The temperature in the engine from the dismantled cooler was before cleaning 95°C. This temperature was lowered with 13°C down to 82°C after cleaning. The temperature in the engine, where the whole cooling system was cleaned, was lowered from 100°C to 90°C, a decrease with 10°C. As an alternative to change the cooler due to high temperatures in the engine (dirty engines), the cooling system can easily be cleaned and the lifetime of the engine cooler can be increased immensely.