OK I had the dreaded injector failure back around May ish (from memory) - usual symptoms, ie. complete power loss/cut out. 1st injector was replaced by an Audi specialist (local Audi dealer was too busy to take the car at the time of failure) to the tune of £800. After researching on this and other Audi forums I realsied the the breadth of the problem and along with many others did the VOSA form and rang & wrote to Audi Customer Service on a regular basis. To their credit (although it should not have been such hard work) Audi Customer relations did eventually refund me the £800 (ish) and arranged for my Audi dealer to replace the other 3 free of charge around August time. So all my money back in my pocket and 4 shiny new injectors and wiring loom, I was happy and my faith in Audi was on the way to being restored...
The latest. Just before Christmas the car started loosing power at anything above around 2,500-3,000 rpm. Fine up to that point but shuddered and struggled to pick up any acceleration at all above that rev range. If pushed you could eventually crawl up to 3,000-3,500 rpm. No warning lights or any other symptoms.
RAC came out, followed by an Audi Assist van - no fault codes at all. All obvious things checked and fine. The Audi Assist mechanic thought the symptoms tied up with a previous problem he had seen with the same engine type and an Audi Tech Bulletin nos. TPI 201 3480 which relate to an "injector seating issue".
Audi dealer has taken the car back for investigation. To be fair to them they haven't billed me (or said they aren't billing me) for any labour or investigation costs, under the pre-tense of it being checking existing work (ie. the replaced inejectors).
They identified the fuel was contaminated (with soot) and the fuel filter clogged. They've changed the fuel filter and this resolves the problem apparently and they have done two test drives with the vehicle responding appropriately. They had originally suspected the seals on the injectors (to which I was about to argue thats Audi's problem as the injectors were replaced just 3-4 months ago), but they have said they have now checked all of these and there are no visual problems and the new injectors and seals are fine. They have also said the injector seating is fine.
Their belief is the soot was getting in before all 4 injectors were replaced, and that now, several thousand km later, the fuel filter has simply just reached it's limit and was too clogged, hence the problem. At the moment their proposal is for me to simply take the car back and run on the new fuel filter for a couple of thosuand miles then have it checked again. They have said that since the current tank still has some contamination the fuel filter might need changing again at next service. However if the problem re-occurs, and it's not the injector seals, then the next candidate is potentially the head itself (ie. namely the holes in the cylinder head in which the injectors sit). Watch this space.
One wonders if there is an issue with soot and original injector failure problem, why they aren't routinely changing the fuel filter when they swap out the injectors. However, I also wonder if there are other inherent faults with the injection system of this engine ?
(the cynical side of me wonders if during their investigation the dealer realised the injectors weren't in or seated properly, or something equally daft, and they have now resolved this but simply not admitting it - to be honest I'll be glad if this is the case as it goes, and gladly cough up the price of a fuel filter if that's the end of it)
Anyway, I'd be interested to hear from anyone else who has already had their injectors replaced by Audi but who has had further problems with the injectors, injector seals, or injector seating, or similar.
Thanks.