1.6 TDI VDO Injector failure root cause analysis

[eva69]

I’m three down in 6 months and one likely to go soon, even though the four were new when I bought it in Nov from a garage. Confirmed by my own mechanic too.

Can I ask what you disclosed in your sales pitch? Should I try part exchange at a garage rather than private? I feel crap selling it on.

Thanks in advance.

[ransomz0]

I took mine to we buy and car and took the pain. I didn't want to sell it privately and the trade in price was about the same.

[ransomz0]

how the manufacturer of this engine and injectors have got away with such a shoddy product is beyond me. Can you imagine how much misery the owners have gone through whilst they rake in the cash for the replacement injectors..... I'm not bitter :-)

[TheSheriff]

Hello guys, special thanks to BenT and Engineer, and everyone on enlightening me. I have collected quiet some of these in 8 years as a diesel tech from Denmark. I am able to repair the mechanical part of the injectors and calibrate it on my Komtest diesel bench. But the electric part I have never really tried to repair, but you guys have woken my curiosity since this problem is a common issue.

BenT, can I request a video of you dismantling the solenoid cap and how you strip the silicone step by step. You said you had read a news paper stating you could regenerate the electric plate and i would like to try to make 1 good from 2 bad.

If i solve this i will send you a few extras to you guys

[BenT]

Hey there, I don't see any way that the piezo actuator could be repaired once fried (i.e. once dielectric breakdown has occurred). The only way to extract the piezo stack from the cartridge is to destroy said cartridge, so I'm afraid that replacement of the complete unit is the only option. I used a hacksaw and a lot of effort to disassemble the cartridge. An angle grinder would also do it.

From the (academic) paper I read, the crystal stacks do gradually deteriorate with repeated expansions and contractions and cracks can form in the material. I'd guess this eventually leads to dielectric breakdown and melting of the material. I think the authors of the paper used pulse signals to repair the material, but how this could work I'm not sure.

Unfortunately, my only take away from all of this is that there's likely nothing we can do as owners to avoid the issue so best to carry a spare and some tools with us, swap the engine or sell your soul to Georgia Meloni.

I was thinking of doing a video of the disassembly though, so I'll try to get around to it!

[Critical1]

Done all 4 with brand new S type no problems for years now

Where did you purchase the new S type injectors? I'm looking for reliable places that sell them and get confused with all of the product codes. The ones from PFJones for example have the code A2C9626040080 but say they cross reference with the 'B' code the 'S' code and also the 'SX' code.

[Engineer Bob]

Having got so p***ed-off with replacing injectors, 12 in total over 11 years, on my 1.6 CAYD Caddy Maxi Life (14 plate, 47k miles) and my mental state in waiting for the next failure to occur, I finally made the decision to sell the vehicle to We Buy Any Motor Caravan since it had been converted to a camper van. I had all of the injectors replaced (purchased from P F Jones) before the sale to at least give the new owner a fresh start.

I really enjoyed driving my Caddy when it was functioning correctly and the camper van conversion did exactly what my wife and I wanted. The big problem was the injector failures, the cost of replacement and the potential danger we were placed in every time that failures happened. I will never trust VW or any of its associated companies again and feel that there was a big cover-up regarding the injector failure with absolutely no support being provided once the warranty ran out. I didn't even make a claim following the 'Diesel Gate' fiasco since I had not purchased the vehicle for its economy.

I have been told by numerous motor engineers that we were using our Caddy incorrectly, it was designed for continuous use with relatively long runs and not the occasional usage (approx. once a week over a 12 month period) that we were doing. I wish that we had known this when the vehicle was sold to us by a supposedly reliable VW appointed dealer, who was made fully aware of what our usage would be.

The only thing that I have to do now is to dispose of the 3rd row seats that were removed during the camper van conversion, anybody interested?

[STP]

I have a 2015 CAYD engine, 1.6 with S injectors, checked the date codes on top and all are 2015. I know the company who owned the van from new, it was a plant equipment rental outfit and the van did 108k before I bought it. I also know the garage manager who supplied the van to them, and serviced it the entire time they had it before I bought it in January this year, and so I got the full service history from him with the van, as it was traded back in when they got a new one. It's now on 114k, I always use BP Ultimate diesel, but mostly short journeys every day as I work only 5 miles from home. It does get a bit more miles at the weekends. I always drive until a regen is completely done, I know when it's happening and never park up while it's ongoing.

To my knowledge it has never had a single injector replaced.

My question is, have the people with lots of failures, fitted an engine cover by any chance? I haven't as I know they make the injectors run very hot. Just wondering if people who had failures can chip in and comment on that question.

VW stopped fitting them to the vans at some point, and mine is a run-out model with all the toys, I wonder if that's why they stopped fitting the covers. Since mine was a Startline from new but got VW hands free, cruise control, electric windows, towbar, Bluetooth radio etc and the Highline dash clocks with full MFD display so they could have plonked a cover on but didn't.

Makes me wonder about the covers being fitted by owners, and the injectors failing later.

[Engineer Bob]

Hi STP,
No, I never fitted an engine cover, looked into doing so since the fixings were already on the engine but never bothered. I purchased the Caddy 7 months after it was first registered so I am pretty confident that one had never been fitted.

It would have been great to have found the reason for so many injector failures, however the problem goes away for me since selling my Caddy!

[STP]

Yeah I am sure they revised the design on the vehicles from 2015 onwards and have a lot less (if any) failures that I have seen online. The early Siemens injectors on the Ford engines had the same issues, it wasn't just VW. So I expect eventually Siemens listened and fixed the problem.

[joebloggs]

A lot of effort went into that - I too suffered an injector failure recently and was half thinking about opening it up. Now I dont need too - thank you!

[Smithersg204]

Great read.

Amazing detail and a great insight. Thank you

[recvancad]

Thanks Giddy, the resistor is indeed intact and had the same resistance as a known good injector, plus all four of those currently in my van. Unfortunately, my multimeter is temperamental so couldn't get an actual reading! All I know is that, at any moment in time, all 5 good injectors and the resistor from the disassembled one were showing the same, +- 10 k Ohms. I sadly don't know the fault code. Here's a link to an article for anyone feeling geeky:

http://www.combustion-engines.eu/Method ... 6,0,2.html

Apparently, micro cracks can form in the stack causing some short circuiting. Maybe we're all doomed after all

I've been very interested reading up on this issue, I feel you have the best understanding of the issue that I've been able to find online. one thing I would note is that a lot of cases I've heard about occurred while the vehicle was either driving at 70+, or going uphill. Could this indicate the issue is likely to do with engine temps, or engine pressure? I also think the theory about the dpf regeneration attempts frying the injector material is a strong one.

Thanks

[BenT]

If only I knew more... I don't think it would change anything though - there are no alternative aftermarket injectors for these engines. There's so much misinformation about which clouds the water too, unfortunately.

All I do know is that in the two injectors I've disassembled, the piezo crystal wafers had disintegrated in exactly the same place in the stack on each injector, with a metallic material seemingly penetrating through the wafers (melted electrode material maybe?). This is how I imagine dielectric breakdown looking in a capacitor.

So, either there's been a significant voltage spike causing current flow, or the electrodes have got too close together. The latter would happen if the piezo material started cracking up, or if the stack was over-compressed. Overcompression could occur if the stack expanded too much (high temperature perhaps?) or if something further down in the injector jammed, preventing the stack from expanding as intended. I didn't disassemble the lower part of my failed injectors, so there could be answers there...

In any case, my first injector went at 70 mph going up a slight incline on a freezing day in December. I'd no engine cover. The second one to fail just refused to fire up for a couple of seconds on cold starts for a few weeks so I replaced it prophylactically. The third failed on a short run (only 1 mile into the journey), going downhill at 40 mph with my foot barely on the accelerator. This was a 2017 03L130277S injector. Yes, they fail too.

Given that Volvo, Ford, Peugeot/Citroen, Renault/Nissan, Land Rover and VAG all use these injectors and all have problems, it seems inescapable. Out of all of these manufacturers, there are far more complaints about VAG injector failures on forums than any other.. maybe because VAG owners expect better, or we like to whinge, or maybe they do fail more often.

I did read that, as part of the emissions fix, VAG introduced more injection cycles per stroke on cold running. More cycles means more opportunity for cracks to form in the piezo material and for other issues to occur. So, maybe those doing lots of short runs might run into problems sooner than those doing mainly longer runs.

As before, the only advice I could give to anyone is to carry a spare injector and the tools to replace one by the roadside. Stochastic failure seems to be inherent in their design, unfortunately, so maybe just in this case cure is better than prevention.

[Engineer Bob]

Hi Ben T, you have put into words what I have been thinking for a long time about the failure of the injectors. I highly suspect that the extra cycles introduced (I understand that the cycles were doubled) during the emissions fix contributed to the failure. Doubling the cycles logically halves the expected life of the component. My first failure occurred just after the emissions fix was performed by the VW garage that I was using, which had also sold me the vehicle. Before the 3 year warranty period had run out I had another failure and VW instructed the garage to also replace the other 2 injectors. In hindsight this tells me that VW were fully aware of the problem and were doing a cover up. In all I think that I had 12 failed injectors replaced during my 11 years of ownership. Needless to say I do not have a good word for VW, especially their customer support.