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

[poyta]

VW will replace the injectors for me but not the loom to the Injectors which had been first looked at (easily damaged when tested due to deterioration) by a non VW dealer mechanic. I am not 100% satisfied with this outcome, but close too. Just happy to get the car back after 5 weeks!

Hey sounds like a great outcome considering they just saved you over $6000 worth of injectors. You were lucky they covered those considering you're no longer under warranty. I'd be running out of that dealership screaming " start the car!! Start the car!!! " ikea humour

[ian]

When did they stop using the Piezo injectors in the Gt golf V, mine was built November 2008 Australian compliance Feb 2009
Engine No BMN142xxx, I asked at Barloworld but all i got was a blank stare,seems like Vw dealers are playing dumb over the injectors

[benough]

When did they stop using the Piezo injectors in the Gt golf V, mine was built November 2008 Australian compliance Feb 2009
Engine No BMN142xxx, I asked at Barloworld but all i got was a blank stare,seems like Vw dealers are playing dumb over the injectors

They have always used piezo injectors. It was a GT Sport TDI specific feature.

Just remember those people at the dealers are just sales people or a parts guy just trying to get a clean sheet. It's not there job to know about the finer technical details of the cars

[Greg Roles]

If you can find out, let me know, but I would guess ALL MKV GT's and Passats are in the potential fail category.

[Ozsko]

If there has been a change then the parts guys will know at what VIN it took place, they will not know when that vehicle was produced. No tech bulletin would give the date either just VIN numbers so the dealer personnel cannot be expected to know the date. I reckon that even VW (OZ) would not know when it happened.

[Ozram]

Hmmm, interesting thread.
I'm not suggesting any of you may be tempted to tinker with the high pressure fuel injection equipment, but thought I'd give a little warning about the dangers involved if you do.

The fuel pressure in common rail systems is immense. The flowjet machine that American Chopper uses to cut steel with water pressure runs at about 6-800 bar. Common rail injectors can operate in excess of 2000 bar!
Never loosen or re-tighten a high pressure injector pipe as a means of diagnosis, they are usually single use only pipes - I may be the next one to diagnose your vehicle and don't want a face full of high pressure fuel.
Voltage at the injectors is typically over 200.

And one you may not know..........
A piezo injector is different to the older style CR injector in that it needs two pulses of electrical current to operate not one. A pulse to turn it on and another to switch it off. If you were tempted to electrically disconnect a piezo injector to stop it operating, you may be unlucky enough to disconnect it in the *on* position.

Result - An injector pouring enough fuel into your cylinder to make it hydraulic lock.

Be careful with this stuff guys.

[kaanage]

Where did the CR injectors come into this thread?

So are you saying that the engine gets killed by the ECU, when it detects a Piezo solenoid injector failure, to prevent the possisbility of hydraulic lock. Then the cars just shutting down is more understandable but it seems like a very poor overall design if injector (or loom) failure REQUIRES the engine to shut down in order to prevent catastrophic damage.

And by "older CR injector", do you actually mean "older PD injector" which is closed purely by the return spring ?

[Ozram]

Just a timely reminder about the dangers of high pressure diesel systems. I still get many phone calls from people who think that cracking an injector pipe nut to look for fuel is a good method of diagnosing their broken down vehicle.

No, I'm saying that if you decided to unplug a piezo injector electrically, as a method of checking for a cylinder misfire you could detonate your engine.

No, not pump deuse. By older CR injector I mean solenoid controlled not piezo crystal controlled. The fuel pressure inside the injector is constant, it actually holds the needle in the closed position on the seat. The solenoid or piezo crystal stimulates a port opening that lifts the needle and opens the injector.

[kaanage]

So if the new CR injectors are also actuated using piezo electric crystal stacks, does that mean all the new high pressure CR engines are also prone to this failure mode?

[RobV]

The PD injector issue is obviously well known, would be interesting if any VW mechanic could give numbers to this problem. A friend of mine owned a business and had 2 passats in a row and both failed.(refused to get another one!) he warned me about the reliability issues before I bought my GT sport in 2008, I ignored his advice because mine was a newer model! So this has been around for a long time in Passats. But if the issues is a s big as it seems! (also Check UK web sites) why did VW persist with the same Injector/wiring kit????.
Are the replacements an improvement or the same parts????
Hope my car will be ready today, but my confidence has been shaken in VW reliability.