Tag Archives: egr fault

Mercedes-Benz A200d Carbon Build Up In Engine.

This Mercedes A200d with the 2.1 diesel engine came into us for a Diagnostic Code Read because its EML (Engine Management Light) was on.

The Codes were –

  • P0401 Exhaust gas recirculation (EGR) system – insufficient flow detected
  • P0638 Throttle actuator control (TAC), bank 1 – range/performance problem
  • P200A Intake manifold air control actuator, bank 1 – performance problem

After checking some of the live data we decided to remove the EGR pipe to have a look inside the intake system, the system was full of carbon build up which was causing blockages.

After speaking to the customer we found that he only uses the car for short journeys and it very rarely gets a long run.

We are seeing this as a weekly occurrence at the moment, modern diesel engines are not designed for lots of short journeys they are more designed for long distance commuting.

When a modern diesel engine is driven on a long journey it carries out a DPF (Diesel Particulate Filter) regeneration which basically means it cleans out the exhaust system of carbon and soot build up, the same carbon and soot is found in the engine and long journeys help to clean that too.

Once we had cleaned out the intake and EGR system we cleared all stored engine codes and took the Mercedes for a long road test, upon return we carried out another Diagnostic code read and none of the codes had returned and all live data was reading correctly.

The car was given back to its owner and we also advised him to go on at least one long drive per week or the car would be back to us with the same fault.

Aarons Autos car service garage.

Your friendly car garage in Derby

Give us a call at Aarons Autos for more info.

EGR blocked on this Renault Traffic.

This Renault Traffic came into us with its EML (engine management light) on and had a lack of power.

The first job was to carry out a diagnostic code read which showed up several codes relating to EGR valve faults.

As it is quite a big job we needed to get authorisation from the customer to remove the front end off his van access the EGR valve.

Once we had removed the front end we could access the EGR valve and start to remove it, once removed we could see the problem.

Completely blocked EGR valve.

The EGR valve and pipes were completely full and blocked with carbon deposits which was stopping the valve from working properly.

Blocked EGR pipes.

We replaced the EGR valve and cleaned out all the pipes to and from the valve, this cleared the codes and allowed the vehicle to drive at full power.

New EGR fitted.

Unfortunately due to the amount of carbon build up in the pipes we determined that the rest of the intake system would have similar carbon deposits in them and may need cleaning in the future.

We advised the customer to take the van on several long journeys at an average RPM of 2500 this will allow the engine to carry out a regeneration of the DPF (diesel particulate filter) and help clean out carbon deposits from the intake system.

This will no doubt have to be carried out several times to get the engine into a good internal condition.

The biggest problem with modern diesels is that people drive them economically and on short journeys, this is what causes the carbon deposits to build up and cause issues, ideally they should be used for long journeys at least once a week to allow the engine to clean itself.

For more info on EGR or DPF faults don’t hesitate to contact us.

Aarons Autos car service garage.

Your friendly car garage in Derby

Give us a call at Aarons Autos for more info.