Mercedes GLK Overheating Problem

I understand you are experiencing engine overheating issues with your Mercedes GLK I encountered a similar problem with my previous vehicle, a 2014 Opel Insignia The symptoms were quite alike, including the check engine light and the overheating Was the engine temperature consistently high, or did it fluctuate Also, did you observe any unusual noises coming from the engine compartment before the problem became apparent

The temperature seems to fluctuate, creeping up especially when I'm stuck in traffic No strange noises, just the overheating and the check engine light What was the issue with your Opel's engine cooling, and how did you resolve it

In my case, it turned out to be a faulty coolant temperature sensor which was providing incorrect data to the ECU, resulting in the radiator fan not operating as required While your initial suspicion of a defective speed sensor may be accurate, it could be worthwhile to have the coolant temperature sensor checked as well Given the complexity of modern engine cooling systems, I would recommend consulting a qualified mechanic for a proper diagnosis Continuing to drive the vehicle with the engine overheating could lead to severe engine damage

I took it to my local shop, and you were spot on – the speed sensor on the radiator fan was indeed the culprit They replaced the whole fan assembly, and the overheating is gone Cost me about 250€ all in I appreciate your help in pointing me in the right direction