Failed injectors - 3.0V6 TDI - any idea what causes it?

[Hopmeister]

Hello all,

I'm another £800 lighter after the car snapped another injector stretch bolt. I've now swapped them all out, then 24 hours later a mate told me there is an uprated version out. 61,000 and it's snapped injector 2 bolts, failed 2 injectors and bent 2 of the HP fuel pipes.

I do love how at 70mph on the motorway when the car decides the injectors failed that it just shuts off the power. Very interesting for the drivers behind you when the flashing yellow glow plug starts and you do a Top Gun carrier landing from the fast lane to the hard shoulder. Definitely not funny. Limp home mode is one thing, hitting the stop button is another.

I love the car but Audi must know these bolts are ****. I've googled since and the 2011 MY seems prone to snap them after 60,000.

Questions:
Is there a known problem with these injectors? (I have searched but found nothing definitive in the returns)
Can they be fixed?
Can you pre-emptively check them for whatever it is that fails?
Are there upgraded ones that don't fail?

Or do I do drives into Europe with spare injectors and replacement stretch bolts and my VCDS ;)

Thanks and apologies for the questions but my holiday savings have now vanished thanks to 2 x £2.50 bolts snapping and spitting the injectors:aargh4:

Apologies if the answers are on the forum, but my searches haven't returned anything concrete.

[Crasher]

Yes it is a very well known problem within VAG with internally circulated TPI’s, in essence the bolts are not good enough, perhaps ARP could be persuaded to make them?

[Hopmeister]

Hi Crasher,

Thanks, these should be a recall to be swapped by Audi or listed as a service item. It's a very expensive and dangerous "***!" moment and repair bill.

I've been told there are uprated bolts at £3-50 each. I'll get some. Still doesn't solve the injector issues. All I've found is that apparently the piezo crystals fail. My suspicious mind would start thinking water in the fuel from the E20 additions. My P38 does 27mpg on pump diesel and I got 35 mpg on 95% veg oil, splash of 4* and injector cleaner. So something is going on with pump diesel.

cheers
Hopmeister

[Crasher]

So something is going on with pump diesel.

Probably but apparently all these changes we are making in the UK to reduce our Carbon Dioxide emissions are single handily going to “save the planet” and stop a “climate emergency”...:banghead:

[limecc]

I just got my 2012 Q7 back from the VW Audi specialist and it's wiped me out. £1100 total with over £550 in parts for one failed injector @ 100K miles.

I was told that the copper seals start corroding and leaking, eventually the bolt (which was polished on one side by vibration from the injector) gave way and sheared. The injector and bent fuel pipe had to be replaced. I wasn't confident that the others weren't in a similar condition and indeed the other rearmost injector was going to be next. He recut all six injector seats and used new bolts along with the latest design seals which will mean hopefully the problem will never return.

I did actually have some warning that something was amiss. When the engine was cold on holiday I heard what I attributed to be a timing chain rattle, especially noticeable with the windows down and the engine noise reflecting back off the farm's stone wall. It was a progressively worsening rattle over several months that went away when the engine warmed up. Now all is quiet again when cold starting.

Edit: maybe the copper seals work-harden after repeated heating/cooling cycles and the injector bolt is no longer at the correct torque when the engine is cold. Who knows?

[Crasher]

Across the VAG range there are many common failures that could be prevented with manitaience, such as changing the bolts and seals at 100k miles but I have tired of advising people about this sort of work as their eyes just glaze over or you get accused of trying to "rip them off" so I don't bother anymore, not even with BXE con rod bearing failure.

[memgrubb]

Hi. What were the symptoms you were experiencing prior to identifying the fault please?

[Crasher]

You can get a tick tick tick at idle, a nasty smell through the heater when stopped and go oozing out of the head onto the exhaust, hence the pong

https://live.staticflickr.com/4869/44783048580_5115996b61_o.jpg (https://flic.kr/p/2bejQ8f)