A6 TDI 130 PD Intermittent power loss

[really wants an RS6]

Hello, as the title suggests I have an A6 52 reg 1.9 TDI 130. Occasionally as I am accelerating the car will not respond, If I let off the accelerator and then press it again the car will respond normally,and at other times this does no good. This problem seems to be steadily getting worse. The car is great apart from this and has a full service history. I know it could be the MAF sensor or the N75 valve, Does anyone know how to test these ? Cheers for any help you can give, John.

[Col]

If you have vagcom you can test the MAF by logging the airflow, however I'd say it's unlikely to be the MAF.

The N75 can also be tested from vagcom via the output tests once your logged into the engine control module, you will simply hear the N75 solenoid clicking.

I'd also check out the throttle position sensor as well (throttle pedal with attached sensor).

Do you have cruise ?

If so, you could eliminate both the MAF and the N75 by accelerating with the cruise.

Also the VNT turbos or the vanes in them can get sticky if the engine isn't rigorously excercised on a fairly frequent basis. This will also give diminished performace and smoke out the back...

Does it smoke when you hoof it btw ? ... could point to the sticky turbo fault.

Best advise is to get it scanned and checked by someone with vagcom. I've got vagcom and am in Maidenhead Berks and could help but no doubt your in Aberdeen or somewhere equally distant.

[salty]

Hello, as the title suggests I have an A6 52 reg 1.9 TDI 130. Occasionally as I am accelerating the car will not respond, If I let off the accelerator and then press it again the car will respond normally,and at other times this does no good. This problem seems to be steadily getting worse. The car is great apart from this and has a full service history. I know it could be the MAF sensor or the N75 valve, Does anyone know how to test these ? Cheers for any help you can give, John.
HAVE YOU TRIED THE SIMPLE THINGS FIRST LIKE CHANGING THE FUEL FILTER SALTY

[really wants an RS6]

Suprisingly I am in High Wycombe and thanks for the prompt reply. I do not have cruise, but why would that prove it wasn't the MAF sensor ? No smoke, no strange noises just a lack of power, and I mean a big lack of power.
PS. I am not doubting your knowledge, I am just curious as to why cruise would allow the car to accelerate with a knackered MAF sensor.

[really wants an RS6]

HAVE YOU TRIED THE SIMPLE THINGS FIRST LIKE CHANGING THE FUEL FILTER SALTY
No mate I assumed that as it had a service a month ago and it is on long life servicing that the fuel filter would have been changed but I will check cheers.

[Col]

Suprisingly I am in High Wycombe and thanks for the prompt reply. I do not have cruise, but why would that prove it wasn't the MAF sensor ? No smoke, no strange noises just a lack of power, and I mean a big lack of power.
PS. I am not doubting your knowledge, I am just curious as to why cruise would allow the car to accelerate with a knackered MAF sensor.

Having re-read my post it that bit makes no sense !

What I meant was...

Accerating with cruise would confirm throttle sensor on the pedal as being the culprit or otherwise.... why I typed and referenced MAF, god knows.

[really wants an RS6]

Cheers mate, now I understand. Why do you say it's unlikely to be the MAF meter (not sensor, I don't know why I put sensor) I thought VW and Audi had a problem with those or was this sorted before 02, or was I misinformed.

[Col]

Yes, the MAF are notorious for failing however it usually happens very gradually.

[really wants an RS6]

Yes, the MAF are notorious for failing however it usually happens very gradually.
Hmmm, drove the car to work this morning (20 miles) and it was fine all the way. Will see what it is like on the way home and let you know.