Although their share is declining, there are currently still around 14.1 million registered passenger cars with diesel engines in Germany. That is around 28.8 percent of the entire nationwide car fleet. However, it is precisely these cars that have to overcome a special, costly hurdle during the main inspection (HU) by TÜV, Dekra and other approved testing organizations.
Diesel drivers face costly repairs after general inspection
The MOT is a legally required inspection of the road safety and environmental compatibility of motor vehicles in this country. Different guidelines apply – depending on whether it is a new or a used vehicle. The former must be presented to TÜV, Dekra and Co. three years after their initial registration. Used cars are inspected every two years after the first MOT.
What’s special is that diesel vehicles often fail the first inspection, especially when it comes to Ford models with 1.5 and 2.0 liter Ecoblue engines, as the ADAC reports. Even as new cars, these often fail the technical and environmental requirements that come with a general inspection.
“Upon closer inspection, it is usually apparent that the particle filter is no longer doing its job and therefore has to be replaced at great expense,” explains the ADAC. And this can be more expensive than many probably suspect. Because: “Depending on the measures required, the cost of the repair can be up to 3,000 euros. […].”
Diesel particulate filters (DPF) are prone to blockages, especially if the vehicle is mainly driven on short journeys. A blocked or non-functioning exhaust gas purification system leads to increased pollutant emissions and can lead to failure in the MOT.
Numerous problems
The background is that diesel vehicles have to comply with strict emission limits in order to minimize environmental pollution. In addition to the particle filter, the exhaust gas recirculation valve (EGR) is therefore also tested. This can become coked by the soot contained in the exhaust gas, meaning that it no longer opens and closes properly, thus worsening the emission values. A defective EGR also leads to a negative rating.
But other things can also cause problems for diesel vehicles during the general inspection. These include the following:
Wear of components
Diesel engines operate under higher pressure and are therefore more susceptible to wear of certain components:
- turbocharger : Defects in the turbocharger, such as leaks or damage to the blades, can affect engine performance and emissions.
- Injection system : Problems with the injectors can lead to incomplete combustion and increased pollutant emissions.
Technical defects
In addition to the exhaust emissions, general technical aspects are also checked:
- Brakes : Worn or unevenly worn brake pads and discs can pose a safety risk.
- Chassis and steering : Defective shock absorbers, springs or steering systems can affect driving stability.
Software problems
In the past, there have been cases where software updates have been used to manipulate emissions. Vehicles that have not received such updates or whose updates are faulty cannot comply with emissions limits.
Sources: Statista, ADAC
This article was created with machine assistance (AI) and carefully reviewed by the editors before publication.
By Dana Neumann
