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Robert, BMW Technician
Category: BMW
Satisfied Customers: 4708
Experience:  Fully qualified 19+yrs exp/self employed technician in the UK
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I have a 1 series bmw after i drive for about 20 minutes a

Customer Question

I have a 1 series bmw after i drive for about 20 minutes a warning light comes on for a couple of minutes, the symbol looks like an exhaust , half with dots and half without
Submitted: 3 years ago.
Category: BMW
Expert:  Robert replied 3 years ago.



Hopefully i can help..


The mentioned warning light will be particulate filter or DPF as its known - could be blocking up..this can happen alot with cars seldom used or only used for very short periods of time where they the car itself/ecu doesnt get time the self regenerate the dpf to burn off the captured soot inside..if it reaches a point of blocking or the filter is becoming full then it will bring on that warning light..All cars with DPF's must be driven at prolonged speed preferably once a week or at the very least in some cases once a fortnight for around 10 miles in 4th gear at 70mph on a clear motorway. This helps raise the temperature in the exhaust to start the regeneration process. If that doesnt work - Using suitable diagnostic equipment, a 'forced' regeneration can be done the diagnostic tool in a program to raise the temperature while the car is stationary engine running.engine oil & oil filter needs replaced before and after.You can also now buy additives that you put in your tank to help keep the DPF clean so maybe something to try for example "Cataclean"..if the end result still doesnt help..then a new DPF will likely be fitted or if you can find a good second hand one..Removal of the complete DPF unit for the exhaust will be an MOT failure so wont be an option..But as above maybe try the motorway method and see if that helps if not then you know which step to take next..I do hope this helps