From the workshop
In on a lack of power, out with the fault found and fixed. Elliot reads the scanner, shows the blocked filter and explains what actually caused it.
59 seconds, with captions. Full transcript below.
this car we had in was a Mercedes A200 diesel. The customer reported lack of power.
We’d run some diagnostics on it, and as you can see from the report, that the DPF filter was reading 400% full due to a component fault, which is pretty excessive.
We removed the DPF, we could see it was completely blocked. And the temperature sensor wasn’t working.
So the customer opted for a secondhand DPF filter, which we had cleaned for him professionally, fitted a new lambda, um, exhaust temp sensor, cleared all the faults, set everything back to zero, road tested it, and the car’s perfect.
The, uh, the road test was pretty unbelievable, the difference it made from when it come in. So yeah, happy customer.
Elliot says “we removed the DPF” in the clip, and he means he took it off the car to inspect it — which is how he could see it was blocked solid. A replacement filter went back on. Deleting a DPF is illegal, an automatic MOT failure and an MOT fraud risk for whoever sold you the car afterwards. We do not do it, and nobody offering it is doing you a favour.
DPF problems get blamed on short journeys almost automatically, and owners get told to go and thrash it up a motorway. That was not the issue here. The exhaust temperature sensor that governs the burn-off had failed, so the filter never regenerated properly no matter how the car was driven. Diagnostics is what tells those two situations apart, and guessing wrong costs you a filter.
A new DPF for one of these is not cheap. The alternative here was a used filter, professionally cleaned, which is a legitimate repair and considerably less money. We priced both and the customer chose. The road test afterwards was, in Elliot’s words, unbelievable against how it arrived.
The diagnostics page explains what you actually get for the fee, why a code reader on its own is not a diagnosis, and what happens if we cannot find the fault.
How our diagnostics work, and what they costEvery one filmed in the Dudley workshop, with the mechanic who did the work explaining it.
See all workshop videosGet the fault found before anyone starts replacing parts on a guess. Send us the registration and the symptom, and we will tell you what testing it properly involves.