103kW/125kw TDI PD Piezo Siemens injector failure thread

Hey all,

There's growing evidence that the Siemens injectors fitted to the MKV 125kw engines are starting to fail across the board. Seems to affect the Passat mostly, but as this is basically a GT TDI engine with a counter shaft balancer, the injectors are the same. It seems to be the pizeo portion of the injector that fails, and VW are very aware of the problem and offering revised injectors at exchange with your old ones. I'd like to start a thread to both record the numbers of actual failures, and to inform of any options / fixes as they come to light. I'm doing a lot of research into it, as heck, mine could go at any time, and I'm wondering if I even bother with extended warranty given how modded my engine is starting to look, let alone what it'll look like this year when the big stuff finally happens.

Here's the first of a few interesting articles I've found, but across the world, there are people from Skoda, VW, Seat and even Audi up in arms about the issue. No doubt aftermarket injectors will come, and given the cost VW will no doubt charge, it's the way I'd go. At this stage all I've been able to find is they cost $400ish pound EACH in the UK, love to know what the going price is here.

https://sites.google.com/site/1810ma...iezo-injectors

Also interested if anyone can tell me why the swapout with warranty cars seems to also include the wiring harness - is it different, or just worth doing while you're in there?

One of many forums reporting on the problem. The GREAt news is there's a link to a UK company that can repair the Siemens. I've sent them an e-mail and will let you know what they say.

UKpassats.co.uk • View topic - Faulty diesel injector?

and the company link....

AP Diesels Ltd - Home

According to the ukpassats link they may be going to ground when they fail - Depending on the voltage/current/wire guage, etc, going to ground may be damaging the wiring, hence swapping it out. It's crazy they are that expensive though and i'm sure it's only a matter of time before they find a way to retrofit different injectors...

My 2c.

https://sites.google.com/site/1810ma...iezo-injectors

thats a great link transporter, thanks!

desertstorm linked to it in the thread linked in the 2nd post by CogDoc.

One of the Passat owners, here, with a 103kW TDi posted that he also had the same failure, though, and I thought those didn't use the piezo-electric controlled injectors

LOL, I completely overlooked that Greg already posted that link. Don't worry Greg, I'll clean it up. :)

mine failed 103kw tdi I was of the understanding the injectors were the same for the 103kw and 125kw PD's..

Nope they ate different, with the supposedly notorious pizeo part being a 125 thing, may have become common at some stage during lifecycle though. Very interesting if 'normal' 103 injectors are dying too, I thought they were quite reliable?

The more links and info, the better Miro, it's going to take a combined effort to solve this!

for the PD versions they both use same injectors, however the 125kw uses a higher pressure, also differences in the ECU and turbo? and the 125kw has the DPF. From wiki and other links they are otherwise the same.

ere is the difference between the 2 TDI engines - the outputs vary within each of the specifcations depending on ECU. The new 2.0 TDI as far as I know, does not have a Variable Geometry Turbo (VGT). This engine is being phased out over the next few years, in favour of an all new design, with the Pump-Dusse injection system being replaced with a Common Rail injections system.

2.0 TDI with 103 kW: 209 kph is the top speed of the 103 kW / 140 bhp (at 4,000 rpm) Passat 2.0 TDI. The four-cylinder engine develops a maximum torque of 320 Newton metres as low as 1,800 rpm, and takes just 9.8 seconds for an easy 0-100 kph sprint before reaching the top speed of 209 kph. Average consumption: 5.9 litres. This TDI performance level can be combined with a diesel particle filter.

Numerous details were modified in order to facilitate the use of an optional, additive-free diesel particle filter in the 2.0 TDI. Some examples: in order to allow the DPF to be mounted as close to the engine as possible, the position of the exhaust turbocharger was changed. The pressure with which the pump-jet element injects fuel into the slightly modified combustion chambers was also increased to as much as 2,400 bar. In addition to this, the pumping characteristic of the pump-jet was modified to allow additional injections for the thermal regeneration of the filter or other reasons. Engineers concurrently succeeded in further reducing the oil consumption, another measure to increase the efficiency of the DPF. The diesel particle filter is maintenance-free, and forms a modular unit with the oxidation catalytic converter.

2.0 TDI with 125 kW: The second 2.0 TDI, fitted with highly innovative piezo pump-jet high pressure injection and a compensator shaft, is a completely new design. This very quiet, four-valve TDI has an output of 125 kW / 170 bhp (4,200 rpm), develops a torque of 350 Newton metres (1,800-2,500 rpm), and accelerates the saloon to 100 kph in just 8.7 seconds. The top speed is 223 kph. Here, too, the average fuel consumption is low, at 6.1 litres over 100 kilometres.

Technically, the 125-kW TDI, with its switched induction manifold for turbulence control, is based on its 103-kW equivalent without diesel particle filter. This cultivated engine is the world's first piezo pump-jet TDI. Further technical features are two compensator shafts (reducing secondary vibrations by up to 80 percent), a maintenance*free diesel particle filter, and an injection pressure of up to 2,200 bar. The specific power of the 2.0 TDI, at 62.5 kW per litre, is a new best. Although the new TDI has power and convenience characteristics that come very close to those of a five- or six*cylinder turbo-diesel, the consumption and emission figures are in the low four-cylinder range.

Technologically, a central factor in the achievement of high power and convenience values together with low consumption is the use of the newly developed piezo pump-jet elements. Using one of the piezo actuators to control the high-pressure valve of the pump-jet permits:

· -very high injection pressure, and thus low emission and optimum specific power.

· -ideal hydraulic efficiency because of the very small high*pressure volume.

· -ideal injection process.

· -very precise, low-volume pre-injection at a low pressure level.

· -flexibly controlled pre- and post-injection and injection intervals.

· -low injection noise.

A further innovation in the TDI is the use of a newly developed compensator-shaft module. The term "module" is easy to explain: the two counter-rotating compensator shafts (turning at twice the engine revs), together with the oil pump, form a separate module located under the cylinder crankcase. The compensator shafts noticeably reduce the amount of vibration that is transmitted to the bodywork.

Aren't the Piezo pump-jets the newer injectors that are causing the problems? (last gasp for the PD before surcumbing to CR)

Quote:

---

Originally Posted by Greg Roles

No doubt aftermarket injectors will come, and given the cost VW will no doubt charge, it's the way I'd go. At this stage all I've been able to find is they cost $400ish pound EACH in the UK, love to know what the going price is here.

---

Thats scary - especially considering my warranty has just finished.

Is this from Wikipedia, because if it is, it's got a LOT of mistakes, when I have more time tonight I'll post up the facts.

Quote:

---

Originally Posted by OilBurna

for the PD versions they both use same injectors, however the 125kw uses a higher pressure, also differences in the ECU and turbo? and the 125kw has the DPF. From wiki and other links they are otherwise the same.

ere is the difference between the 2 TDI engines - the outputs vary within each of the specifcations depending on ECU. The new 2.0 TDI as far as I know, does not have a Variable Geometry Turbo (VGT). This engine is being phased out over the next few years, in favour of an all new design, with the Pump-Dusse injection system being replaced with a Common Rail injections system.

2.0 TDI with 103 kW: 209 kph is the top speed of the 103 kW / 140 bhp (at 4,000 rpm) Passat 2.0 TDI. The four-cylinder engine develops a maximum torque of 320 Newton metres as low as 1,800 rpm, and takes just 9.8 seconds for an easy 0-100 kph sprint before reaching the top speed of 209 kph. Average consumption: 5.9 litres. This TDI performance level can be combined with a diesel particle filter.

Numerous details were modified in order to facilitate the use of an optional, additive-free diesel particle filter in the 2.0 TDI. Some examples: in order to allow the DPF to be mounted as close to the engine as possible, the position of the exhaust turbocharger was changed. The pressure with which the pump-jet element injects fuel into the slightly modified combustion chambers was also increased to as much as 2,400 bar. In addition to this, the pumping characteristic of the pump-jet was modified to allow additional injections for the thermal regeneration of the filter or other reasons. Engineers concurrently succeeded in further reducing the oil consumption, another measure to increase the efficiency of the DPF. The diesel particle filter is maintenance-free, and forms a modular unit with the oxidation catalytic converter.

2.0 TDI with 125 kW: The second 2.0 TDI, fitted with highly innovative piezo pump-jet high pressure injection and a compensator shaft, is a completely new design. This very quiet, four-valve TDI has an output of 125 kW / 170 bhp (4,200 rpm), develops a torque of 350 Newton metres (1,800-2,500 rpm), and accelerates the saloon to 100 kph in just 8.7 seconds. The top speed is 223 kph. Here, too, the average fuel consumption is low, at 6.1 litres over 100 kilometres.

Technically, the 125-kW TDI, with its switched induction manifold for turbulence control, is based on its 103-kW equivalent without diesel particle filter. This cultivated engine is the world's first piezo pump-jet TDI. Further technical features are two compensator shafts (reducing secondary vibrations by up to 80 percent), a maintenance*free diesel particle filter, and an injection pressure of up to 2,200 bar. The specific power of the 2.0 TDI, at 62.5 kW per litre, is a new best. Although the new TDI has power and convenience characteristics that come very close to those of a five- or six*cylinder turbo-diesel, the consumption and emission figures are in the low four-cylinder range.

Technologically, a central factor in the achievement of high power and convenience values together with low consumption is the use of the newly developed piezo pump-jet elements. Using one of the piezo actuators to control the high-pressure valve of the pump-jet permits:

· -very high injection pressure, and thus low emission and optimum specific power.

· -ideal hydraulic efficiency because of the very small high*pressure volume.

· -ideal injection process.

· -very precise, low-volume pre-injection at a low pressure level.

· -flexibly controlled pre- and post-injection and injection intervals.

· -low injection noise.

A further innovation in the TDI is the use of a newly developed compensator-shaft module. The term "module" is easy to explain: the two counter-rotating compensator shafts (turning at twice the engine revs), together with the oil pump, form a separate module located under the cylinder crankcase. The compensator shafts noticeably reduce the amount of vibration that is transmitted to the bodywork.

---

Hi Greg,
Try $1500 per injector, and its the wiring loom that starts it all. The insulation hardens, cracks and falls apart, then shorts the injectors to ground, and hey prestor, $7500 worth of headache.
Rob V

mine was just over $4,000 to replace including loom.

Quote:

---

Originally Posted by RobV

Hi Greg,
Try $1500 per injector, and its the wiring loom that starts it all. The insulation hardens, cracks and falls apart, then shorts the injectors to ground, and hey prestor, $7500 worth of headache.
Rob V

---

Wow now that's both scary, yet interesting. So perhaps if working looms could be better protected from oil and heat, the problem might be minimised....but it would seem both loom and injectors can fail as both are usually replaced at once on warranty claims.

So, I gather just the loom itself is over $1,000 fitted? I was thinking maybe it would be "cheap" insurance to replace the loom, but of course most units aren't going to experience this fault (I assume), so it may not be $ well spent?

Greg,

Have you been able to find out if this is fixed in new cars ? Looks like I'll be ordering mine Monday.

Quote:

---

Originally Posted by Greg Roles

Wow now that's both scary, yet interesting. So perhaps if working looms could be better protected from oil and heat, the problem might be minimised....but it would seem both loom and injectors can fail as both are usually replaced at once on warranty claims.

---

I remember seeing the wiring loom failure on 103TDI Golfs with non-piezo injectors. Also loose injectors being reported on Dieselpower.cz for some time. Usual fix is repair the thread in the cylinder head and seal in injector. Without knowing the full history of the failed engine (car) it will be hard to get at the bottom of what cause the failure as many of causes I read are just speculations (IMO).

Quote:

---

Originally Posted by RobV

Hi Greg,
Try $1500 per injector, and its the wiring loom that starts it all. The insulation hardens, cracks and falls apart, then shorts the injectors to ground, and hey prestor, $7500 worth of headache.
Rob V

---

ive gotten a few of these in at work, the problem isn't the loom breaking its the injector shorting out, thats why when it happens the car will not run at all because it shorts the whole circut.

this doesn't damage any of the other injectors or the loom, the main reason (not only reason) vw will change the loom is because the plugs shatter when removing them (sometimes not, no loom required). To replace them you need a tool kit to get them out (which i have) it includes other peices like dial indicator mount so that you can set up the clearances of the rockers.

To sum up, if it happens to your car you can replace just the one injector, ive only seen number 2 fail so far, but ive only done 2 cars.
No doubt the other might fail but i think its worth the $4500 difference to hope for the best.

I am surprised that the injector replacement is not a dealer only job. On one brand I know of anyone can replace the injectors but until they are coded to the car the injector will not work and that is a dealer only job.

Quote:

---

Originally Posted by Ozsko

I am surprised that the injector replacement is not a dealer only job. On one brand I know of anyone can replace the injectors but until they are coded to the car the injector will not work and that is a dealer only job.

---

Yeah, Toyota tried many things to fight aftermarket and it didn't work. :)

It works with Mazda, no dealer coding = no go, ask those who have tried to get around it. Panel beaters for instance are finding that after they replace a power steering pump on a Mazda they have to get a dealer to code it also. It surprises me as I said that VW have not gone down this path. Also any one who fiddles with a common rail diesel fuel system had better know what they are doing due to the extremely high fuel rail pressures, it is a job not to be taken lightly. Don't believe it? it's your problem if you get injured.

I had one of my injectors fail under warranty but as far as I know the loom stayed.

Quote:

---

Originally Posted by PeDiES

ive gotten a few of these in at work, the problem isn't the loom breaking its the injector shorting out, thats why when it happens the car will not run at all because it shorts the whole circut.

this doesn't damage any of the other injectors or the loom, the main reason (not only reason) vw will change the loom is because the plugs shatter when removing them (sometimes not, no loom required). To replace them you need a tool kit to get them out (which i have) it includes other peices like dial indicator mount so that you can set up the clearances of the rockers.

To sum up, if it happens to your car you can replace just the one injector, ive only seen number 2 fail so far, but ive only done 2 cars.
No doubt the other might fail but i think its worth the $4500 difference to hope for the best.

---

So what are the symptoms when an injector fails? Is it catastrophic or does your car just start running on 3 cylinders?

Mine just stopped and wouldn't start again. Zero warning.

Maybe you should get onto that used car warranty Jarred?

Quote:

---

Originally Posted by benough

Mine just stopped and wouldn't start again. Zero warning.

Maybe you should get onto that used car warranty Jarred?

---

most used car warrantys will only cover part cost, hardly worth it

Quote:

---

Originally Posted by PeDiES

most used car warrantys will only cover part cost, hardly worth it

---

Yep thats why I'm not bothering.. Whats the deal with VW offering exchanges? I would assume its not free, but I think I read somewhere about them selling the refurbished ones?

they will sell you an injector with a core charge which they then return when you return the old injector. The injector cost is there the whole time its just the core charge that comes and goes. My guess is they go back to siemens in mass then the cycle continues

Be great to get a firm price on that, at this stage it seems going OS is FAR cheaper.....

mine stalled today, still at the service centre, i guess i'll find out tomorrow, but this injector failure seems to be the case...

will post update as soon as i find out..

Injector 2 and 4 have failed on mine...wiring loom was repaced when injector 4 failed first....2 died on Tuesday no warning...tow truck job.

Jetta or Golf?

I have a Golf GT... I just spoke to the dealer it looks like they will be replacing all the injectors

Still under warranty I hope? Bloody hell, I feel like I'm driving a tick time bomb now. Any chance this could become a recall issue???

I asked the VW dealer I brought my TDI sport from if there were any recalls, none are registered according to them. If I was driving a Passat TDI, I would also be very concerned, I have just heard from a friend who's company had 2 in a row, both had major reliability problems. investigate the extended warranty, might just be needed.

I know how you feel!

The sheer number worldwide makes me wonder why there isn't a recall, but hey, I'll do my part to see what's possible...

I've always wondered who initiates a recall? The manufacturer is obviously going to have stats on the number of vehicles affected, but if they decide to do nothing (and if it isn't a safety issue, then they may not be interested in issuing a recall) , how does a consumer group or consumers find out to put pressure on the manufacturer to do a recall if it is warranted?

Quote:

---

Originally Posted by poyta

Still under warranty I hope? Bloody hell, I feel like I'm driving a tick time bomb now. Any chance this could become a recall issue???

---

Yes still under warranty...but I think Volkswagen should recall and replace units with a a different injector. I am definitly taking out extended warranty....

Quote:

---

Originally Posted by Hilly

(and if it isn't a safety issue, then they may not be interested in issuing a recall) , how does a consumer group or consumers find out to put pressure on the manufacturer to do a recall if it is warranted?

---

It will generally only happen under a class action lawsuit :(

If we could document instances where cars had been involved in accidents (eg rear ended when the engine cut out in the fast lane of a highway/freeway) then there would be a strong case of the issue endangering lives (we know it is dangerous but who knows when lawyers get involved:facepalm:)