Audi a4 2.0 tdi loss of power - turbo not kicking in

[nice red GTi]

Hi All,

My 2006 A4 2.0 tdi (TDV) developed a problem this weekend. It has lost power. The car still drives well and can get up to 70 / 80 mph however it is slower than normal - it feels like a non-turbo diesel now.

Normally, if you put your foot down the car had a little turbo lag then would push you into your seat, however now it does not it just slowly gains speed - it still keeps up with traffic but just did not give me any confidence on motorways etc.

I cannot feel or hear the turbo kicking in. Does anyone have any ideas?

The car was serviced a few weeks ago with new air and fuel filters fitted.

Additionally, the MPG has been a little poor over the weekend (40 - 45mpg) however I was at the lakes so a lot of up and down hill driving. I have actually found this A4 not to be as great on fuel as my last A4 (a 2005 2.0 tdi also - which could return between 55 and 65 mpg) this one seems to average 50 to 55mpg - I've never managed to get near to 60mpg.

Any help would be greately appreciated.

Matthew

[Guest 2]

Have you had your injectors checked by Audi? There is a free recall for those.

Has the car been scanned for faults?

[nice red GTi]

Hi, not yet. I just returned froma weekend away.

Would the recall likely apply to my car? I did have the free recall done about 18 months ago where they updated the software on the ECU. Do you have any info on the injectors?

I had thought the problem may be a turbo hose coming off (my cousin had this in his A3 2.0 tdi (however I? have just looked and cannot work out which hose it could be).

Not yet had the codes read, I want to by a cable off e-bay but not sure (some seem to be £15 but I'm a bit dubious).

Regards

Matthew

[Guest 2]

It might, ring Audi and get them to check with the chassis number. All injectors and loom replaced foc.

Theres abig thread on the Passat section https://www.vwaudiforum.co.uk/forum/s...pening-at-last!! but they do affect Audi models too.

If you want a forum member to scan your car for beer look here https://www.vwaudiforum.co.uk/forum/f...sers-Locations for possible locations.

I can't comment on the eBay cables as I don't own one but the genuine Ross-Tech cable which I do have, is a great tool and worth the £250. Expensive but worth it as a scan would be ~£100 at the dealer.

[nice red GTi]

Thanks Chris,

I'll give them a try tomorrow. I'll let you know what happens.

M

[nice red GTi]

Hi Chris,

Phoned Audi - the car is not subject to a recall. Good news however - I took the air filter housing and induction section off and refitted it and the turbo now kicks in (not sure if doing this has solved the problem or its just a coincidence - but its working!).

Thanks for the advice though.

M

[Guest 2]

Ah well, worth a try anyway!

Thats good, maybe the hose was loose and messing about with the air. Did you check the hoses for splits while you had them off?

[wheely88]

If you took the induction section off you probably disconnected/reconnected the MAF sensor. I recon this is where my money would be. Any leak pre-turbo in this area would be unlikely to give you the symptoms you suffered. Also you normally get a whole lot more smoke coming out if the ECU believes nothing wrong (yet turbo not working).

[mauricedar]

There was a recall for A4 B7 on hose onto intercooler (underneath front of car) My car was going OK but it was replaced F O C

[Hodgkins1985]

Had same issue and tried loads of things. The air pipe coming off the air filter has a sensor on the air flow meter I disconnected that sensor and car drove perfect! Car felt like it had a turbo prone but bought a new MAF and it's fine now!