1.6 TDI VDO Injector failure root cause analysis

[HonkL]

Hi everyone, I’d like to share my experience. I have a VW Caddy 1.6 TDI 55 kW, and I’m from the Czech Republic.

I had a complete injector replacement (Bosch) done at 130 000 km back in 2021 — the total cost was around 66 000 CZK (around 3000 USD).

Today, after driving about 40 km on the highway, the car suddenly went into limp mode.
My first thought was that it’s the injectors again — and unfortunately, it turned out to be true.
Injector number 4 failed.
According to the previous service records, it was a original Bosch injector, but it only lasted about 20 000 km.

The car’s mileage is now around 155 000 km. I don’t drive it very often these days.

I still don’t know how to handle this issue better or how to prevent it. From what I’ve learned, this engine seems to be quite prone to injector failures.

Tomorrow I have to tow it to the mechanic. Any advice on which injectors are good? TNX

[STP]

@HonkL, what year is your Caddy? Also it can't have Bosch injectors, they are all Siemens. Bosch don't make injectors for the VW TDi engines. The B or S at the end is just a manufacturing code. They are still Siemens.

[Javito]

Is it just me thinking there must be something else killing the injectors? I mean 40km... Either you have extremely bad luck or the problem is somewhere else.

[STP]

I'm thinking the same thing. The Piezo stack still has to move a mechanical needle to inject fuel, it must be some sticking in the mechanism to cause the Piezo stack to crack while trying to move the injection needle. This is why they are called injectors. Like a syringe. The Piezo stack pulls the needle up to let rail pressure fuel pass through the injector nozzle.

I think some mechanical issue is jamming the needle preventing it from lifting easily and the Piezo stack deforms when trying to lift it.

[Engineer Bob]

I still strongly believe that the failures are electrical. The 2 piezoelectric modules that I stripped and examined displayed classic electric flashover on the piezo stack. I'm not sure that I could link this to 'sticking' within the mechanical mechanism.
The bottom line is that the manufacturers (both of the component and vehicle) have not addressed the problem to find a solution and since things have moved on there is no pressure on them to do so. They are very happy to receive the extortionate amount of money that is charged for replacements.

[Javito]

I still strongly believe that the failures are electrical. The 2 piezoelectric modules that I stripped and examined displayed classic electric flashover on the piezo stack. I'm not sure that I could link this to 'sticking' within the mechanical mechanism.
The bottom line is that the manufacturers (both of the component and vehicle) have not addressed the problem to find a solution and since things have moved on there is no pressure on them to do so. They are very happy to receive the extortionate amount of money that is charged for replacements.

I agree. And if my injectors failed repeatedly I think I would consider replacing the ECU and loom rather than just the dead injector/s.

And regarding manufacturers, I think the equation is pretty simple. As long as the fix is more expensive than the odd lawsuit they might get (if they do get any) nothings going to happen.

[HonkL]

@HonkL, what year is your Caddy? Also it can't have Bosch injectors, they are all Siemens. Bosch don't make injectors for the VW TDi engines. The B or S at the end is just a manufacturing code. They are still Siemens.

Sorry i made misstake .. It is SIEMENS .. Common Rail SIEMENS/VDO CRI 5WS40539.

Right now is car in Garage.. Waiting for test all injectors. Results will be after new year.. Everybody have holidays until new year..

[northflash]

Hey guys, reviving this old thread in the hopes of some advice!

Wicked initial analysis; it makes a lot of sense too, as I noticed higher RPM idling at a red light on the day my injector went, which may give more evidence to the thesis that regens are the cause. Up until now my injectors have been very well behaved, with none going in my 5 year ownership and I've covered over 60k miles with a considerable amount on motorways.

I'm now in the process of trying to replace it and not sure which injector to turn to. My local mechanic, who I've used for 6+ years and I trust says he fits Continental ones once a month or so and seems to have some success with them. He didn't give me a part number but says that they replace the piezo inside and everything. £262 + Vat for that one. Up until now I thought I was going to go with a Siemans brand new, part no A2C9626040080NEW, can be found at PF Jones for £346.80.

Has anyone had experience with either one and able to offer some advice? I'm pretty strapped for cash tbh but I've never cheaped out when it comes to service and parts on my van and won't now if there's a measurable difference.

Thanks in advance!

[Gary.8]

The Pf Jones injectors are Continental one's

[Engineer Bob]

Although I have moved on from this problem by selling my Caddy (and improved my mental health !), I would not trust an injector that had the piezo actuator replaced. The research that I did regarding the manufacturer of the injectors fitted to the 1.6 TDI engine (CAYD?) found the the only OEM of the injectors was Continental.