A6 is shaking on startup

[M1K3Y]

Hi.

My A6 has developed a fault.

Sometimes but not all the time the car will shake on start up. It does it whether the engine is hot or cold and no warning lights are on the dash or anything.

The revs go up slightly and back down but no pattern or rhythm just random RPMs.

It did this again today and while it was shaking I didn't notice the RPMs move much if at all.

Anyone shed any light.

The car has 40k and is under warranty so it's again ll perfect time to get this sorted.


Thanks in advance

[Guest 2]

Which engine? Let the warranty sort it, don't go fiddlig with anything.

[M1K3Y]

Which engine? Let the warranty sort it, don't go fiddlig with anything.

Hi it's the 3.0 tdi Quattro.

The thing is there's no lights no beeps no nothing. The car is simply thinking everything is OK.

[M1K3Y]

Also it's the 2010 facelift.

I have VagCom did a scan and nothing showed up in all the modules.

[gupsterg]

I had this for a while on my A6 2005 3.0 TDi ....

Trust me has been a real PITA to get it to behave on idle/startup plus many £££ sunk into it ...

[M1K3Y]

I had this for a while on my A6 2005 3.0 TDi ....

Trust me has been a real PITA to get it to behave on idle/startup plus many £££ sunk into it ...

Did you manage to narrow it down to something?

If it does happen again I'm plugging my VagCom into it and taking screen shots of some of the values like injector quantity etc and then screen shots when it's running normally.

But mine only does it in a blue moon so it's going to take a while

[gupsterg]

Measuring blocks is probably your best bet to capture info.

This maybe handy info, Link:- Audi Portal: ECU Diagnostic . Audi A6 4F (2005- ) . Engine Control Unit J623

Also you may wish to have these to read (use google to gain) :-

SSP350 The 3.0l V6 TDI engine
SSP351 The common rail fuel injection system fitted in the 3.0l V6 TDI engine

Also get:

3000cc V6 TDI Audi (page 20 onwards shows the different EGR system fitted to yours vs my earlier engine)

If you ref it it yours will differ from it as the additional EGR cooler is not fitted IIRC.

I find FastStone screen capture allows me to get screen videos of VCDS easily, do a search for my idle thread and read it if you have time, there are examples of my videos near the end plus all the processes I went through.

I have also read info stating the the facelift A6 (4F) that you have in the V6 had a technical service bulletin (TSB) which updates the EGR behaviour, I will try to fish it out, if you respond to my PM you could ask audi main dealer if it has been done or needed.