Help! 2.0TDi Constant fast idle + fuel consumption worse by 10mpg

[SpiderDan]

Hi all,

 

I have a 2.0 PD TDi VRs that's done about 125k miles

 

I've recently had a series of DPF warning lights which I could not clear by following the handbook instructions, ultimately leading to an engine warning light and going in to limp home/restricted performance mode. Took it to the dealer who found no faults but forced a regen after which the car behaved normally ... briefly

 

Now I get the warning light coming on in the middle of journeys, plus every journey the car idles at ~1000rpm regardless of journey length or engine temperature, as if it is doing a self-regen all the time. Every junction, set of lights, roundabout is the same - always at a fast idle. Also I can often hear the fans running after turning enine off and today there was a definite smell of unburnt diesel. Plus my fuel consumption is awful, its gone down by about 10mpg (!) to low 40s. I've been back to the dealer who still says "nowt wrong" but clearly there is something up

 

One more thing to mention is that the trip computer is not picking this up and is still reporting low 50s mpg average for the tank (I reset trip 2 after every refuel)

 

Anyone got any ideas? My fuel bill is starting to hurt so any help appreciated!!

 

Thanks

 

Dan

[Tech1e]

Need to look through data on VCDS.

In particular

Air mass meter

EGR

Exhaust temp sensor 1,2,3

Lambda probe

Ash mass value

These will all have a bearing on regen. Plus the fact that at 100k the DPF is accepted to be at the end of its useable life.

[silver1011]

As above a VCDS scan should help to point you in the right direction. I am surprised the dealer that carried out the forced regen didn't first check for fault codes.

 

Likely a dead DPF or a duff sensor.

[SpiderDan]

Thanks for the help

DPF light came on again the other day after a long run on the motorway. Was then on country roads so I couldn't follow the procedure in the handbook. Not long after that it went in to limp home/restricted performance again, with the DPF and check engine light showing and the coil plug light flashing

I don't have access to a VCDS so booked back in at the dealer tomorrow

[Jevpls]

Likely a dead DPF or a duff sensor.

 

I agree.

[silver1011]

Now you are in limp-home mode you won't be able to regenerate the DPF yourself.

 

The only option now is a VCDS or dealer induced forced regeneration.

 

Ask the dealer for the fault codes and post them here. Also ask them for the ash content of the DPF (a helpful indicator of the DPF's condition and remaining life), a good test on dealer competency if they can manage it.

[FatblokeVRS]

Get yourself a Bluetooth adapter something like this -

http://www.ebay.co.uk/itm/2016-ELM327-HH-ODB-ODB2-V2-1-Advanced-Bluetooth-Car-Auto-Diagnostic-Scanner-Tool-/191954685107?hash=item2cb1640cb3:g:g7sAAOSwIgNXwATi

Get some of the free OBD2 apps on your tablet or phone and connect to the adapter. You can then at least get the fault codes and possibly clear them too.

[SpiderDan]

Have now got the fault code ... P2002. No ash level given

Dealer advises DPF system needs replacing :(

Edited 15 September, 2016 by SpiderDan

[meaty101]

Have now got the fault code ... P2002. No ash level given

Dealer advises DPF system needs replacing :(

Or removed!! Best thing to do imho.

[meta55b]

Have now got the fault code ... P2002. No ash level given

Dealer advises DPF system needs replacing :(

You can get the DPF cleaned out on the car. Look up DPF cleaning in your area, it works along the same lines at the engine clang Ed China endorsed.

[Jevpls]

Don't replace it - it will cost you a fortune for a thing you actually don't need.

Remove it, clean it, do whatever you wish but avoid replacing.

[cheezemonkhai]

Heard a few things about this stuff:

 

http://www.tunap.com/en/tunap-automotive/assortment/diesel-particulate-filter/