Mercedes-Benz 300SD Car is running hotter than normal Inspection at your home or office.

Common reasons for this to happen:

• Low Coolant: With any engine temperature related issue, the first thing to check is the level of the coolant. If it’s low, then the system doesn’t have enough fluid to do its job correctly. Low fluid can be caused by many things, including not properly topping it off after draining the old coolant, and leaks from various parts, such as one of the radiator hoses, the water pump gasket, a damaged or open bleeder valve and more.

• Sticking Thermostat: This could be a sign that your thermostat is about to fail. If it has started sticking, but hasn’t quite given up the ghost, it’s possible to see higher engine operating temperatures without overheating.

• Damaged Radiator Cap: Most modern radiator caps are pressure caps. They’re designed to increase the boiling point of coolant by pressurizing the system. If your cap is failing (the seal is generally the problem), then you can expect to see higher than usual engine temperatures.

• Deteriorating Hose: Your radiator hoses are responsible for transporting coolant to and from the radiator. Over time, they age and deteriorate. If a hose has gone “soft”, it’s possible that is has partially collapse and created a bottleneck that limits coolant flow, which will increase the temperature.

• Faulty Temperature Sensor: It’s possible that the temperature sensor on the engine block is faulty, and sending inaccurate information to the car’s computer/dash gauge. In this instance, the reading is incorrect and your car’s engine temperature is most likely normal.