A3 2.0TDI Sport MPG Poor

[Jamsie456]

My car has the dreaded porous head/gasket I believe. (Rough start up kicking out white smoke, losing coolant). So I chucked some kseal in and think im gonna sell it soon!

Anyway until then Im not happy because its costing me so much to run!

Combined MPG is about 30-36 which I have researched and although not unseen it should be getting much more. I had my mate plug it in to read codes and only faults which came up were rear wheel abs sensor faulty, cylinder problems (guessing that's the head problem) and a radiator fan fault.

Tbh I don't really want to spend much more money investigating things on it but anyone know what could be causing the dire mpg?

Tyres correct psi, air filter clean had service about 2 months ago.

 

[Meejaman]

How you use the car has a massive impact on mpg: length of usual journeys, stuck in traffic or open roads, heavy or light right foot. 30-36mpg may be good depending how you use it, so tell us more.

90% of my use is 8 miles there and back again to the gym, open roads, making progress but I'm light on the brakes. According to DIS 2 I average over 60mpg. If I took it to the train station half a mile away each day, your mpg would be good.

 

[sliced]

Bad move with the k seal, gonna make it harder to diagnose

 

[Jamsie456]

I do about 100-130 miles a week and have been putting in £50 a week its terrible. Most days It is short journeys but I use as little throttle as possible.

Could it be the radiator is on too much and draining power? Any way to find out without going to a garage?

Im going to have a look at a garage tomorrow who may have a replacement head/full engine but if this is to be expected from a 2.0tdi Its definitely getting sold!

 

[sliced]

Head gasket is a common problem on earlier tdi's

 

[AudiMafia]

since i put a new clutch i am doing 45-47 mpg in London, yours is way too low,

 

[TDI140]

Headgasket number on BKD ending in A high percentage of headgasket problem
ending in B few headgasket problems
ending in C (like mine) no head gasket problems

30-36mpg is way to low mate check boost hoses see if theres any leaks i get 39-42mpg when abusing my car in 2nd third and fourth gears

There clearly an issue there mate

 

[Jamsie456]

Im wanting rid of it tbh. I've had it plugged in and nothing related to MPG showed up. Only a radiator fan error which I doubt would cause such a big MPG loss.

After a bit of googling ive heard the MAF sensor could do with cleaning so il try that. Also is the coolant temp sensor easy to replace?

If these two don't work im getting rid ASAP costing me a bomb for diesel and for a garage to investigate will cost more.

 

[Rhyso]

Haven't you answered your own question? If your head gasket is failing then the air / fuel mixture is surely all to pot??

replacing parts without proper diagnostics is just throwing good money down the drain

 

[T8DPR]

even the C prefix wasn't completely free of the head problem

back on main topic, check your brakes aren't binding, do your alloys collect a suspiciously large amount of brake dust?

I get 600 miles out of a tank in the summer months, more like 520 out the tank in winter months, if you're getting anywhere near that, don't be so worried

 

[TDI140]

600 do you even use the accelerator ? Lol

i get 400-430 with the set up at the moment

 

[Jamsie456]

Could be onto something with the brakes....I have a ABS light on the back left wheel which I need to get sorted. When I had my back brakes changed about 2 months ago the wheel with the error shed a lot more brake dust than the other.

 

[SAiLO]

600 do you even use the accelerator ? Lol

i get 400-430 with the set up at the moment

Your engine is slightly modified.

 

[T33_BKD]

even the C prefix wasn't completely free of the head problem

back on main topic, check your brakes aren't binding, do your alloys collect a suspiciously large amount of brake dust?

I get 600 miles out of a tank in the summer months, more like 520 out the tank in winter months, if you're getting anywhere near that, don't be so worried

Audi have told me that my OSR brake calliper is binding, but i do not see any excessive brake dust and am still getting ~450miles (140 BKD). did i mention that they want £320 to fix this!

 

[Jamsie456]

Got my abs sensor fixed. MPG still low. 28mpg today and I dread to think what that really is if DIS overreads.

It doesn't pick up speed very well I don't know if that's just the 2.0tdi engine for you.

Ive read about coolant temp sensors but my temperature gauge acts normally and there were no faults showing about the sensors.

Are they cheap enough to try replacing?

 

[bigal23]

half a tank 250-300 miles and that's with the odd planted foot. mapped to 230 with big turbo kit

 

[Jamsie456]

Ive found the part needed to replace the sensor its only cheap so worth a try.

Which sensor is the one which controls the dashboard temp reading and which is the other? As my dashboard temp reading seems to be working fine.

 

[emznjav]

I get about 560 miles to a full tank 80 %motorway 20 % local to a full tank.

 

[Boon]

600 do you even use the accelerator ? Lol

i get 400-430 with the set up at the moment

Ive just been in France, filled up before I went, done 547 miles on mostly autoroutes at mainly at 70-80mph and come home with quarter of a tank left

But get around the same as you around town with some spirited driving