Mercedes-Benz Sprinter 3500 Temperature gauge is maxed out Inspection at your home or office.

Common reasons for this to happen:

• Low Coolant: The first suspected cause of your temperature gauge maxing out is low coolant. If this occurs, your engine can overheat, and serious damage can result, up to and including cracking the block. However, if the engine isn’t actually hot (the temp gauge is maxed out but there’s no abnormal levels of heat from the engine), this isn’t the problem.

• Broken Temp Gauge: If the temperature gauge is maxed out but the engine isn’t actually hot, then the problem may be a broken temperature gauge. The needle may be stuck in the hot range (this can happen after overheating the engine), or a stepper gear in the gauge may be damaged.

• Failed Temp Sensor: If the temperature sensor on your engine block has failed, it may not send any information to the system, or it may send an erroneous signal, causing the gauge to rise without any actual overheating. It’s also possible that the sensor is shorting.

• Failed Thermostat: If your car’s thermostat sticks in the closed position, coolant will not fully cycle through the engine, and it will begin to overheat. Your temperature gauge will rise quickly, particularly if it is very warm outside.

• Cooling Fan Motor Failure: If the motor for your radiator cooling fan fails, it will not cycle on. This reduces the amount of airflow over the radiator, meaning that much of the heat is retained by the coolant, and it will not be able to absorb more from the engine.

• Bad Fan Switch: Another reason your radiator fan might not be working is a bad fan switch. This switch controls the cycling of your radiator fan(s), and if it fails, it can cause overheating.

• Air in System after Coolant Service: If you’ve recently had your engine coolant drained and refilled, it’s possible there’s air in the system. Air bubbles can form and block coolant from cycling through the engine, causing it to overheat.