TDI Smoking? Get Help Now!

Hello everyone.

Okay, I have a VW Vento TDI 1.9 with engine code 1Z. It has approximately 220,000 kilometers on the clock, and I had it chipped about 150,000 kilometers ago.

So far, everything has been running smoothly, except for two mass airflow sensors (apparently a common VW issue) that I had to replace. Lately, it's been making a rattling noise, and I don't know why. I once read an FAQ and suspected the mass airflow sensor, so I tried cleaning it, but it didn't help; the same symptoms persist.
'Sometimes, when I accelerate, I get normal and good acceleration. However, if I press the gas pedal too much, the engine starts to sputter.'
'But usually, I give it gas, and I notice it accelerates, but then it falls into a power dip, and it starts sputtering endlessly. I actually feel like too much fuel is getting in. I did a test and disconnected the hose from the crankcase ventilation system, and sure enough, the sputtering stopped, but the performance was also reduced.'
'I've also replaced all the vacuum hoses and pressure hoses, but that didn't help either. The air filter and fuel filter are all okay. I don't think the turbo is the problem. I suspect that the fuel injectors might be the issue, but I'm not sure if that would manifest in this way.'

I hope someone knows about this problem and can help me!

Regards,
zoom

The error memory is not displaying any errors!

Hi.

I think the AGR valve isn't closing properly. This means there's not enough oxygen in the combustion chamber, and that's causing it to smoke. I would suggest completely sealing the AGR system, by closing the connection between the valve and the intake manifold. Just blocking the hose won't do much if the valve itself is faulty. I made a small aluminum plate that looks like the gasket, but without the hole in the middle.

Good luck, Claus.

Hello zoom,

When the error memory is empty, it's a tricky situation. There are a thousand possible causes for black smoke. The only thing that's certain is that there's either too little air (oxygen) for complete combustion, or too much diesel fuel for the amount of air.
Given the high fuel consumption, I would first check (or have checked) the fuel injectors, as they might be leaking due to not sealing properly, or the spray pattern might be incorrect. Is the compression still okay? A lack of boost pressure could also be a problem (is the maximum pressure present? -> check the boost pressure control valve, and look for leaks in the intercooler or the hoses). Does the EGR valve close completely?

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"Find the repair manual for your engine and go through it step by step; you should be able to find the problem."