2015 Audi A6 Actuator Help

[G.Douglas]

Hi all, 

Looking for a bit of advice if possible.  I've recently purchased a 2015 Audi A6 black edition (2.0tdi 190ps) which I've had now for around 4 month's,  the car I absolutely love, having previously owned a HR 350z I thought it was time to go for a bit of a change and get something more comfortable and sensible.  Cut a long story short the car has been running fine up until last month,  the first issue I noticed is that the glow plug light started to flash which lead me to believe the DPF was getting choked,  I was curious as to why this was the case as I don't use the car for short journeys and was aware of how to drive the car so to speak when the car was on a regen cycle,  after consulting with my garage they noted that the DPF was fairly chocked up when buying the car the previous owner did state that for the last year the car has been doing short journeys so I'm assuming this has contributed to this,  they did note that the car was also unable to do a forced regen and pointed out that the exhaust temperature sensor had failed (post dpf) this was then changed again the car would not force regen,  we opted to remove the dpf for cleaning along with the turbo which apparently was an absolute nightmare in removing due to the location of the DPF on the newer Audi's.  The DPF and turbo have now been cleaned and put back into the car one thing they did observe that whilst removing the DPF & Turbo was that a section of the turbo actuator was moving freely which can cause boost issue's (apparently,  apologies for my lack of experience on this matter this is my first time owning a diesel).   Anyway I've had the car back now for around 1 day and within 5 hours of getting the car back my glow plug light has come on again followed by the EML and of course limp mode,  I've taken the car back for a diagnostic read using VCDS and it's coming up with P0234 overboost detected + an actuator fault code (don't remember this code to hand).   The garage I use contacted Audi to query this who advised to check if the actuator has seized this was not the case however as mentioned we discovered there is a section inside the actuator that's moving freely which they *assume* is causing the car to over boost sending it into limp mode,  I do note the glow plug light clears when turning the car off but after a few miles it returns,  I also have some smoke on boost before the light comes on.   

 

So I've tried researching this and I'm coming up a bit short,  does this point to an actuator fault or could something else be triggering this?  And if so how easy are these to change.  From what i gather these are electronic now,  the garage I use have advised they will be able to change this as the actuator doesn't appear to be too expensive however are concerned that they may need to remove the DPF/Turbo to remove the actuator which last time was a 7 hour job resulting in the engine mount coming off and also the fact that because it's electronic it will need programmed which they are happy to do if they had the programming sequence for this so I'm kind of at a loss now of where to go with this,  the actuator is apparently on back order from Audi at the moment due to them being prone to failing as quoted by Audi yesterday.  I do use the car for work so i'm a bit dubious about driving the car at the moment as I really don't want the DPF blocking again after it's just been cleaned.  

Any help will be appreciated thanks. 

[G.Douglas]

Just an update,  I've had a look at the actuator arm whilst the car is at idle stationary and I notice the actuator arm is for lack of a better term dancing up and down not massively fast almost like a slow pump moving.  

[Pinney27nick]

Hi, I have had my Audi a6 (on a 65plate) and I am having the same issue, the glow plug light will come on and put the car into limp mode as you say turn off and back on and it reset, but it will go into limp mode at low revs or if you put your foot down it’ll go into limp mode, one person has told me it’s due to exhaust/DPF been clogged up and another person has told it’s due to the variable actuator which comes as a complete unit with the turbo (don’t know how true that is) but luckily I only bought the car 4 months ago so it’s still under the 6 months warranty. So we shall see on Saturday when it goes back to the garage. 

[edzini]

Hi guys,  just looking for an update on this as my Audi A6 Ultra is doing the same thing.  Actuator is pumping up and down when idling and,  there's a strange pulse sound coming from the engine.  Only happens when the car heats up 

 

Thanks

[Magnet]

Hello Ed,

Probably best to send Glen a PM, since he hasn’t been on here for a few years. Hopefully, he may be using the same registered e-mail address. 
Kind regards,

Gareth. 

[Steve Q]

23 hours ago, edzini said:

Hi guys,  just looking for an update on this as my Audi A6 Ultra is doing the same thing.  Actuator is pumping up and down when idling and,  there's a strange pulse sound coming from the engine.  Only happens when the car heats up 

 

Thanks

Have you had a diagnostic check to see if any fault codes flag up? 

Have you looked to replace the actuator?