[Superdaws]

Hi Everyone,

Trying to diagnose this issue with my M57. 120,000km. Particle filter warning came on iDrive so looked into it further.

Had the 480A and 481A codes as well as Pressure sensor codes. I took it for a 1:30-2hr drive at 100kph about 2500-3000 rpm to try clean it out and tried to force a DPF regen in ISTA a few times. The active regen never happened.

Im beginning to think it may not be a clogged filter? Ive run the EGR test and results posted, do you think the pressure sensor could be bad? The figures are not "way out there" but it didnt measure atmosphereic pressure exactly with engine off.

Coolant temp was at 80C+ and EGT at at least 350C when i was trying to force a regen. Having read more into the target temps for the M57 on this forum too, im starting to think it may not be reaching target temp of 88C+ either so ill look at replacing the main and EGR thermos, but i doubt that would cause the pressure results im seeing?

Filter, sensor, thermos? Any ideas, thanks in advance.

[335dlci]

What's 80+? Even 8 degrees off can cause issues. Your dpf is clogged. Forcing a regen doesnt always work.

[Superdaws]

Originally Posted by 335dlci

What's 80+? Even 8 degrees off can cause issues. Your dpf is clogged. Forcing a regen doesnt always work.

Thanks for your response. I can't be totally specific on the temp based on the info from my drive as the hidden temp gauge kept dropping off screen while I was driving sand it wasn't really safe to switch it while driving. So the only time was when I pulled over to try and re-force regen again, I'd pull the temp again and have a look.

That said highest I saw was 81, and I didn't shut the engine off, so I'll look that replacing the thermostats.

[Yozh]

Your regens should still be happening above 75C. If you have a failed thermostat, chances are you are getting below 70-75C on the highway.

[jdub486]

A bad MAF sensor was causing my car to not re-gen recently.

[Superdaws]

Thanks everyone for your input. Main and EGR thermostats were changed and then i was able to force a regen, DPF cleared! Yozh i think was right, it must have been dropping below 75C on the highway. I managed to get the temp indicator to stay up permanently and its now sitting comfortably 87-89C.

Cheers.