zUgan Posted February 15, 2010 Report Share Posted February 15, 2010 Hello, First post on tyresmoke, I have experience of this (or very similar) engine in a Fabia vRS and whilst I realise that the A4 Avant is a heavier car I have been a bit disappointed with the economy I have been getting. It's an Avant, 6 speed with 85,000 miles. Lately though I have been starting to think that something is not quite right the economy has dropped right off. Starting problems, when cold (left overnight) takes a couple of seconds longer to start, idles roughly and coughs out some black smoke. On the move, a bit hesitant and prone to stalling, power delivery is not smooth with flat spots, most noticeable on gentle throttle in lower gears. Even during the day I can see plenty of black smoke out of the exhaust on part/full throttle when the boost comes in. Economy, the best I have managed out of a tank is about 47mpg (calculated - about 2mpg less than DIS) and that was driving like a complete granny. Then it took a nosedive and no matter what I do it's doing just less than 40. Same usage pattern, tyres are all inflated correctly, no extra weight, climate on ECON, I'm the only driver and usually just me in the car. Commute: 20 miles to work. 2 free-flowing towns joined by dual carriageway. I never see more than 45 on the DIS. From what I've read, 50 or perhaps more, being careful, shouldn't be unobtainable? Things I have done... 1st red square: Cambelt change at VAG dealer. 2nd red square: Cruise/DIS fitted by shark90 3rd red square: Replaced black temperature sensor with green one, due to error code when Ben scanned the car as part of the cruise fitting. Wondered about MAF sensor, read about temporarily disconnecting it, so did that this weekend. Drove a mile up the road. Car very slow, seemingly no turbo boost, no smoke though. Any ideas? 1 Link to comment Share on other sites More sharing options...
zUgan Posted February 17, 2010 Author Report Share Posted February 17, 2010 No-one? Something is not right. Current tank is on course to be even less and it only did 35mpg on the way to work this morning. I think I might attempt to take the EGR valve and inlet manifold off and clean it over the weekend. Link to comment Share on other sites More sharing options...
EddyH Posted February 17, 2010 Report Share Posted February 17, 2010 Have you checked the codes recently? Even though you've changed the coolant temp sensor that would still be my first suspect regarding the cold starting problem. The MAF is the likely culprit of poor economy, either bite the bullet and replace it or do some air flow logs with vagcom first to diagnose it. Link to comment Share on other sites More sharing options...
zUgan Posted February 17, 2010 Author Report Share Posted February 17, 2010 Thanks for the reply Eddy. I don't have access to VAG-COM. Bullet bitten, ordered a new MAF, will put it in this evening. Fingers crossed. Link to comment Share on other sites More sharing options...
cruiser647 Posted February 17, 2010 Report Share Posted February 17, 2010 It's worth cleaning the EGR anyway if you can. Link to comment Share on other sites More sharing options...
Milo Posted February 17, 2010 Report Share Posted February 17, 2010 I averaged 41 mpg in a 2003 1.9 Tdi Saloon over 3 years/25k miles. Only very rarely did I break 50, that took miles of pootling on a motorway. Anything around 38-42 in an avant sounds fine to me. Link to comment Share on other sites More sharing options...
zUgan Posted February 18, 2010 Author Report Share Posted February 18, 2010 Changed the MAF and air filter. Less smoke and much smoother. Will have to wait and see if the mpg has improved. Milo, my concern was more the obvious loss of economy and refinement(!) that is illustrated by the graph above. Overall mpg between cars and drivers is going to depend on lots of factors. In this case, I know it is capable of at least 46-47/tank (calculated) without extended motorway runs and I have seen 55 (average trip - admittedly on the DIS) in the past for gentle motorway journeys. Link to comment Share on other sites More sharing options...
benjie Posted February 19, 2010 Report Share Posted February 19, 2010 (edited) I have to echo what some people have put - replace your MAF, also, perhaps the vehicle speed sensor (sometimes called the crank sensor I think) as that can cause juddering at low revs - though it usually shows a code on VCDS. Definately clean out your EGR, it'll be filthy in there and restricting air flow. The poor starting may be glow plugs. Mine (same engine, and mileage!) was a 2-4 second started until I changed the glow plugs - they're bloody hard to get to though, esp plug 3 so you may want to get a professional to do them. MPG - My quattro A4 is supposed to get 43, but with colder weather, the mpg goes down, so I've been getting 36-40, whereas in the summer I can touch 50 (if v careful!) I would wait until the weather improves, then address it if it's still pants. How long since an air/fuel filter change? If it were me, I'd get the maf changed, make sure the fuel/air filters are ok, do the EGR and change the glow plugs and see what happens. ** I'm very much thinking out loud about things that have hampered my TDI's over the past 6 years, so feel free to use/not use any of the above points. Edited February 19, 2010 by benjie Atrocious spelling, I'm a teacher for Christ's sake! Link to comment Share on other sites More sharing options...
cruiser647 Posted February 19, 2010 Report Share Posted February 19, 2010 Changed the MAF and air filter. Less smoke and much smoother. Will have to wait and see if the mpg has improved. Milo, my concern was more the obvious loss of economy and refinement(!) that is illustrated by the graph above. Overall mpg between cars and drivers is going to depend on lots of factors. In this case, I know it is capable of at least 46-47/tank (calculated) without extended motorway runs and I have seen 55 (average trip - admittedly on the DIS) in the past for gentle motorway journeys. Also, what fuel are you using? Link to comment Share on other sites More sharing options...
zUgan Posted February 19, 2010 Author Report Share Posted February 19, 2010 Cheers all. Will have a crack at cleaning the EGR/inlet manifold over the weekend. Fuel: Sainsbury's City Diesel. Good point! I'll stick a tank of something better in next time. Link to comment Share on other sites More sharing options...
cruiser647 Posted February 19, 2010 Report Share Posted February 19, 2010 Actually Sainsbury's stuff is pretty good. It's BP. Get a bottle or 2 of Millers Diesel+ from Oilman. I need to, it about time I stuck some of that in the Bora.... Clear the injectors. Link to comment Share on other sites More sharing options...
jwo Posted February 19, 2010 Report Share Posted February 19, 2010 My average over 85,000 miles is about 40mpg (worked out the proper way with pencil and paper - although i now have the jazzy iphone app too). If you were expecting 45mpg with every day use you may well be upset... Link to comment Share on other sites More sharing options...
razi Posted May 18, 2015 Report Share Posted May 18, 2015 Same problem help Link to comment Share on other sites More sharing options...
cruiser647 Posted May 18, 2015 Report Share Posted May 18, 2015 Hey Razi What issues are you experiencing? How old is the A4 and what engine does it have? Any mods or updates? Link to comment Share on other sites More sharing options...
NewNiceMrMe Posted May 18, 2015 Report Share Posted May 18, 2015 Perfectly normal consumption by the sounds of it. I had a 54 plate Avant TDi Sport 130. I couldn't get near the figures you're saying you did and I was doing a 250 mile a day round-trip commute on the A1. That was on an almost brand new car with full dealer servicing (although they're crap) throughout. I took that up to 50,000 miles on the clock and it was only ever used for the same commute (mainly because I hated the bloody thing and it was purely for getting to and from work). Mind you, that now makes me the fourth person in this thread to say it is perfectly normal to get around 40 mpg....but I'm guessing we're all wrong.... Link to comment Share on other sites More sharing options...
cruiser647 Posted May 19, 2015 Report Share Posted May 19, 2015 I get 38/40 out of my diesel A8 quattro on my A1 commute. The Bora 115 I had, I got approx 55 on the same commute The A6 2.5 TDi quattro, I got 45. But I don't rush around really. Sit at about 70/80, just cruisin' and taking in the view. Link to comment Share on other sites More sharing options...
NewNiceMrMe Posted May 19, 2015 Report Share Posted May 19, 2015 (edited) I have an average of 48.1 mpg out of the 520d - but it is all motorway miles (well, the bulk of it anyway) so I'd expect that. It is also a massively better and more efficient engine than the 130 TDi Massey Ferguson that Audi made. The only point I was trying to make was someone else joined a thread in which numerous people have said the OP's consumption sounded about right, and then someone else joins in years later and says "help". Plus, it is so difficult to account for driving styles and what one person considers 'extended motorway miles' and I'd probably think of as a short trip! Edited May 19, 2015 by NewNiceMrMe Link to comment Share on other sites More sharing options...
cruiser647 Posted May 19, 2015 Report Share Posted May 19, 2015 I have an average of 48.1 mpg out of the 520d - but it is all motorway miles (well, the bulk of it anyway) so I'd expect that. It is also a massively better and more efficient engine than the 130 TDi Massey Ferguson that Audi made. Speaking of Massey Fergusons......... I had the displeasure of hearing a diesel X-Type start and pull away very close to me, as I had just walked past. Not sure if it was the 2.0 or the 2.2 Feck that was bad. Bloody awful racket it made. Fecking loud and coarse. How did that engine ever get into a Jag? Link to comment Share on other sites More sharing options...
Tipex Posted May 19, 2015 Report Share Posted May 19, 2015 Only 48.1 from the 520 doing motorway miles? I'd expect that to be nearer 60mpg. Ours get almost 48 around town. As for the noisy Jags, yes they do get a bit rattley and clattery once the miles pile up, poor servicing is usually the culprit too. Link to comment Share on other sites More sharing options...
Mook Posted May 19, 2015 Report Share Posted May 19, 2015 It depends how fast you drive on the motorway, surely? I can get a 25% variance in mpg depending on whether I drive at 70 or 90. Link to comment Share on other sites More sharing options...
Tipex Posted May 19, 2015 Report Share Posted May 19, 2015 (edited) This is true, my old Mondeo ST TDCI was better at 90mph than it was at 70, due to the gearing in 6th, it'd do 60mpg all day 90mph, but drop to 70 and it was low 50's mpg. Edited May 19, 2015 by Tipex Link to comment Share on other sites More sharing options...
NewNiceMrMe Posted May 19, 2015 Report Share Posted May 19, 2015 Only 48.1 from the 520 doing motorway miles? I'd expect that to be nearer 60mpg. Ours get almost 48 around town. As for the noisy Jags, yes they do get a bit rattley and clattery once the miles pile up, poor servicing is usually the culprit too. 60 mpg? Not a chance. You might do if you drove like Miss Daisy constantly, but not a standard 520d M Sport. I also find it very difficult to see one getting 48 mpg around town. I'm not saying your guys aren't, but that is quite remarkable if they are. I would get 40 mpg around town and Honest John's site shows most 520d's average 42-44 mpg from owner submitted stats. I averaged 52 mpg over 1,000 miles last week. However, that was almost all (95% of it) A1/M1. In reality I might end up on A and B roads. I'll often do 250 miles on the motorways and then 50-60 miles on all manner of other roads to get to my destinations. I certainly don't hammer the car but I don't drive slowly either. My motorway speed is likely to be in the region of the national speed limit or X amount higher depending on who is reading this thread. But I don't do X amount higher = ban speed. No sir, not me. Link to comment Share on other sites More sharing options...
patently Posted May 19, 2015 Report Share Posted May 19, 2015 These are taxi drivers, MrMe. Never drop below 6th gear iirc 1 Link to comment Share on other sites More sharing options...
Mook Posted May 19, 2015 Report Share Posted May 19, 2015 The only 2 litre tractor BMW I've seen get over 60mpg consistently on motorway runs is a mate's 320ed. Which he's now chopped in for a 335d Xdrive Link to comment Share on other sites More sharing options...
NewNiceMrMe Posted May 19, 2015 Report Share Posted May 19, 2015 These are taxi drivers, MrMe. Never drop below 6th gear iirc I have an eight speed gearbox and it probably spends a good 75% of its time in 8th! Link to comment Share on other sites More sharing options...
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