DPF Problems and Repairs in Wymondham
Forced regeneration tried firstIf your diesel's DPF light is on or it's gone into limp mode, the filter is usually clogged with soot. We find out why, try a forced regeneration first, and only replace the filter if it can't be saved.
- Specialist cleaning, crack-tested first
- Genuine DPF and sensors if it needs replacing
How much soot burns off
For illustration purposes only
What a DPF does
How it works
A diesel particulate filter sits in the exhaust and traps the soot a diesel engine produces, so it doesn't come out of the tailpipe. Every so often the filter needs to burn that soot off. This is called regeneration.
Regeneration needs heat, which comes from driving at a steady speed for a while. Cars that mostly do short, slow trips never get hot enough, so the soot keeps building until the DPF light comes on.
The car also has to be in good health to regenerate. Most need more than a quarter of a tank of fuel, and another fault, such as an engine warning light, the wrong oil level or a failing turbo, can stop a regeneration from running at all.
Signs your DPF is blocked
Recognise the signs
A blocked DPF usually warns you before it gets serious. If you spot either of these, it's worth getting it looked at.
DPF warning light
Usually amber, and often the first sign.
Limp mode
The car cuts power to protect the engine, and won't go above low revs.
Not sure what you're seeing? Some cars give earlier signs, such as running differently, but these vary from car to car. Your handbook may list the ones to look for on yours.
How we deal with a blocked DPF
Our process
We start by finding out why it blocked, because clearing the filter without fixing the cause means it’ll block again.
1. Find the cause
We ask how the car is used, because lots of short journeys is the most common reason. If that doesn't explain it, we scan for fault codes and look for anything stopping it regenerating.
2. Forced regeneration
Using our diagnostic equipment, we make the car run a regeneration in the workshop to burn the soot off.
3. Professional clean
If it keeps blocking, we remove the filter and send it to a specialist. It's tested for cracks first, then cleaned.
4. Replace if needed
If the filter can't be cleaned, or we can see it's too far gone, we replace it with a genuine DPF and genuine sensors.
We don't do DPF deletes
We'll take a DPF off to have it cleaned or replaced, but we never remove one for good. Deleting or tampering with a DPF is illegal, and a car without its filter fails its MOT. Some firms still offer "DPF delete" services. We don't, and we'd rather fix the filter properly.
DPF questions
Can I keep driving with the DPF light on?
Try a steady drive of about 20 minutes with the revs around 2,500 to 3,000 and more than a quarter of a tank of fuel. That’s often enough to clear an amber light. If it stays on, or the car goes into limp mode, book it in. Check your handbook too, as some manufacturers give their own advice.
How much does DPF work cost?
It depends on what the filter needs, so we give you an estimate once we’ve seen the car. If it needs replacing, the estimate includes genuine sensors, so there are no surprises.
Do you use DPF cleaning additives?
No. If a forced regeneration doesn’t clear it, we remove the filter and have it professionally cleaned.
How can I stop my DPF blocking again?
Give the car a steady 20-minute run regularly, keep more than a quarter of a tank of fuel in it, and don’t ignore the light. Getting other faults fixed promptly helps too, since they can stop the filter regenerating.
Do petrol cars have a DPF?
Many newer petrol cars have a similar filter, called a GPF. We can scan one for fault codes, but for now GPF repairs usually need to go to the main dealer.
DPF light on?
Call us or book online. We'll find out why it's blocked and give you an estimate before any work starts.