DPF on a C250CDI

[SmartMAC]

I do mainly very short start stop trips and the car rarely gets up to temperature which is not ideal for the DPF to regenerate.

I have noticed in two occasions that after a long periods of start stop short trips there is a bit of judder when driving on a high gear at low speeds. This disappears when I do a long run at normal speeds.

Is this a typical behaviour of a DPF on a modern car? When it did it first, I took it to Mercedes but they could find nothing wrong with it.

 

[euler]

I do mainly very short start stop trips and the car rarely gets up to temperature which is not ideal for the DPF to regenerate.

I have noticed in two occasions that after a long periods of start stop short trips there is a bit of judder when driving on a high gear at low speeds. This disappears when I do a long run at normal speeds.

Is this a typical behaviour of a DPF on a modern car? When it did it first, I took it to Mercedes but they could find nothing wrong with it.

It's a typical behaviour for a 250cdi... at least a stock vehicle... In my 250 cdi remapped the frequency of regeneration of DPF reduced a lot... What's the reason? The remap increased the boost pressure, so in the fraction air/fuel, there is more air, and consequently it takes a lot more to DPF saturates! I discussed this issue in other forum. I don't understand why Mercedes programmed the engine in this way. Notice that even when the DPF is not regenerating, the engine doesn't work in a fluid way. It has a response delay and some annoying turbo lag. With a simple remap all those symptoms tend to disappear! As i understand the trick is to increase the boost pressure. You can do it with a remap or with a multichannel tuningbox that connects to the boost sensor...

 

[SmartMAC]

Thanks for that. I thought it might have something to do with it. Reading about DPF on the net makes me wonder if I should have gone for a petrol car.