Commercial vehicle manufacturer MAN Truck & Bus has called customers of certain trucks and buses with Euro 6c engines, types D2676LF51-53 or D2676LOH35-37, to have their vehicles checked at a MAN specialist workshop. Engine variants of the later Euro 6d and Euro 6e emissions standards are not affected by this service requirement.
In very rare cases and under adverse circumstances, some engines built between 11/2016 and 08/2019, can suffer damage and subsequent fires. In the vehicle types mentioned lead-free bearings, due to new regulatory requirements, were used. Cases of damage can occur in particular where there is excessive aging and contamination of the engine oil, resulting in damaged oil filter components – for example, due to non-compliance with maintenance intervals or improperly carried out maintenance work.
Other known reasons for such damage are: special operating conditions and in particular overspeeding of the vehicle, penetration of (cooling) water into the engine oil, engine tuning, use of non-approved engine oils and their mixing, and, the use of service parts such as engine oil filters, air and diesel filters, that do not meet the manufacturer’s specifications.
The legally required lead-free bearings, of the mentioned years, are more sensitive to contamination and oil aging. If maintenance appointments and scheduled workshop actions are not adhered to, the first cases of damage can occur in vehicles between 400,000 and 500,000 kilometers. If all planned service and oil changes for these engine types are adhered to and on time, MAN does not see any noticeable accumulation of engine damage, but rather a very high level of robustness across all engine series with mileages of well over a million kilometers in some cases. Compliance with prescribed service intervals is therefore of the utmost importance for the reliability and safety of the vehicles. MAN has informed affected customers of this in a letter. MAN has informed the affected vehicle owners several times since the end of 2022 asking them to take appropriate workshop measures to prevent damage and increase robustness.
Following the information provided to customers, a total of over 60,000 measures have been carried out in MAN-approved workshops. This corresponds to around 50% of the affected vehicles. For the other vehicles in the field, workshops were informed and specifically instructed regarding the relevance of oil quality.
In addition, appropriate technical measures have been implemented, such as the precautionary replacement of an oil filter cover that may have been damaged by outdated oil. Where this is required, due to particularly demanding usage profiles, an application-specific adjustment of the oil change intervals and other measures were initiated in direct communication with the customers.
MAN has a fleet of around 880,000 vehicles on the road in Europe. Of these, around 120,000 trucks and over 5,000 buses built between 2016 and 2019 are equipped with the engine types mentioned. Measures have already been carried out on numerous vehicles in recent years. According to MAN’s findings, there have been 170 fire cases in the general population since the engines mentioned were launched on the market, which – among other possible causes – could be attributed to the engine damage pattern mentioned. In 2024, 18 cases occurred, the cause of which most likely lies in the damage pattern described.
All fires resulted in property damage but there were no serious personal injuries. As a preventative measure, MAN is now once again calling on those vehicle owners who have not yet taken advantage of the service offer in recent years.
Basically, fires have different causes and can also be due to completely different factors. They must therefore be examined individually. When monitoring products, MAN pays a lot of attention to engine damage, which in rare cases can also lead to fires. If the worst comes to the worst, an analysis is carried out using the expertise of experts and in close communication with the customer.
SOURCE: MAN Truck & Bus
