Only 3 years after its last cleaning my diesel particulate filter showed a service warning again (after running fine for 10 years before the previous cleaning). I set up an appointment with my mechanic and between then and the time I had the appointment also the check engine light had popped up. This has happened a few times in the past few years only for it to disappear again within a couple of hours. I attributed those to a fluke. However this time it coincided with my appointment and I had the mechanic check it out.
He told me the particulate filter is more than 50% filled up with soot/ash which is why the service warning showed up. The check engine light mentioned issues with the glow plugs and the throttle plate no longer properly responding.
I was thinking if there could be a link between the issue of the throttle plate and the surprisingly fast built up particulate filter. My train of thought was that the throttle plate (which according to my research in diesel engines still regulates airflow to the engine) malfunctioning would mean that it can no longer properly regulate the airflow to match the injected diesel creating less than ideal fuel/air ratios during combustion.
I usually work with small diesel engines with manual control of the fuel pump and no throttle plate and there sudden changes in the amount of fuel causes the engine to smoke excessively until the air/fuel mixture has stabilized again a couple of seconds later. I was wondering if this malfunctioning plate could have caused similar conditions with excessive soot in the exhaust clogging up the filter beyond its capacity for self cleaning.
My mechanic - whom I know quite well and trust completely - said he would not categorally say no but it seems very unlikely, only potentially in combination with the broken glow plugs.
Is there any possibility my train of thought could still be correct or is this indeed extremely unlikely? Id love to have someone else think about it.
I have a 2010 Mitsubishi Outlander 2.2 DI-D.