Mercedes-Benz GLK DPF cleaning: checking pressure after refitting

01 / NHC MOTORS

Check the vehicle before cleaning the filter

The concern behind DPF cleaning is often whether it will clog again. Removing deposits and investigating why they accumulated both matter when trying to avoid repeated work.

We carried out a smoke test on this GLK before removing the DPF. Smoke is introduced into the pipework to look for leakage. The vehicle-side inspection accompanied the filter work.

02 / NHC MOTORS

Dry and wet cleaning with the DPF removed

The removed DPF was connected to the equipment for dry and wet cleaning. The photo below shows discharge from the filter during cleaning.

A change in wash-water colour is not enough to decide that the car is ready. We kept the before-and-after bench readings and also checked the filter after refitting.

03 / NHC MOTORS

Bench peaks of 18 and 10 hPa; 0.01 bar after refitting

The equipment recorded a peak of 18 hPa before cleaning and 10 hPa afterwards. Both original displays are shown below.

After refitting, the diagnostic tool displayed differential pressure of 0.01 bar at a coolant temperature of 74°C. This reading is retained for later comparison alongside the operating conditions.

Peak values on the bench display for the removed filter. These are separate from in-vehicle differential-pressure readings.

04 / NHC MOTORS

Continue monitoring after the clean

Cleaning was completed and subsequent monitoring was agreed. If a concern returns, the saved readings can help focus the next inspection.

Repeated DPF warnings or reduced power call for a review of recent repairs and driving conditions as well as the filter. This helps establish an inspection sequence before paying for another clean.

Further action will be considered while monitoring symptoms and diagnostic results after cleaning.

Frequently asked questions