Poor Fuel Consumption

[Monzta]

The fuel consumption of my A4 1.9 TDI PD 130 around town is pretty poor, £20 of diesel gives me 70 miles if I take it easy. Most of my driving is around town usually from cold start (school run, picking up from my customers in town and the odd run out to surrounding villages). I know town driving is the worst for economy but my trip computer is showing approx 23mpg (sometimes worse). I was expecting to be getting more.

I did a run out at the weekend of about 160 miles of A-road and dual carriageway and by the time I got home I was up to 47mpg ... that's more like it. But this week it's back to low 20s around town again. My car does smell quite 'fumey' at times like it's not in tune or there's an exhaust leak somewhere.

I've got no CEL or codes coming up on VCDS. Could this be down to something as simple as the EGR system needing a good clean out?

Car is a 1.9 TDI PD 130 AVF with multitronic and I never drive it hard.

 

[Monzta]

Just to add that it had a full service in the summer.

 

[joinerman]

Quattro or fwd ?

 

[Mike B]

Being an auto I think it may be normal.I have a 2.5 Quattro auto and there is a big difference in local and long run consumption.I have had the manual version which is better cos you can keep in higher gear if you want to whereas the auto is always ready to rev.The 2.5 will get close to 40 on a steady long run so maybe the 1.9 should be better than your 47.Maybe some injector cleaner would help.I also use V Power which I think can pay for itself in improved all round performance.Is it due a gearbox service?new ATF might help

 

[Monzta]

Quattro or fwd ?

It's FWD @joinerman

 

[Monzta]

Being an auto I think it may be normal.I have a 2.5 Quattro auto and there is a big difference in local and long run consumption.I have had the manual version which is better cos you can keep in higher gear if you want to whereas the auto is always ready to rev.The 2.5 will get close to 40 on a steady long run so maybe the 1.9 should be better than your 47.Maybe some injector cleaner would help.I also use V Power which I think can pay for itself in improved all round performance.Is it due a gearbox service?new ATF might help

The car came with no service history so I don't know when the gearbox last had new fluid. I want to get it done but at £300 it'll have to wait until the New Year.

I had hoped to be seeing 30+ mpg around town and approx 50 on long runs. The fumey smell is quite strong, like it's running rich. Other than that it runs nicely. I was wondering if a clogged EGR system could lead to this.

 

[quattrogone]

Worst kind of driving for any car, my 1.8t has got better recently in that I'll achieve 34-35mpg on the main roads but as soon as I hit town or any "nipping out just up the road" in it it I'll see it plummet to 23mpg easily...

 

[Mike B]

£300 is nearly double what I paid Audi 3 years ago.If you have no records that's the first thing I would do on a multi

 

[stevey83]

Where are you Monzta? I paid £169 for my transmission fluid change by an indi not long ago.

 

[Monzta]

Where are you Monzta? I paid £169 for my transmission fluid change by an indi not long ago.

Is your a Multitronic (CVT) 'box Steve?

I live on the Dorset/Somerset border near Yeovil. I was quoted £280 incl VAT by an indie. I'm guessing my local Audi dealer would be even more.

 

[Monzta]

£300 is nearly double what I paid Audi 3 years ago.If you have no records that's the first thing I would do on a multi

Yeah, I really do need to get the 'box checked out and serviced before I spend any more on the car. It has a slight judder just as you come to a stop. Nothing dramatic but there nonetheless.

 

[Monzta]

Worst kind of driving for any car, my 1.8t has got better recently in that I'll achieve 34-35mpg on the main roads but as soon as I hit town or any "nipping out just up the road" in it it I'll see it plummet to 23mpg easily...

From what I've read I should be getting 30+ around town though. My wife's 2.2 TDI X-Trail is getting better mileage than mine right now.

 

[boffin486]

Hiya Monza - I seriously recommend trying out FuelTone diesel additive - I had unbelievably good results with it when I used it on my dads Passat (TDi 130 engine). It went from smoking a lot to almost clean running - in fact, when I took it for it's MOT, it got an almost perfect emission figure - easily rivalling new cars! I use it on the B6 as well (same engine).
Heres a link:
https://www.ebay.co.uk/itm/Fueltone...196419?hash=item56c52c3603:g:Z-MAAOSwEiJc5Q3u

 

[stevey83]

Is your a Multitronic (CVT) 'box Steve?

I live on the Dorset/Somerset border near Yeovil. I was quoted £280 incl VAT by an indie. I'm guessing my local Audi dealer would be even more.

https://www.pscautocentre.co.uk/

Ive been to these guys twice, once for a timing belt change and then for my gearbox oil change. Mines a CVT box. The judder will be the clutch plates, mine does it, but i can live with it. Do your revs seem to judder slightly when driving at low rpm?

 

[Venomuk]

Interested to see what is suggested here. I use to own a MK4 Golf GT TDI (PD130) with 330k miles and that thing was amazing on fuel, would get 50+ easy and mid to high 40s when in town.

However, my B6 Avant seems to struggle. I get its a bigger car, but the town and commute to work are low 40s and its a work out to get a good motorway figure but I have seen 50+ so I'm thinking that perhaps it just needs a good clean out as I've not owned the car long myself. I was thinking of EGR delete and the Mr muscle to clean out the hot side of the turbo along with a diesel additive to clean the injectors and see how that all goes?

 

[Monzta]

Hiya Monza - I seriously recommend trying out FuelTone diesel additive - I had unbelievably good results with it when I used it on my dads Passat (TDi 130 engine). It went from smoking a lot to almost clean running - in fact, when I took it for it's MOT, it got an almost perfect emission figure - easily rivalling new cars! I use it on the B6 as well (same engine).
Heres a link:
https://www.ebay.co.uk/itm/Fueltone...196419?hash=item56c52c3603:g:Z-MAAOSwEiJc5Q3u

Thanks for that info @boffin486 , I bought a couple of bottle of the Forte stuff on Saturday night, one to clean the fuel system and another for the turbo. But the Fueltone stuff looks interesting so I've added it to my watched items in ebay for next time.

 

[Monzta]

https://www.pscautocentre.co.uk/

Ive been to these guys twice, once for a timing belt change and then for my gearbox oil change. Mines a CVT box. The judder will be the clutch plates, mine does it, but i can live with it. Do your revs seem to judder slightly when driving at low rpm?

The only thing my 'box does is give a very slight judder as I come to a halt. If I know it into Tiptronic mode just before I stop then I can prevent the judder. I'm hoping a fluid change and filter will be enough to cure this.

PSC Autocentre look good. A couple of hours from me but definitely do-able.

 

[Monzta]

Interested to see what is suggested here. I use to own a MK4 Golf GT TDI (PD130) with 330k miles and that thing was amazing on fuel, would get 50+ easy and mid to high 40s when in town.

However, my B6 Avant seems to struggle. I get its a bigger car, but the town and commute to work are low 40s and its a work out to get a good motorway figure but I have seen 50+ so I'm thinking that perhaps it just needs a good clean out as I've not owned the car long myself. I was thinking of EGR delete and the Mr muscle to clean out the hot side of the turbo along with a diesel additive to clean the injectors and see how that all goes?

I'm going to do the fuel additives, ultimate fuel and regular tyre pressure checks in the short term. In the longer term I'll clean the EGR system, Mr Muscle the turbo and get the gearbox serviced. I won't do an EGR delete though.

 

[Monzta]

Out of interest, how can I tell if my Multitronic has an internal or external filter?

 

[Monzta]

I think it has two filters, one exterior one that needs changing as part of a scheduled service and an internal one that's long-life.

 

[stevey83]

Out of interest, how can I tell if my Multitronic has an internal or external filter?

When i went there i was told i didnt need a filter change, as i dont have one! made it a bit cheaper. I was hoping it would cure my judder but it didnt.

 

[Monzta]

Well that's odd, everything I've read seems to mention at least one filter. I can't imagine a gearbox so complicated and valuable not having a filter to protect it. Weird.

 

[sandis pēlmanis]

Well that's odd, everything I've read seems to mention at least one filter. I can't imagine a gearbox so complicated and valuable not having a filter to protect it. Weird.

It have a strong magnet inside of the oil pan, that collects the metallic materials, but not the dirty particles......

Sent from my FIG-LX1 using Tapatalk

 

[Monzta]

I put two bottles of Forte in the tank and did a 300 mile round trip to see the outlaws in the midlands at the weekend. Not sure yet if it's worked so will keep an eye on my town fuel consumption over the next couple of weeks.

My local Audi dealership will do a fluid & filter change and a gearbox health check for £199 so at that price I'm happy to get that booked in.

 

[Monzta]

After two bottles of Forte I'm still getting poor fuel consumption. The last £20 of BP Ultimate got me just 65 miles.

A thought occurred to me though, when I first bought the car I fitted a new thermostat and coolant temperature sensor. The stat was a Gates one and the CTS was one of those cheap £5 ebay jobbies. Could one or both of these be causing me poor fuel mileage, especially around town?

 

[stevey83]

Have you got VCDS to see what your cts is actually reading?

 

[Monzta]

I've got VCDS-Lite which I'm guessing is capable of reading the engine temp. I'll try and have a go at the weekend.

 

[quattrogone]

so you are probably getting something like 20mpg? If so how are you driving? has the car been mapped? ..... maybe badly!

 

[Monzta]

My driving style is quite sedate, it's mainly town driving with a few runs out on decent roads to outlying villages. I don't think it's been mapped, the ECU looked like it had never been removed when I took it out last year.

 

[Mike B]

I wouldn't be happy with a cheap CTS.That may be the cause.Also have you checked that the brakes aren't binding?A rear isn't easy to notice and a sticky caliper can drop mpg easily

 

[Monzta]

To put my mind at rest and rule out one of them being faulty I've ordered a proper VAG CTS and stat.

Good call on the brakes, I'll get the main dealer to check them when they do my multitronic oil and filter change. I have a sort of 'wub, wub, wub' sound coming from somewhere. I thought I had a wheel bearing giving up but maybe it's a sticky caliper.

 

[Mike B]

Switch the CTS first and see.The stat would show in other ways eg not getting to 90.Brake tests are easy sense the temp with your hand after a run both the backs should be equally cool and the fronts hotter but careful not to touch the discs.The fronts would also show signs of pulling to one side if there was binding.Also useful to see if the car rolls easily on a flat surface.Finally if there is any suspicion of long term binding that caliper would have more wear on the pads

 

[Monzta]

Thanks for the tips Mike. I'll check the rear brakes next time I use the car. Pretty sure the fronts are OK as the car tracks nice and straight with no pull left or right. I'll check them for heat nonetheless.

 

[Mike B]

The rears are usually the culprits but at least you can touch the discs if there is no serious binding.Just give it a shove before you set off to see if it rolls easily after the handbrake is off cos that might be the cause of any sticking

 

[quattrogone]

Ummm... I hadn't noticed that you had a multitronic. I've always avoided auto boxes mainly for mechanical issues but secondly I always think they are juicer to run.

 

[Monzta]

The rears are usually the culprits but at least you can touch the discs if there is no serious binding.Just give it a shove before you set off to see if it rolls easily after the handbrake is off cos that might be the cause of any sticking

I took it for a 10-mile run today and all four wheels were cool to the touch when I got back. Will try giving it a shove with the handbrake off in the morning.

 

[Monzta]

Ummm... I hadn't noticed that you had a multitronic. I've always avoided auto boxes mainly for mechanical issues but secondly I always think they are juicer to run.

I wish I'd gone for a manual 'box instead of the auto, if only for the peace of mind. But having said that, the multitronic is a lovely gearbox, I love the utterly seamless gearchanges. Always worried though about them going wrong though, it's effectively a car killer if they start playing up.

 

[Mike B]

Maybe the new Cts will help then.Cant see how they could make a good one for £5.Once you get used to a good auto its hard to go back to a manual especially if you drive a lot in traffic

 

[Monzta]

Yes, I'm really hoping the OE CTS will make all the difference.

I've always been a lover of auto 'boxes and would happily stay with them for my daily driver. I have an old eighties Honda if I fancy some manual goodness.

 

[quattrogone]

Personally I think it being an auto isn't helping as you are doing a fair bit of town driving, but for a 1.9tdi it should be better than that!
I think the mutlitronic suffers when services on the box have been missed from what I've read on here. Hopefully you will get it sorted otherwise just go and get an RS4/S4 as you won't see much difference in fuel economy