Fuel Economy on Octavia 1.9TDi is waaaay down

[octavia007]

Help!

Had a 07 plate Octavia Estate (Mk II)delivered on 23rd December...handing back my lovely hatchback in exchange.

New estate car is exactly the same model (Elegance) but with a boot (obviously). However the fuel economy is way lower than my old hatchback. Old 'un = 50 to 55+mpg. New 'un 45-50Mpg..and that's driving the thing very very very carefully. Around town I'm in mid to late 30's mpg (this is all showing on the MFD)

Have checked fuses. All OK. Have yet to check air filter...but has anyone else had this problem with a TDi before (it's the 105bhp PD)? Or does anyone have any ideas what could be causing it to drastically use loads more diesel than normal?

Any offers of help gratefully received!

[mannyo]

Does it smoke a lot under full throttle?

Things to check would be the MAF and the fuel temp sensor, if either of those is faulty it can affect fuel economy and not necessarily show a fault code.

[octavia007]

Does it smoke a lot under full throttle?

Things to check would be the MAF and the fuel temp sensor, if either of those is faulty it can affect fuel economy and not necessarily show a fault code.

Thanks for that. I've got the car booked in to a main dealer (as it's still under warranty hopefully!) for Friday 8th Jan. I'm hopeful they'll do a complete vag-com check. I'll make a note to ask the dealer to check the MAF and the fuel temp sensor also as they may not show as a fault code.

It's just a shame I gotta drive the thing from Brighton to Bristol on the 5th Jan for work!!! Probably cost me an extra few quid in the process!

Many thanks. I'll report back when it's all done. The info may be of interest to others.

Happy New Year by the way!

[octavia007]

Another question....the idle on the Octy is a little random. When the engine has warmed up to it's optimum running temperature, the idle varies (slightly) between 8-900rpm. Could this be a faulty/sticky fuel injector(s).

Also - have driven the thing without aircon on (cos of dodgy fuel consumption). If it was turned on - how much might/could it affect the mpg?

Also - on another thread - there's been loads of chat about "running in". At what point is it considered that an Octy 1.9 105bhp PD engine is "properly run in". Am i still the running the thin in at 24.5k?!?!?

Also (this is the final question) Sometimes on starting (cold or otherwise) it sounds a bit juddery or doesn't start on 1st turn of the ignition. Wass that all about then?

Can't wait to get the car into main dealer! Think I'm at risk of going all OCD over the blardy thing!

[Pud]

My 105 Tdi used to judder on starting, almost like a slight miss fire. Would only start on the second or third attempt. Try driving it up hill in 5th gear and floor the throttle, if the engine starts to judder quite strongly then its probably the DMF needs changing, mine was faulty from new I think. Dealer changed it for a single mass flywheel ,under two years ,so Skoda paid all. Have to say the car felt rougher after but I changed it soon after the work was done.

[Phil_P]

My brand new 1.9TDI is doing ~50mpg from the first 200 miles. It's amazingly smooth and quiet, no juddering or anything. So much so I wonder what all this talk of "agricultural sounding" means as I wouldn't describe it that way at all (in comparison the Fabia 1.4TDI loan car I had in December was far more agricultural sounding and a completely different beast).

[vRSLen]

Cold weather = poor economy, regardless of what you drive......

[robertb]

I must admit my PD105 has been using a hell of a lot more fuel since the weather went so much colder. I scanned it with VAGCOM a few days ago, and nothing at all showed up, and it's only a few weeks since it was serviced and all the filters including air filter were changed.

I've never had a diesel that doesn't use a bit more fuel in the winter months, so I wouldn't condemn the car until the weather settles down and we get a few warmer days.

Mike

I agree. Mine's the same, down from 50 - 55 to 45 - 50 since the weather went very cold. I noticed similar last winter.

[durhamfisher]

Also (this is the final question) Sometimes on starting (cold or otherwise) it sounds a bit juddery or doesn't start on 1st turn of the ignition. Wass that all about then?

Agree that cold weather affects mpg but your car should start first time. Suggest starting problem + juddery performance + poor mpg = fault. Keep the pressure on the dealer until he sorts it out.

[NeilUK]

I agree. Mine's the same, down from 50 - 55 to 45 - 50 since the weather went very cold. I noticed similar last winter.

Mines done the same, however I thought it may have been down to some dodgy supermarket fuel as it's been like it since November.

[octavia007]

Well. Time for a rant!! Skoda Octavia is back from the dealer. VAGCOM diagnostics completed. No faults found. I asked if no faults were found on diagnostics, could they please consider :-

• Check/swap MAF*

• Air filter/fuel filter – check and replace?

• Is the engine timing at fault?

• Faulty fuel temp sensor*

• Faulty coolant sensor?

*I understand that these faults do not necessarily show as faults on vag-com diagnostics.

I had basically told them that on £53.50 worth of diesel I am achieving a distance of 479.2 miles. A total of 48 litres (about 10.5 gallons) was used for this mileage. This equates to 45.37mpg. This is a mixture of town and motorway driving at very very careful speeds (but vast majority was steady long haul motorway driving) and use of acceleration (I was trying to not enable the turbo too much, so changing @ around 2000rpm, and coasting where I could). I would at least be expecting 50mpg on this kind of driving. My last Skoda Octavia Elegance 1.9TDi PD achieved 52-60mpg on long journeys and 44+mpg on urban driving, and I drove the vehicle much harder compared to this current Skoda). On my old Skoda I was getting 630 miles on a full to empty tank. On this Skoda, it is evident I am getting much less.

The tests I have undertaken also range from cold start mpg to review of mpg when the engine is at normal running temperature. As expected cold start mileage is lower.

The idle is a little erratic. It varies between 850-900rpm when the engine is at optimum operating temperature. Also, does not always start first time.

The acceleration is very poor compared to my last skoda in 3rd, 4th and 5th gears.

Dealer said that no faults showing on diagnostics, and that they had checked all of the above bullet points...and suggested I monitor it myself. Reckon they couldn't be @rsed on such a snowy cold day so just tell me what I wanna here over the phone. Not happy. Don't trust them. Don't trust that they've done what I have asked them to do. As this car is a lease car (which I hope to purchase at end of lease) - the servicing is dealt with via the Lease car company...and like any huge, lease car company - they're probably financially tight when it comes to servicing.

I also checked what servicing schedule I'm on...I'm on variable.... so at least any problems are not aided by duff oil etc.

Rant over! Any suggestions? What should my next approach be? Is there anything I can do myself to sort?

[octavia007]

One question: under malfunction messages on the diagnostics log I have (right at the very end), it's saying:

Vehicle System Test : Fault

Fault number: 800.11 <0067000511> <0000000000>

Then it says: Result - cancel

It repeats this 4 times.

Anyone know what this means?

[KenONeill]

My economy is all over the place, but generally down (partly more idling, but also more intermediate work and less light throttle cruising) these last 3 weeks or so.

[octavia007]

kenONeill - d'you reckon it's just altered driving styles given the unusual weather then?

I just got a real big sneaking suspicion that the MAF is out - or my air filter is a bit knacked....

[Raglits]

I'm down to about 39mpg from the normal 44ish in my Saab 1.9 Diesel... Partly the cold weather and partly the altered driving style I reckon...

[durhamfisher]

You need to focus on any repeatable faults with the dealer. In your case this is the poor starting. You should also be able to show them the eratic idle. Sort these issues out and your mpg may improve as a result.

You can check the air filter yourself easily. Read this post for assistance:

http://briskoda.net/forums/topic/148602-dumb-guys-asks-how-do-you-change-the-air-filter-on-a-mkii-octavia/

Is it due for a service? Did they not service it for you before delivery?

Edited 8 January, 2010 by stacon

[octavia007]

Stacon - I bought an air filter off my own back....as this could be a simple solution. I'll pop it in tomorrow, test it, if nowt changes after quite a few miles. If nothing changes - I'm gonna hammer the lease car company into submission until I get what I think I need. With these companies it's a case of "feck the customer...show me the money"....which is annoying as I actually intend to purchase the car when the lease period is up.

So, in answer to your question, they did not service it (as they said it didn't need servicing/ wasn't due a service)....happy days.

[Browny_37]

Around town i've never managed much above 400 to a tank. But that involves alot of stop start driving. On a run i did manage 540 to a tank.

But then again im running 225/40/R18's on the car, suprisingly the car does as many mpg at 105bhp as it did at 150bhp.

Its had its 2nd MOT under my ownership today, and i must say that the smog test results have dropped considerably since having a stock map put on. Compared to last years results.

I've also found that recent outside temps have been creating a few issues with coolant temps.

I came across Woodhead Pass last sunday and the temperature was sat just below 90 most of the way, as soon as i pulled into a layby after hitting a large pothole (luckily no damage upon inspection) I got in the car and it was making its way down towards 70 degrees C

Edited 8 January, 2010 by Browny_37

[Johnwg]

Help!

Had a 07 plate Octavia Estate (Mk II)delivered on 23rd December...handing back my lovely hatchback in exchange.

New estate car is exactly the same model (Elegance) but with a boot (obviously). However the fuel economy is way lower than my old hatchback. Old 'un = 50 to 55+mpg. New 'un 45-50Mpg..and that's driving the thing very very very carefully. Around town I'm in mid to late 30's mpg (this is all showing on the MFD)

Have checked fuses. All OK. Have yet to check air filter...but has anyone else had this problem with a TDi before (it's the 105bhp PD)? Or does anyone have any ideas what could be causing it to drastically use loads more diesel than normal?

Any offers of help gratefully received!

Not being funny mate, but "way down" in my book would mean being at around the 30mpg mark.... it's been feckin freezing from the 23rd december onwards and I've been at least 5mpg down since the cold snap.... don't worry about it and look forward to spring

[Browny_37]

Interesting to see that it's not just my temperature that drops when the engine isn't working hard. Does yours also drop if you put the heater fan on full? If mine is on low, or on auto+economy on the climatronic, it will happily sit at 90 on the temperature, but as soon as you turn the fan speed up, it will droip considerably.

Mike

Hi mike, although i dont use the fans on speed setting 4 very often i've found out that the temperature does drop when the fan is running on full, but the fans dont usually get used alot whilst driving. The amount of noise produced annoys me a little though .

Im amazed that pulling up for 5mins and letting the engine idle, will let the coolant come down as far as 70 degrees C.

[KenONeill]

kenONeill - d'you reckon it's just altered driving styles given the unusual weather then?

I just got a real big sneaking suspicion that the MAF is out - or my air filter is a bit knacked....

I know in my case it's altered driving style, and lots more time spend idling before I drive off (fire up the engine, and let it idle with climate on demist, and HRW on for anything up to 20 minutes before I drive anywhere first thing).

I'd expect a new (to me) car to be serviced before I got it, and also have suspicions about the fuel pump timing (if applicable). I know I got an extra 5mpg out of mine when the cambelt was replaced, and the garage retimed the fuel pump as part of the job.

[K1W1]

It doesn't surprise me the people are experiencing reduced mpg on diesel vehicles these last few weeks in the UK.

With the temperatures that you have been having the diesel fuel will be extremely heavily laced with anti waxing additives to allow it to continue to operate. I'm sure that if you ask the fuel companies they will tell you that your fuel has a much larger percentage of anti waxing fluids in it now than in recent warmer winters. The anti waxing additives will affect bother performance and economy.

[octavia007]

Air filter changed....the old one was a bit mucky, and there may be a slight improvement in MPG - but I'll have to give it time and put the car on a long m'way run....in warmer temperatures an' all. Starting up first time seems to be OK now. The acceleration is still very poor compared to my last Octavia...seems to be a marked delay in response on the throttle...so I'm kind of veering towards faulty fuel temp or maybe coolant sensor. Also at optimum temp (90 degrees) the idle still not static (varies between 850 and 900rpm).

Back to the lease car company..then back to the dealer I reckon....

[psycholist]

I'd be interested to hear what they say about a laggy throttle response. My PD 105 certainly responds a little more slowly than the petrol engine I had before, but I assumed that was turbo lag and from 2000 rpm it pulls as strongly as the other PD engines I test drove, so not down on power.

[gwm97e]

I sincerely hope it is a very short term seasonal effect of cold temps/diesel additives - I've done 1650 miles in my new 1.6, and it is currently only returning 38 mpg - The 1.5 Renault megane it replaced never dropped below 47 mpg at any time in the last 3 years, even in the depths of winter

Edited 14 January, 2010 by gwm97e