Passat 3C 2.0 BKP - White/blue smoke at 1800 rpm, misfires (Solution)

Here's a Passat that's producing extreme white/blue smoke when idling at 1700-2000 RPM. The engine speed fluctuates while the throttle position remains constant, and it smells like diesel. There's no visible smoke when driving (checked in the rearview mirror), but there's slight hesitation within that same RPM range. The customer claims this issue started after the work done on the PD injectors.
We've re-examined the power distribution elements and the seats, and everything looks good.

In MWB 13, everything looks good. Strangely, MWB 18 never changes from its value, and MWB 23 always reads between 0.20 and 0.21.

Hab jetzt noch den Druck der Tandempumpe gemessen, habe im LL 4 bar bei 2000 1/min 12bar und je höher die Drehzahl um so höher steigt der Druck, kann dann nicht mehr sagen wieviel weil sich der Zeiger schon im Kreis dreht. Hab jetzt eine andere Tandempumpe verbaut und mit dem Druck hat sich nichts geändert. Hab dann Rücklaufschlauch von der Tandempumpe abgezogen und in einen Behälter laufen lassen, Druck ist weiterhin so hoch und es kommt nach ca. 20sec ein viertel Liter Diesel am Rücklauf. WieIs that considered normal?
I suspect the misfiring and rough idling are caused by too much fuel.

I measured the compression using the tester, and there's a deviation of plus or minus 1 degree for each cylinder. In my opinion, the car is running normally.

The error from the LMM is because I didn't connect it during the pressure test.

In the log file LOG-01-004-018-023.CSV, the PD Status for cylinder 1 changes to "2", while the other three cylinders remain at zero.

Code:

Auszug des Meßwerteblocks 018,0,Status Piezoventile ; 000 = Fehlerfreie Regelung ; 002 = Steuerung bei Start

I'm not familiar with this.

Yes, you're right, I missed that, but it was only 0.19 seconds. But what are you implying? It jerked and sputtered the whole time at that RPM.

"By the way, after starting, it runs at approximately 650-700 RPM and takes about 1-2 seconds to settle down to its normal idle speed."

So, if it smells like unburnt diesel, then either it's getting through the injector nozzle or bypassing it.
I would almost suspect that the prechamber (nozzle to the combustion chamber) is leaking.

Possibly improperly installed (nozzle not centered in the cone), or tightening specifications not followed, or sealing rings damaged.

Too much fuel would result in black smoke. Blue/white smoke with a pungent diesel odor indicates "burnt" fuel due to low pressure or temperature. In this case, it seems that gasoline is unintentionally entering one of the cylinders. This confirms the cause suggested by the previous speaker. The issue becomes more noticeable at higher idle speeds, while under load, the exhaust temperature likely provides enough heat for after-combustion.
A hairline crack in the cylinder head near the piston seats would be another possibility.
hg
Herbert.

Here's the delayed feedback.

The mistake was that the parts department gave me the PD elements for the 170 hp engine, and I didn't check the part numbers (which was stupid of me).

Thank you for the feedback .

We were close, but it turned out badly anyway .

For posterity: Please always check the part numbers - not everything that looks the same is actually the same.

Hello,

I want to revive this thread again...

Quote:

The error was due to the fact that the parts department gave me the PD components for the 170 HP engine, and I didn't check the numbers. (Unfortunately)

...because it seems a bit strange to me.

To the best of my knowledge, the 125 kW/170 hp PD TDI engine uses Siemens piezo common rail injectors.
"Everyone else has Bosch MV PD components. How can that possibly work together?"
1. The plug fits.
2. The control is working correctly.
3. that the PDE fits mechanically.

Can someone please enlighten me about this?

At the "beginning," there were also 140HP TDIs with Siemens PPD, and I believe they were even in the Passat.

To the best of my knowledge, the 125 kW/170 hp PD TDI engine uses Siemens piezo common rail injectors.
"Everyone else has Bosch MV PD components. How can that possibly work together?"
1. The plug fits.
2. The control is working correctly.
3. that the PDE fits mechanically.

Both engines (e.g., manufactured in 2007), the BKP and the BMR, are equipped with PPDs. The difference is the index number; externally, they look identical.

BMR (170 hp) --> 03G 130 073 T and for BUZ.
BKP (140 hp) --> 03G 130 073 S and for BMA, BVE, BWV.

Hello Norbert,

One of my first jobs involved a 140hp TDI engine with a PPD (Pump Pressure Device), and at the time, it was necessary to open the engine control unit. I am 100% certain of that. The engine code should have been BKP.

All "PPD" injectors use Siemens piezo PD elements. You can also identify Bosch injectors (solenoid valves) by the different last digits of the engine control unit part numbers: 03G 906 018 xx = PPD, ... ... 021 xx or ... ... 016 xx = Bosch.

Best regards, Rainer.