1.6 TDI VDO Injector failure root cause analysis

[BenT]

Yes as I live on isle of man. Longest runs being 12miles a slow speeds. Never a good time for it to go but 2 at once is a nightmate and worried the other two will go soon or was I just unlucky?!

Thanks for posting back! Two failing at once doesn't seem likely to be due to gradual mechanical breakdown, more likely something that happened that day. You could test the remaining injectors for capacitance and resistance which would indicate if they're starting to break down inside, I'd guess that once short circuits start within the stack they overheat and melt pretty quickly, i.e. next time an extended DPF regeneration occurs, perhaps. Commiserations again, anyway. All this surmising doesn't really help to fix the problem at hand

[Doc]

A VW part number ending in X is a refurbished or remanufactured part.
The injectors for these engines only had B or S suffix out of the factory. If you see SX its because someone has got new injectors under warranty and their originals have been tested and send back out.

[Engineer Bob]

@BenT
Thanks BenT, your failure analysis was very interesting and informative, it takes me back to when I used to do failure analysis on semi-conductor devices!
I will certainly use your analysis if the need arises. So far I have contacted the Motor Ombudsman and BBC Watchdog about the unreliability issues that seem to be associated with the injectors used in the VW 1.6 TDI engine. I just wish that I could obtain supporting evidence that shows that there is a disproportionate number of failures of the injectors used in the 1.6 TDI engine vs those used in other VW diesel engines. As I said before, any supporting information regarding injector failure experiences would be welcome from anyone on this forum.

@ransomz0
Thanks for your response. Please let me know what your experiences have been, everything that adds to my own experiences will help in supporting my quest with VW to acknowledge that there is a problem.

[BenT]

Quick question to anyone who has suffered this failure, if I may, please: did you notice any symptoms in the days/weeks leading up to the failure, or was everything fine until just before it wasn't? For example, was there any rough running, loss of power, hesitation or other random behaviour leading up to the failure? Thanks in advance!

[DW2207]

Mine just went into full limp mode whilst in Lane 3 overtaking two lanes of lorry.
Luckily I was carrying enough speed to carry out the task and drift slowly over to the hard shoulder.
No warnings, nothing.
I now keep a spare one in the van along with a few tools to replace should it happen again. Look at this part now as a spark plug that will need changing every know and again.
1st world problems

Sent from my SM-G981B using Tapatalk

[BenT]

Thanks for posting back! Scary stuff... It's the lack of warning that worries me more than anything. But, it also makes me think it's likely not a gradual wear and tear thing, but a spontaneous failure. I'd thought it might be DPF-related, but yours should have been having an easy time by the sound of it!

[SRAutoSolutions]

Absolutely loving this thread, i hope theres more of these covering a few other known issues!

[Tecwyn]

Excellent breakdown of these injectors have to be 1 of the worse out there even the modified S are just as bad by the sounds of things

[AndyBa]

The 2011 1.6 we have had 2 failed injectors. One minute it would run fine, the next it would run rough/go into limp mode.
I know someone who works for a Skoda dealer and I was surprised he didn't say he was aware of an issue. Bearing in mind the 1.6TDI engine is used in many VAG models.
It's a shame the injectors are so "B" expensive. Thanks to this forum recommending TT Automotive in Loughborough we got 2 new Continental ones at a "good" price and very quick delivery. The van is now covered with AA garage cover too.

[Gazawoody]

I note previous comments on this thread with interest. I own a wheel chair accessible Caddy Life 1.6tdi 62 reg auto. I do not drive because of my disability. The vehicle has only done 10k plus but is used daily on short runs and occasional motorway journeys of 80 miles. It has now consumed 5 injectors, the most recent on 19/12/21 when accelerating on to a motorway. Very dangerous as van went into limp mode when in lane 2. There have been 3 similar incidents on motorways.
First 3 injectors replacements were refunded by VW as a good will gesture but since then they don’t want to know. Prior to latest incident I noticed that the DPF was regenerating regularly on short runs round town with idle speed of 1000 rpm and fan cutting in when switched off. Is this the cause along with low mileage and short runs.
I am now faced with another hefty bill with the probability of another sequence of injector failures. I have no confidence in this vehicle, but selling in not an option because of my disability.
I have also heard that supermarket fuel and fuel filter can be a contributory factor. Where do I go from here, bite the bullet and also get AA garage cover? Anyone got any useful suggestions.

[Engineer Bob]

I sympathise completely with Gazawoody. Since my last post I have had yet another injector failure on 15th December at 41K miles, this bringing the total to 6. The failure occurred yet again with minimal warning on the busy A30. Recovery and repair was performed by a local garage (not VW franchised) using approved parts at just over half the price previously charged by a VW approved garage. The proprietor of the garage told me that that, in his experience, failures of these injectors fitted to both VW and Ford vehicles was very common. The number of these failures is not acceptable, My VW Caddy is the most unreliable vehicle that I have ever owned and the most expensive to maintain, if it wasn't for the fact that I had spent a fair bit of money converting it to a mini-camper, and that we thoroughly enjoy using it, I would get rid of it without hesitation. I purchased the vehicle because of the perceived good reliability of VW as a manufacturer, what a mistake!

Having contacted VW and the Motor Ombudsman both have said that since there is no warranty issue they are not interested in the problem.

Does anybody have an opinion as to whether it is worth considering having the alterations that were made to the engine when the NOx modification was carried out, removed and reverted to its original configuration? Comments would be very welcome.

[EmmmBeee]

I have just had EGR valve go, quickly followed by injector 1 going on both occasions taking van into limp mode on motorway with no warning signs. Now reluctant to drive or driving feeling a tad stressed and avoiding smart motorways for sure. What can actually be done to make the van a reliable drive or should I be looking for another vehicle?

[BenT]

Thanks to all for your posts and sorry to hear of the problems this is causing. A bit of an update...

Having pontificated about how my injectors have lasted 150,000 miles without fault, today, it happened. I was 300 miles from home (of course) on my return journey from holiday. I was doing a steady 70 mph in the left lane of the M5 and the engine was running faultlessly, until it wasn't. It just lost power instantly, the glow plug light started flashing, but I did manage to limp it at 50 mph until the next services came along (a bit scary!). I had a spare injector in the van which got me home, but I couldn't code it so it now sounds like a tractor

There was literally no warning at all. The DPF was NOT regenerating either, so that theory's out of the window. I'll be taking the injector apart soon to take a look inside.

I actually tested the injector resistances before I set out on my ill-fated journey. They were ALL the same as my spare, new injector. Whatever caused it to fail happened over the space of no more than 450 miles.

Suffice to say I have no confidence in the van whatsoever. As far as I'm concerned, this could happen any time, anyplace, anywhere (accelerating out of a junction, overtaking something, slip road, outside lane of motorway, in the middle of a funeral procession...). I might even nickname the van "Martini"...

So what do we do?

1) Sell it to someone else? Doesn't solve the problem, unless the buyer is a total b*stard Karma will be had
2) Carry a spare and change them as they go. £££ and inconvenient. And dangerous.
3) Replace the whole engine (again, £££). At least it shouldn't happen again
4) Swap a lovely Bosch engine management system (injectors, HPFP, ECU, MAF, MAP, commonrail + pipes and sensors) onto the engine from one of the 2.0 CR models and remap to account for the smaller displacement. Might be tricky, and still expensive.

Sorry to draw a blank, I'd really hoped there might be a way of stopping this from happening, but it seems to be random.

Whatever I end up doing, I will be keeping my rusty, squeaky, mouldy 2001 Octavia TDI for the forseeable. It just works.

[BenT]

Quick update - I've disassembled my injector which kindly failed yesterday. Please see pictures:

The stack (I was rough with it this time, hence the broken bits!):



Only one wafer had failed this time, again the third one down from the top. Only minimal damage, a crack in the corner:



This is a side-on view - the electrode plates are clearly visible as horizontal silver lines, the resulting short circuit from the crack blew a hole in the side of the wafer (the dark mark on the bottom right):



This failure was actually quite different to the last. It looks very much like the wafer has cracked at the corner, short circuited and gone bang. There's none of the internal wafer melting seen with the last injector. The last one had three affected wafers too.

Are there two modes of failure, perhaps? One being melting caused by extended DPF regenerations, another by random cracking through millions of injection cycles? This is the first failure to have occurred in 150,000 miles, whereas others have suffered multiple failures at much lower mileages.

I really do like the van. It's solid, drives nicely, comfortable, relatively nice to look at. And other than this, reliable! But the thought of it just letting go like this without warning really is off-putting. Good luck!

[Engineer Bob]

BenT
I really sympathise with you, this situation of the injector failures is beyond a joke and is potentially dangerous. I am now on my guard every time we go out in our Caddy (aka Geronimo) expecting another failure to occur. Your questions regarding keeping your Caddy are very similar to mine, what to do?
I am also wondering whether the failure is being caused by a random high voltage spike, I don't know how to investigate this and obtain meaningful answers.

I still feel strongly that even though the vehicles experiencing these injector failures are out of manufacturer's warranty there is obviously a design fault which I believe strongly VW should investigate and provide a solution. The injector design is not fit for purpose. The cost of replacement injectors is outrageous and just adds insult to injury irrespective of the mental anxiety in waiting for another failure to occur.

I am seriously wondering if I should change my injectors on a regular basis, possibly every 2 years. The injectors at positions 1 and 4 have been replaced within the last 2 months and therefore if they fail should be under warranty. However, injectors 2 and 3 were replaced in December 2018 so if another one is going to fail I would expect it to be one of those two.