Help Please Poor MPG, Sluggish Starts and Loud Knocking

[Chapperz_a4_b8_tdi]

Hi All,

Just signed up to the site to see if you can help with a query I have in regards to my Audi.

I have an A4 2.0 TDI Quattro Clean Diesel 190bhp Black Edition Saloon
recently I have noticed that my fuel consumption is ridiculous compared to when I purchased the car which was in FEB 2018. usually, I was getting almost 580 miles to a full tank of full driving respectful 60-65mph on bypass roads 30 miles per day. Since OCT 2018 after having a recall and service it seems to be underperforming. and barely touching 450 miles to a tank.

reading multiple forums everyone says diesel in cold weather has a tendency to drop fuel efficiency but I wouldn't have expected to this level. I regularly check the tire pressure but they are brand spanking new A rated for fuel Goodyear tires. so I know I've eliminated those.

I've done the usual things giving the cars a good run to make sure DPF isn't clogged or anything like EGR.

Some mornings I'll switch the motor over and it really struggles to fire up and sometimes there is a huge amount of white smoke. I wait for the tail pigs to go out before firing too. I've noticed after driving for a good hour that it is still loud and knocky too.

Took to a dealer and they found nothing on the Diagnostic computer and won't investigate further as they've said nothing is wrong with the car.

What're your thoughts?

The Recall I had was the 17G2 code and there was about £90 spent and done under warranty. I know that isn't the Emissions scandal code but has any of you come across it and if they are related. when asked at the Audi dealer they said it was a software update.

I have spoken to multiple people about a reflash to factory settings of the ECU because I initially thought it was the VW software update fix because of the symptoms being similar. they said to look into remaps etc but to look out for the following as any of these could be an issue.

- Glow Plug issues
- Bad Fuel Injectors
- DPF
- EGR
- O2 Maf Sensor being dirty
- Air Filter
- Fuel Filter

Has anyone else experienced this with their vehicle at all and what was the outcome? I'm concerned I have a car that isn't living up to its standards and dealers are in that CBA attitude.

I have it booked in at a Audi VW Speciliast near me who do custom maps and tuning on them every day so know if they find anything it great evidence. That is booked in for next tuesday. but in the meantime any feedback or if anyone has come across this before and some info i can pass on would be awesome.

many thanks
Adam

 

[jakm15]

If your getting smoke on start up you 100% have a problem, the favourite with diesels not starting well in cold conditions is glowplugs but this won't effect efficiency once the car is running.

I'd first rule out the basics, change, oil, oil filter, fuel filter, air filter then you know you car is healthy service wise.

Secondly I'd get it diagnosed independently with VCDS and check for any stored codes.

Until you've done the above it would just be a stab in the dark to determine.

Sent from my moto e5 plus using Tapatalk

 

[Marky007]

What year is your car and what's mileage

 

[Chapperz_a4_b8_tdi]

What year is your car and what's mileage

Hey Marky007,

it's a 65 plate with just over 26500 on the clock

P.s. jakm15 thanks for the Info !!

 

[Marky007]

Hey Marky007,

it's a 65 plate with just over 26500 on the clock

P.s. jakm15 thanks for the Info !!

I was going to say clean out your egr and get vag dpf app to keep tabs on dpf and check for sticky caliper but at that low mileage not so sure .

Still worth a shot if you got bit spare time dpf app for 2.99 is a must for me I know exactly what my dpf is doing.

I got a tin of egr extreme cleaner off Ebay seems to have increased my mpg slightly.

But plumes of white smoke on start up and knocking is a issue ( is there plenty oil in there after service) my 143 bhp tdi b8.5 2012 has 0 smoke on start up with 86k in any conditions.

 

[Chapperz_a4_b8_tdi]

I was going to say clean out your egr and get vag dpf app to keep tabs on dpf and check for sticky caliper but at that low mileage not so sure .

Still worth a shot if you got bit spare time dpf app for 2.99 is a must for me I know exactly what my dpf is doing.

I got a tin of egr extreme cleaner off Ebay seems to have increased my mpg slightly.

But plumes of white smoke on start up and knocking is a issue ( is there plenty oil in there after service) my 143 bhp tdi b8.5 2012 has 0 smoke on start up with 86k in any conditions.

Cheers for the advice I'll look into those little gadgets

I have recently run some Wynn's diesel treatment formula and wouldn't want to run something else through just yet.
I know it won't make much difference but I tend to stay away from supermarket diesel too and use VPower Diesel.
I don't know if that has any effect

Yes mate the readings say max oil, mine isn't dipstick check it's all computerized

I check it every weekend.

 

[CarbonMike]

Sounds like another software update casualty...

 

[Chapperz_a4_b8_tdi]

Sounds like another software update casualty...

That was my first thought !!! and again i'm not ruling it out either.

As i mentioned it was recalled and when it was recalled was a month before the service
and that's when i noticed the changes. i can't put my finger if it's the recall or the service that has been the problem.

again i found the Recall Code was 17G2 and i got in touch with MPG Tuning to check it and they confirmed it wasn't the VAG emissions software fix and also checked the Audi Emissions site with my VIN's. Now the audi dealership i use JCT600 in sheffield didnt give me any info on the code but doing some digging seemed to come back about a coolant pump and it states there was a Software update to the ECU too. My thoughts are it's been flashed with software updated and it's goosed the MPG and Fuel Eco.