As the title says, is it possible to do an actual passive regen on these engines? I've driven the car at speeds ranging from 100kmh to 190kmh, in different gears and it still wouldn't get hot enough. The only time when it actually goes above 420deg C is when I'm driving uphill and keeping it floored.

It’s not always down to what speed you’re driving at, more a case of how fast the engine is going.
Keeping in a low gear at say 80kph will work just fine.

To me it seems that the engine load is the biggest factor, but I might be wrong, that's why I've opened this topic. I've also tried 4th and 5th, keeping a steady 2500 rpm but wouldn't go higher than 330ish deg.

TDI's with a DSG can be taken for a drive and do regens and no extra load is happening, no low gear thrashing etc. 

But I'm talking about a passive regen. Not active ones. I've noticed that when engine is under heavy load, the temperature goes up without any post-injection fuel, and the soot starts going down. 

2 hours ago, BogdanB said:

But I'm talking about a passive regen. Not active ones. I've noticed that when engine is under heavy load, the temperature goes up without any post-injection fuel, and the soot starts going down. 

It’s like that in the beginning if the DPF is new/the while car is new. Brand new car owners start to notice passive DPF regens at 1000-1500miles. Then when car reaches 5-10k, it usually happens every 200-300 miles.

 

I can’t tell you exactly why this is happening like that, but when the DPF is new it takes a while it’s been clogged for the first time. 

The car is not new, but I did have the DPF manually cleaned. Maybe that is the cause?

5 minutes ago, BogdanB said:

The car is not new, but I did have the DPF manually cleaned. Maybe that is the cause?

Could be, yes. Can’t you for sure, but I drove brand new VW Caddy 2.0 TDI some time ago and didn’t notice a DPF regen in the first 1500-2000 miles. Even though it was doing mainly short trips and everyone who drove it was driving it as stolen  

Now it’s doing regens every 200-250 miles, it’s on ~30k miles.

Wait 2-3k miles and see is this the case. BTW was the car recoded after the DPF cleaning? Not sure is this necessary? You may want to find out more info about that, because DPF cleaning isn’t official VW procedure - once clogged, VW recommends unit replacement.

Edited 14 March, 20215 yr by fr1nklyn

Yes, the oil ash value has been reset. 

And honestly, I think it's a total scam and waste of materials to say the DPF should be replaced instead of giving it a chance with cleaning. The guys at the workshop said that I should give it a try with cleaning since it's a really cheap option ( 100£ manwork and 80£ cleaning, in Romania)  and only then should I consider replacing it if it doesn't do the trick. But I'm getting decent mileage between regens now in my opinion ( about 50-80 mg soot per km average, depending on the driving style )

14 hours ago, BogdanB said:

Yes, the oil ash value has been reset. 

And honestly, I think it's a total scam and waste of materials to say the DPF should be replaced instead of giving it a chance with cleaning.

Agree. I would try this first, for sure.