Should I really worry about DPFs?
I have been worried by your frequent references to costly problems relating to diesel car particulate filters.
We have a 2 year old Subaru Legacy with the 2.0 diesel engine. I have asked our garage about the filter problems and they say that there is a warning yellow light (in exhaust pipe shape) which appears when the filter is not working optimally.
Apparently people sometimes ignore this light and thus the problems develop. The garage suggests that when the light appears one should run the car constantly at about 50 mph, at over 2500 revs, until the light goes out and the filter is working properly again. I have not had a warning light, so they think there is unlikely to be a problem with our system of usage of the car.
Does this mean we should be OK in the future, even at much higher mileage?
If so, this could reassure other diesel car drivers and give them a way to avoid problems developing.
We have a 2 year old Subaru Legacy with the 2.0 diesel engine. I have asked our garage about the filter problems and they say that there is a warning yellow light (in exhaust pipe shape) which appears when the filter is not working optimally.
Apparently people sometimes ignore this light and thus the problems develop. The garage suggests that when the light appears one should run the car constantly at about 50 mph, at over 2500 revs, until the light goes out and the filter is working properly again. I have not had a warning light, so they think there is unlikely to be a problem with our system of usage of the car.
Does this mean we should be OK in the future, even at much higher mileage?
If so, this could reassure other diesel car drivers and give them a way to avoid problems developing.
Asked on 13 March 2012 by J W, Darlington
Answered by
Honest John
Good advice from the garage. Road speed is irrelevant to actively regenerating a DMF. All that is important is constant engine speed above 2,000rpm. Subaru had trouble with this engine in the first Legacy, but sorted it out for the Impreza and Forester with 6 speed box, then for the most recent incarnation of the Legacy and Outback.
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