Mercedes-Benz C300 4MATIC AC Compressor Replacement Cost

Know what price you should pay to get your vehicle fixed.

AC Compressor Replacement
The average cost for a Mercedes-Benz C300 4MATIC AC compressor replacement is between $921 and $1446. Labor costs are estimated between $202 and $256 while parts are priced between $719 and $1190. Estimate does not include taxes and fees.

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AC Compressor Replacement

What is an AC compressor?

The air conditioning compressor is the heart of the air conditioning system. It moves refrigerant through the system, and compresses low pressure refrigerant to create high pressure refrigerant.

How does the AC compressor work?

The serpentine belt or drive belt at the front of the engine drives the A/C compressor, thus allowing the compressor to pump refrigerant through the system. Some vehicles use a compressor with a clutch that engages the compressor electronically when the A/C button is turned on, and some vehicle's compressors turn any time the engine is running. The high pressure created is necessary for the air conditioning system to function and without it the air conditioner would blow just warmer than ambient temperature inside the vehicle. The compressor also uses check valves that allow refrigerant to flow in one direction.

What are the symptoms related to a bad AC compressor?

The compressor is necessary for the air conditioner to operate, and when it fails, the most common symptom is warm air from the vents. Since the compressor places additional load on the engine, engine speed (RPM) will drop slightly if the A/C button is turned on, but if the compressor is not functioning properly, the engine idle speed may not drop. This may indicate that the compressor clutch is not functioning, or internal compressor failure has occurred. When the check valves fail, the high and low pressure sides of the refrigerant system may being to equalize in pressure, and the air conditioner may blow warmer air. Finally, a squealing or grinding noise may be heard from the compressor in the event of mechanical failure.

Can I drive with an AC compressor problem?

In most situations a vehicle with a faulty air conditioning compressor is perfectly safe to drive. However, if grinding is heard from the compressor pulley, bearing failure may occur, causing the serpentine or drive belt to work its way off the pulley, and other necessary belt driven components. If this occurs, the battery warning light will illuminate, and the engine will stall due to lack of electrical power.

How often do AC compressors need to be replaced?

Failure of the air conditioning compressor is common because moisture or clogs in the air conditioning system will place high stress on the compressor. Compressor clutch failure is much more common on older vehicles, but some modern compressors still utilize an A/C compressor clutch to turn the compressor on and off. In general, A/C compressors tend to fail after 60,000-70,000 miles, but that time may be lengthened depending on use, demand, and operating conditions.

How are AC compressor issues diagnosed?

Diagnosis of the air conditioning compressor requires advanced knowledge of air conditioning systems, and a good understanding of the relationship between temperature and pressure of a liquid and gas. A technician with proper training, and certification is required to repair an air conditioning system. Professional grade equipment is used to read high and low side pressure, and the technician must rely on hours of classroom and hands-on training to understand the readings and diagnose the faulty part. If the compressor is suspected to be faulty, the technician will ensure proper compressor clutch operation prior to diagnosing the compressor as the culprit.

AC Compressor Replacement Cost Estimates

The average cost for an AC Compressor Replacement is between $921 and $1446 but can vary from car to car.

How is an AC compressor replaced?

Replacement of most air conditioning components requires complete evacuation of the air conditioning system with refrigerant recovery machinery. Once all ozone depleting refrigerant is out of the system, the serpentine belt, refrigerant lines, and electrical connectors must be removed. Finally, the mounting bolts and hardware must be removed to allow the compressor to separate from the engine. Once those components are re-installed, the technician will remove all air from the system in preparation for recharging the system with new refrigerant.

RepairPal Recommendations for AC compressor issues

Refrigerant is environmentally harmful, and should never be released into the air. Instead, a proper refrigerant recovery machine must be used to protect the technician and the environment. We do not recommend attempting to recharge the A/C system, as off the shelf products available to consumers tend to contain substances that can cause damage to expensive refrigerant recovery equipment. Lastly, if your vehicle has not been converted from R12 to R134a refrigerant, the best time to have this service completed is when the air conditioning system is already being serviced.

What to look out for when dealing with AC compressor issues

Refrigerant is a dangerous chemical that can cause injury if improperly handled, and discharging into the atmosphere will cause damage to the ozone. Refrigerant types are updated over time, and the appropriate type must be used. If there has been an update or conversion from an older refrigerant type, a label should be placed under the hood to make your technician aware of the change.

Can I replace the AC compressor myself?

The air conditioning system is not serviceable without proper recovery and evacuation equipment, and attempting to release refrigerant into the air can result in severe chemical burns. Repair of A/C components should be left to certified professionals, and is not considered a DIY job.