Why is my C-Class temperature gauge rising quickly after starting the engine?

Home > Gari Forums > Mercedes Benz Forums > Mercedes Benz C Class Forums > Mercedes Benz C Class Overheating Engine Forums

Post a New Topic

Why is my C-Class temperature gauge rising quickly after starting the engine?

If your engine temperature rises rapidly after startup, it could be due to a stuck thermostat. The thermostat regulates coolant flow between the engine and radiator. In Pakistan, hard water o r low-quality coolant can lead to mineral deposits that jam the thermostat, preventing coolant from circulating. This causes the engine to heat up very quickly, potentially leading to overheating within minutes of driving.

Talha Kyanii asked on 10 Oct 2025 18:11:40 pm

2 Answers

13 views |

Gari Master - on 10 Oct 2025 18:12:29 pm

This is a classic sign of a stuck o r failed thermostat. The thermostat controls when coolant flows to the radiator. If it gets stuck in the closed position—often due to mineral deposits from hard water o r old coolant—it prevents coolant from circulating, causing the engine to heat up rapidly, even within the first few minutes. Replacing the thermostat and flushing the cooling system usually solves the problem.

Gari Master - on 10 Oct 2025 18:12:43 pm

This is often caused by a faulty radiator fan o r its related components relay, fuse, o r temperature sensor. In Pakistans hot climate, especially during traffic jams o r long trips, your car depends heavily on the radiator fan to keep the engine cool when airflow is minimal. If the fan isn’t turning on when needed, the coolant temperature rises quickly, leading to engine overheating. A mechanic should check whether the fan is working properly and whether the cooling system is getting proper power and signals.