Octavia 1.9tdi poor fuel consumption

[johnpeeay]

Have owned 1.9tdi Ambiente for 6 years and 63k, fuel consumption has been outstanding, regularly getting mid 60's on long trips and upper 40's in city driving UNTIL two months ago I noticed the computer was showing much higher consumption than normal for one of my regular journeys. This prompted me to brim the tank and start a couple of brim to brim checks. 36.7mpg and 35.8 mpg. Took the car to local Skoda dealer and they diagnosed a faulty coolant sensor. This was replaced. Now the car gives good fuel consumption when the engine is warm BUT for the first few miles on a cold engine that's a different story. The computer will show low 30's and my present brim to brim check is looking like an overall 30-32 mpg which will have been lots of city driving but nevertheless driven sub 2000rpm 99% of the time. Anyone on this forum got any suggestions as to what else could be amiss ?

[greg123]

That's pretty poor, as you say - it should be better. Few suggestions, firstly I'd like to know it's recently been fully serviced, your tracking has been checked, you run good to high tyre pressures and all tyres checked and see a vag-com full fault scan.

If the basics are okay, things like a full intake clean, check or swap the MAF, have the injectors checked/new nozzles, and probably the easiest and potentially most inportant bit - get the timing checked. I have come across lots of issues with tdi's that in one case still started and ran okay but was too far retarded to even plot in vag-com and didn't have very good mpg as a result. It's pretty easy to set up the static timing and from there the dynamic should be okay - I usually add in a further dynamic advance as they run better with it but that's a personal thing.

Greg.

[skodaescapee]

Hi,

I know this sounds silly but a new air filter works wonders. Normally changed at 40,000 miles but a lot of forum members change at 10K knowing that fuel economy is always better with the new filter. The coolant sensor was the obvious choice. I would speak to the dealer again.

[darren_mcvicar]

change your fuel filter and give it a good service

[nazz]

Have owned 1.9tdi Ambiente for 6 years and 63k, fuel consumption has been outstanding, regularly getting mid 60's on long trips and upper 40's in city driving UNTIL two months ago I noticed the computer was showing much higher consumption than normal for one of my regular journeys. This prompted me to brim the tank and start a couple of brim to brim checks. 36.7mpg and 35.8 mpg. Took the car to local Skoda dealer and they diagnosed a faulty coolant sensor. This was replaced. Now the car gives good fuel consumption when the engine is warm BUT for the first few miles on a cold engine that's a different story. The computer will show low 30's and my present brim to brim check is looking like an overall 30-32 mpg which will have been lots of city driving but nevertheless driven sub 2000rpm 99% of the time. Anyone on this forum got any suggestions as to what else could be amiss ?
sounds like airmass meter is defective this will not show any fault on vag com or 5050b at dealer i am a vee dub tec and have had this fault many times you can get a exchange unit for about 75pounds and its simple to fit nazz bye

[quizzer]

sounds like airmass meter is defective this will not show any fault on vag com or 5050b at dealer i am a vee dub tec and have had this fault many times you can get a exchange unit for about 75pounds and its simple to fit nazz bye

Do you have to get the exhange unit from the dealership?

[nazz]

Do you have to get the exhange unit from the dealership?
yes you can pick one up at your main dealer

[greg123]

Nazz, why get an exchange one when you can get the whole think, new style (not just the sensor) brand new Bosch unit for under £60 from Euro Car Parts.

[nazz]

sounds like airmass meter is defective this will not show any fault on vag com or 5050b at dealer i am a vee dub tec and have had this fault many times you can get a exchange unit for about 75pounds and its simple to fit nazz bye
have used euro parts airmass metrers and have found thay are not as good as the ones from the main dealer but its your money

[greg123]

Euro don't make airmass metres so i'm talking about a Bosch unit, bosch boxed. Do you mean you suspect Bosch make 2 types of unit with identical part numbers, one set made slightly worse and shipped to Euro and one set made slightly better and re-packaged in a VW box?

Please don't think I'm having a go, I'm just curious as to what you mean. I could ask exactly the same about the spark plugs be they in mfr boxes or reboxed in vw boxes.

I'm not talking about 'copy' or 'replacement' parts which can vary from very substandard to better than o/e depending on the supplier & the part (eg, the better aftermarket water pumps with brass impellas).

Look forward to your opinion, Greg.


have used euro parts airmass metrers and have found thay are not as good as the ones from the main dealer but its your money

[iCraig]

Have owned 1.9tdi Ambiente for 6 years and 63k, fuel consumption has been outstanding, regularly getting mid 60's on long trips and upper 40's in city driving UNTIL two months ago I noticed the computer was showing much higher consumption than normal for one of my regular journeys. This prompted me to brim the tank and start a couple of brim to brim checks. 36.7mpg and 35.8 mpg. Took the car to local Skoda dealer and they diagnosed a faulty coolant sensor. This was replaced. Now the car gives good fuel consumption when the engine is warm BUT for the first few miles on a cold engine that's a different story. The computer will show low 30's and my present brim to brim check is looking like an overall 30-32 mpg which will have been lots of city driving but nevertheless driven sub 2000rpm 99% of the time. Anyone on this forum got any suggestions as to what else could be amiss ?

Wow that is quite poor! I get 32mpg round town out of a 1.6 petrol Octavia!

When was the car last service may I ask? Cos if it was a while ago, your better off doing the small things first. Like oil + filter change, air and fuel filters (as if either is slightly blocked it will cause more diesel to be used.

Also it doesn't sound like a airflow meter problem to me, as experience with this leads me to think you'd notice something amiss in performance too, but don't hold me on that!

Cheers

Craig