A4 170 TDI DPF PROBLEM

[leewill]

HEY EVERYONE,

I`VE GOT A A4 AVANT 2006 2.0 TDI 170 BHP MOTOR, AND THE OTHER DAY THE DIESEL PARTICULATE FILTER LIGHT CAME ON, COMMON I KNOW, AND AUDI SUGGEST DRIVING AT BETWEEN 2.5 AND 3.5 RPM IN FOURTH GEAR TO GET THE EXHAUST GASSES HOT ENOUGH TO BURN OFF THE COKE BLOCKING THE DPF/CAT,

MY PROBLEM IS THAT I`M HEAVY FOOTED ANYWAY APART FROM WHEN THE MISSUS IS DRIVING WHICH ISN`T OFTEN, OR THE DOG IS IN THE BACK AGAIN ONCE A DAY FOR ABOUT 20 MINS,

NOW I HAVE THREE LIGHTS ON THE ENGINE MANAGEMENT, DPF AND THE GLOW PLUG LIGHT IS FLASHING, I`M THINKING STEAM CLEAN THE PARTICULATE FILTER AS THESE COST £700 PLUS, CLEANING UP THE EGR VALVE, AND I`VE ALREADY CHANGED THE DPF SENSOR,

THE CAR WON`T REV OVER 3000 RPM, I THOUGHT THIS WAS LIMP HOME MODE, BUT A independant AUDI SPECIALIST TOLD ME AUDI DON`T HAVE LIMP HOME MODE, AND THAT THE ECU CAME UP WITH A LOAD OF FAULTS AND HE WANTS TO START WITH THE CHEAPEST PART AND WORK HIS WAY UP, I`M THINKING HE IS STABBING IN THE DARK AND I`D BETTER LUBE UP BEFORE HE SHAFTS ME FROM BEHIND, A MATE TOLD ME THAT DPF SENSORS ARE COMMON AND SO ARE EXHAUST TEMP SENSORS,

SO DO I SOUND RIGHT OF MIND, WILL THIS HAPPEN AGAIN, AND ANY OTHER ADVICE WOULD BE GREATLY recieved

 

[Belle427]

a whole load of other fault codes can be thrown up confusing the issue sometimes when a component fails, take it to someone with the correct diagnostic kit who knows what they are doing and you wont get shafted

 

[gregers]

are the rear brake lights working?

 

[leewill]

ok just an update incase anyone else has this problem, i took the dpf/cat off and steam cleaned the inside out until clean water started coming out of the end of the pipe, this took about 10-15 mins, took the egr valve off to clean it up, noticed some oil in the electrical plug so took the black plastic cover off and noticed the plastic cogs inside that open and close the valve were stripped so the egr hadn`t been working, new egr valve fitted and cleaned dpf fitted, 20 mins down the motorway, slowly the car started returning to normal driving feel, then one by one the lights went out, happy days believe i`ve cured the problem, and yes the brake lights work.

 

[A4Pat]

Just read your thread leewill with interest. I have had similar issues and done some radical cheap solutions on the same car.
Logged much of my trials and tribulations in vwaudiforum.co.uk in A4 B7 section. If the DPF issue comes back I recommend you go there. Don't know what your mileage is but DPFs do reach end of life. Ash deposits fill the filter and it won't come out with steam or water. Mine has 145k on the clock and was unserviceable.
Also some good stuff on my piezo injector failure and replacement in there.

I'm now interested in EGR - think it may be to blame for really rich and rough running on warm up. Will look inside the plastic cover tomorrow.

Thanks for a useful thread.

Patrick