Mercedes-Benz CLK350 fan belt issue indicating low coolant despite adding coolant on Mercedes-Benz CLK350

Submitted by Vehicle Owner · Jun 23, 2025
Published by RepairPal

Problem overview

Some Mercedes-Benz CLK350 owners report experiencing fan belt issues and low coolant level warnings even after adding coolant. These alerts may be triggered by an unresolved low coolant level in the system, which requires checking when the engine is cold to prevent engine damage. Additionally, some owners find that airlocks in the heater radiator can disrupt the coolant system's function, leading to warning messages. Inaccurate readings from a faulty coolant sensor may also cause warnings despite adequate coolant levels. Furthermore, problems with the coolant pressure cap or leaks in the system can contribute to these low coolant alerts. If the cooling fan and AC are not functioning properly alongside the coolant warnings, it is advisable for owners to inspect the sensor, wiring, and the entire cooling system for faults. It is recommended to consult a qualified mechanic for accurate diagnosis and prompt resolution to avoid further engine damage.

2 people reported this problem
1 comment
Schedule Repair

Mercedes-Benz CLK350 vehicles with this problem

Average mileage: 68,000 miles
(68,000 - 68,000)

Search for another problem

RepairPal Car Genius

Ask our experts about your Mercedes-Benz.

RepairPal Car Genius™ is a free resource for vehicle owners seeking advice on maintenance, auto repair, shop inquiries, estimates, and finding a trustworthy repair shop in your area.

 Auto Repair Expert Auto Repair Expert

Call us at 877-913-1554

Available 9am – 6pm ET Monday through Friday

Call Our Experts