[NorcyUK]

Hi,

I own an N57 325d and have recently started getting the particulate filter warning on iDrive. There is no change to how the car drives, but does give the warning after every start up within a few miles of setting off.

I’ve had the it scanned and nothing indicates that the DPF is blocked. Could this just be a faulty pressure differential sensor? Or am I likely looking down the route of a replacement/re-engineered DPF?

[Rich_D]

Are there any fault codes? Not just DPF related.

Have you checked when it last did a regen and what the ash mass, soot mass and backpressure values are?

Also is the coolant getting up to temp, as thermostats are a known weak point, they make the engine run cool and can prevent a regen, it's an 88C thermostat.

Something like ISTA, Bimmertool, Bimmerlink, Carly, etc can check all this.

[Silver Streek]

What is the fault code? If you have a fault code that's causing the dash warning for the dpf, likely in amber colour if its the first warning your DPF will not regenerate. The fault code prevents the ECU starting a regen cycle. As mentioned above you need to check that basics such as coolant temp must be above 75degs, you must have over 1/4 tank of diesel. Also as Rich's mentions above if the Ash mass is too hight this will also prevent a regen.

I've had this with mine, turns out it was because I was running the fuel below 1/4 tank when I wasn't using the car as much so the dpf stopped regenerating and sooted up. As soon as I figured out what it was it's never happened again. As soon as it hits 1/4 tank I refuel again.