Providing cooling air in an efficient way reduces fuel consumption and lowers the impact on the environment. With the products from our traditional Visco® brand, which has been around for more than 50 years, MAHLE offers a range of highly proven and powerful fans and fan drives. The Visco® fan drives generate additional savings and reduce engine noise. In commercial vehicle engines and powerful passenger car engines, they enable on-demand control of the cooling air flows by creating a frictional connection to the fan wheel—depending on the temperature—and influencing its speed. If no cooling air is needed, the fan drive switches off completely.

A failure can make itself noticeable as follows:

• Engine overheating
• Grinding noises coming from the viscous coupling

Causes for a defect could be:

• Transport damage (oil leak)
• Visco clutch deformed due to an accident

An A/C compressor is indispensable for temperature management in a passenger car: It compresses the gaseous refrigerant, heating it up in the process. The refrigerant passes via the intermediate stops of the A/C condenser and the evaporator, where the required evaporation cooling for the cabin is produced, and it is then returned to the A/C compressor—and the cycle starts all over again. The unit is generally driven by the engine via a V-ribbed belt. For lubrication, the A/C compressor is filled with a special oil, some of which circulates through the air conditioning system with the refrigerant. The size of the A/C compressor varies according to the size of the system. With the acquisition of the thermal management activities from Delphi Automotive PLC and the resulting integration of the new air conditioning compressor product group into the MAHLE Group, MAHLE has further expanded its leading position as an original equipment manufacturer. MAHLE is also the competent technology-partner for all leading OE-manufacturers when it comes to vehicle cooling and climate control. MAHLE Aftermarket’s range of high-quality A/C compressors is extensive and includes the latest generation of electrically driven, vehicle-specific units.

A failure can make itself noticeable as follows:

• Noises
• Inadequate cooling performance

Causes for a defect could be:

• Low oil level
• Bearing damage
• Leaks
• Moisture

The A/C condenser is the counterpart to the A/C compressor: The latter compresses and heats the refrigerant, while the condenser reduces the temperature again. To this end, the gas flows through the pipework and fins of the A/C condenser installed upstream of the coolant cooler, thereby emitting heat. This lowers the pressure and causes the refrigerant to liquefy. To facilitate logistics and assembly, MAHLE’s range not only includes numerous A/C condensers but also finished modules. These are ready-made units comprising a flat-tube condenser and the collection/expansion tank with integrated drier.

A failure can make itself noticeable as follows:

• Insufficient cooling capacity
• Air conditioning condenser fan running continuously
• Complete failure of the air conditioning system

Causes for a defect could be:

• Leaks (rock chips, accidents)
• Contamination of the cooling fins
• Blockages (damage to the air conditioning compressor)

If the coolant temperature rises, it expands. This causes the pressure in the cooling tower to rise at the same time. To keep this pressure constant, MAHLE’s robust expansion tanks receive the expanding coolant via a valve located in the cap. In this way, they reliably ensure that the pressure is returned to the predefined level and the load on the cooling tower reduced.

A failure can make itself noticeable as follows:

• Coolant loss (leakage) from various system components or the expansion tank itself
• Excessively high coolant or engine temperature
• Cracked or burst expansion tank or other system components

Causes for a defect could be:

• Excessive pressure in the cooling system due to a faulty valve in the cap
• Blockages (corrosion, sealant)
• Material fatigue

With technologically advanced oil coolers from MAHLE, not only are oil change intervals longer, but, thanks to the almost constant temperature spectrum of the engine oil, the engine’s service life is also increased. To fulfill all of our customers’ demands, we offer a wide selection of air- and coolant-cooled oil cooler types. The variable stacked-plate oil cooler features a particularly lightweight, space-saving, all-aluminum design with no coolant housing.

A failure can make itself noticeable as follows:

• The oil is getting too hot
• Engine oil and coolant have mixed

Causes for a defect could be:

• Oil cooler is dirty on the outside
• Cooling fins are corroded
• Oil cooler is leaking (cavitation) due to the use of sealing compound during installation

Coolant radiators are installed in the air flow of the vehicle frontend. They have the task of dissipating heat produced by combustion in the engine and absorbed by the coolant.

A failure can make itself noticeable as follows:

• Poor cooling performance
• Increased engine temperature
• Permanent radiator fan operation
• Poor air conditioning system performance

Causes for a defect could be:

• Loss of coolant caused by damage to the radiator (gravel throw, accident)
• Loss of coolant through corrosion or leaky connections
• Poor heat exchange caused by external or internal impurities (dirt, insects, limescale deposits)
• Soiled or old coolant

As a global partner, MAHLE develops and produces thermal management systems and components for well-known automobile and engine manufacturers.

MAHLE thermostats work just as well in tropical heat as in arctic cold. They quickly bring each engine to the correct operating temperature by controlling the cooling circuit. MAHLE provides a variety of thermostats and other temperature-regulating components for various requirements.

A failure can make itself noticeable as follows:

• Engine overheats
• Engine does not reach its operating temperature
• Heater does not warm up
• Loss of coolant

Causes for a defect could be:

• Incorrect antifreeze used (corrosion on the thermostat)
• Cooling system not flushed/cleaned during repair (foreign object jammed the thermostat valve)