speed auto in the Falcon).

Thats if he has an LCD fuel readout (which is mostly in later/upper-spec models). None of my cars do, I rely on this fuel usage calculator (http://motormouth.com.au/myvehicle/consumptioncalculator.aspx) to see what mine is doing.

My TE (3L) gets down to 9.5L/100kms on the highway (once down to 8.8) and 12.3L/100kms around town. From a $50 fill (37.5 litres), thats between 300-380km range.

When I do my cleaning guide, I'll include o2 sensor removal/checking/replacement.

When talking fuel economy never say I get x amount of km to x amount of dollars, you need to keep track of how many litres you put in the tank. You would be surprised how many people come into the dealer complaining of "poor" fuel consumpsion when the price of fuel increases.

cleaned the TB just then afair bit of shit came out and seems to be runing smother. repco wont's $140 for a new o2 sensor is that bad or?

If it's running smoother then maybe it's using less fuel so why not wait and see if it still is chewing fuel.

You can spend a lot of money replacing items trying to obtain maximum fuel economy.....quite often little if no improvement occurs, but we try and tell ourselves it was money well spent...............

Can i pull the o2 out and and check it ? And put it back in or dose it need to be replaced?

Well..

my VRX has the same issues, 3.5ltr 5 speed

i get like 200kms from $40 its not good at all..worse then my v6 commodore was!

what can i do..i was considering gas? but now im thinking sell it and buy a 4cyl 5 speed
if that's about 30L of fuel, that's about 15L/100k's which if your doing stop start city driving is around about right..

When talking fuel economy never say I get x amount of km to x amount of dollars, you need to keep track of how many litres you put in the tank. You would be surprised how many people come into the dealer complaining of "poor" fuel consumpsion when the price of fuel increases.

Exactly right. When I had Sigmas years ago the cars cost me 10 cents per km in fuel, the Magna is now up to 25 cents per km. So does the Magna have poor fuel economy compared to the Sigmas? Nope, the cost of fuel has gone up. Blame the fuel companies, taxes etc, not the car.

Poms pay roughly twice as much for fuel, Yanks half as much. Been like that for decades.
Currently US $2.97 a gallon (=4 L) in Albuquerque, New Mexico. London is 132.9 p per liter. (= AU $2.11 /L)

Can i pull the o2 out and and check it ? And put it back in or dose it need to be replaced?

You can pull them out. If they are coated with black carbon, you know the car is running rich. They should have a thin gray coat on them if running correctly.

So if its runing rich means the need to be replaced? How hard is it to replace them

Take the car for a nice long country drive before you pull it out to give it a chance to get up to working temperature. You need to unplug it from inside the car before you get under to spanner it off the exhaust manifold. Replacement and inspection are the same job really.

Yes, take it for a nice long country drive so you get it all hot so you both burn the crap out of your hands and also while you are at it, you wreck the engine pipe when the hot thread binds

In general, an oxy sensor even if it tests reasonable if done more that 100k is stuffed, they get lazy, like people I guess, while they will generally read close, the time they take to adjust is far too long

They are not expensive, they are in my store and they are not hard to change, or you can get them cheaper in the us, despite prob 100 freight lol

Yes, take it for a nice long country drive so you get it all hot so you both burn the crap out of your hands and also while you are at it, you wreck the engine pipe when the hot thread binds



Oh that's just silly! A smart person would let it cool down a bit first! lol

Diamante 2001 3.5L oxygen sensor
BOSCH Part # 13412 OE Type - Exact Fit
Located in rear manifold / exhaust pipe; 4 Wire; Heated; OE Type - Exact Fit - Downstream Sensor, AU $60 + AU $26 postage.

(Not quite the $100 postage Mal suggests. But buy one from him anyway, and keep your money in Australia. lol)

Something to read . . . . .
http://www.boschautoparts.com/Technical%20Resources/Oxygen%20Sensors/BoschTips_faultyO2.pdf

Oh that's just silly! A smart person would let it cool down a bit first! lol

Diamante 2001 3.5L oxygen sensor
BOSCH Part # 13412 OE Type - Exact Fit
Located in rear manifold / exhaust pipe; 4 Wire; Heated; OE Type - Exact Fit - Downstream Sensor, AU $60 + AU $26 postage.

(Not quite the $100 postage Mal suggests. But buy one from him anyway, and keep your money in Australia. lol)

Something to read . . . . .
http://www.boschautoparts.com/Technical%20Resources/Oxygen%20Sensors/BoschTips_faultyO2.pdf

Why spend more on the same product? That's actually very cheap....I would of gotten mine from rockauto back then if I had known about it.
www.rockauto.com, get on it.

Most workshop manuals suggest removing the oxygen sensor from a warm/hot/running engine to allow them to unscrew easily....normally you just crack the thread when hot and wait till it cools bit to fully unscrew. This is from a home DIY persons perspective who has plenty of time to devote to this job.