DTC related to engine overheating

Doposud provedeno bez úspěchu

The engine overheating warning is displayed - switch off the engine. This warning appears after longer journeys, especially with higher demands on the engine, e.g. after approx. 60-70 km on the motorway. According to the on-board indicators, the coolant is not overheating, the coolant temperature indicator is at 90°C, and there are no fluctuations in the coolant temperature. The time for the water to reach warm-up temperature is within the accepted limits. The oil temperature when the message activates is usually around 115°C. The temperature rises progressively while driving. At the point when the engine load is reduced, e.g. stopping and leaving the engine idling, the oil temperature drops again. It looks like oil cooling is taking place, just not to a sufficient degree. By monitoring the coolant and engine oil levels, everything is within the limit long-term, and there is no leakage. The fluid looks visually normal.

The authorised workshop in Liberec selected a trial-and-error strategy for replacing individual parts. Based on the diagnostics in the authorised dealership, the fuel pump control unit was replaced first, then the water pump, timing system and finally the coolant temperature sensor. As the next step, the authorised dealer recommended replacing the thermostat, which, given the description of the behaviour of the coolant and oil temperatures, is an unlikely cause and just another unnecessary repair cost.

I am contacting you because I rather seriously question the professional competence of the technicians, even though this is an authorised dealership.