Poor Fuel Consumption in Bora Please Read

**h3ktik** · 11-06-2012, 08:48 PM

2002 Bora 2.0L
177k kms

- Very bad fuel economy.
- Took into mechanic. Car had not been scanned for years.

These errors came up:

16518 bi-si no activity
16500 coolant temp plausibility
17536 long term fuel trim multi bank 1 system too lean
16555 bi fuel system too lean
17990 idle adaption at limit
17978 engine control unit blocked
16684 missfire detected
16688 cyl 4 missfire detected

Apparently after the codes were cleared, none came back after a test drive.

However, I have noticed no improvement in the fuel economy.

I finally bothered to fill up the whole tank. I first noticed the fuel indicator only went 3/4 of the way!
Anyways, the car chewed up petrol like anything, it hits empty, I'm thinking ive only driven 350ish kms the indicator is prob dodgy, but when I filled up I was able to put in 53litres which is pretty much a whole tank.

So I got 350km (a lot of highway kms) from a full tank!

Any ideas guys?

I havnt had the fuel filter changed the couple years that I have had it. MAF?
I really dont trust any mechanics here in Canberra.

**dylan8** · 11-06-2012, 09:13 PM

there is a vw mechanics up there (iv had a blank on their name). I believe they know their stuff.
has been serviced as per its schedule?
does it sound like its misfiring?
does it run at temperature?
does it blow fuel out the exhaust?
does it feel responsive under acceleration?

**tek199** · 11-06-2012, 09:15 PM

drive the car normally for few days and scan for codes again.
(get OBD2 scanner and a cable and check the codes yourself)

air filter, fuel filter, dirty injectors, faulty spark plug leads, faulty spark plugs, faulty ignition coil, blocked cat converter, poor compression .. etc etc normal culprits.

**kapowww** · 11-06-2012, 11:49 PM

If it hasn't been scanned for a couple of years, fuel filter hasn't been changed in a while and you don't trust mechanics... has it been given a decent service recently?

If not it should be top priority not just for fuel economy but preventative measures.

**brad** · 12-06-2012, 08:29 AM

Go to one of these:

Welcome to Canberra VW Centre - your Volkswagen specialists in the ACT.

Canberra VW Center Tuggeranong

**h3ktik** · 12-06-2012, 10:39 PM

thanks for the replies.

I should add, very strong smell from exhaust, burnt fuel or something.

It has been serviced every 10,000 kms, but just oil service. Also mechanics never brought up anything of concern.
Basically I dont want to spend much money on this at all, I just use it as a daily, so im gonna take it to a regular mechanic before for specialists first. I've booked it in at a mechanic so he can go over it and look into things which might be causing this.

**h100vw** · 13-06-2012, 08:23 AM

Originally Posted by h3ktik

thanks for the replies.

I should add, very strong smell from exhaust, burnt fuel or something.

It has been serviced every 10,000 kms, but just oil service. Also mechanics never brought up anything of concern.
Basically I dont want to spend much money on this at all, I just use it as a daily, so im gonna take it to a regular mechanic before for specialists first. I've booked it in at a mechanic so he can go over it and look into things which might be causing this.

Specialist doesn't necessarily mean expensive. You could easily spend more money at a another mechanics, while they work out what is wrong. The specialist would most likely spend less time on the diagnosis.

Have you filled up the tank to see how much juice it really used? You can't trust the gauge obviously, if it never went to full.

Water temp sensors are cheap and a fuel filter costs nothing. Lambda probes cause high fuel consumption when they are toasted.

Gavin

**brad** · 13-06-2012, 09:50 AM

Specialist will be cheaper in the long run.

I could do all my servicing myself but I still send my car to a specialist.

**dylan8** · 13-06-2012, 12:33 PM

as above, dont try to be cheap by sending it to a average mechanics, itll cost you more in the long run (non genuine parts, more time figuring out whats wrong etc)
do have to spend money on these cars every now and again if you want it to last. id rather replace all the sensors etc or a few hundred $ then end up with a car that cant go 300KM on a tank or ends up doing engine damage.