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DPF problems
DPF light on? Let's find out why it's blocking.
A diesel particulate filter catches soot. When it blocks, the car loses power. We find out why, so it doesn't keep happening.
What a DPF does
The DPF sits in the exhaust of diesel cars and vans and traps soot. It cleans itself by burning the soot off on longer drives, which is called a regeneration. Lots of short trips, a faulty sensor or another engine fault can stop that happening, and the filter fills up.
Signs to look out for
- DPF warning light on
- Car down on power or in limp mode
- Fan keeps running after you switch off
- Higher fuel use than normal
- Smoke from the exhaust
Book a check soon. You can usually drive gently, but leaving it can turn a simple fix into a new filter, which costs far more.
What usually causes it
- Short journeysThe filter never gets hot enough to clean itself.
- Pressure sensor faultsThe car thinks the filter is blocked when it isn't, or the other way round.
- Other engine faultsInjector, EGR or boost problems that create extra soot.
- Failed regenerationsThe cleaning cycle keeps getting interrupted.
Find the cause first
How we fix it
- Check the DPF dataSoot level, back pressure, temperatures and regeneration history.
- Find the root causeSensors, pipes, glow plugs, EGR or driving pattern.
- Fix and regenerateRepair the cause, then run a forced regeneration where it's needed.
Your options
Recommended
Book us
Bring it to our HQ at Mallory Park. You get a price before any work starts.
Book a check →Fix it yourself?
Best left to us
A DPF fault needs live data and testing to find the cause, so it's best we see the car.
Common questions
Do you remove DPFs?
No. Removing a DPF is illegal on UK roads and the car fails its MOT. We find out why it blocked and fix it properly.
Will a forced regeneration fix it?
Sometimes. But if something caused the blockage, it will block again. That's why we find the cause first.
Do I need a new DPF?
Usually not. Most DPF problems are a sensor, another engine fault or the driving pattern. We'll tell you before anything is replaced.
Where are you based?
Unit 3, Mallory Park Circuit, Leicester LE9 7QE. An easy drive from Leicester, Coventry and Nottingham.