Water / Coolant Pumps

Porsche Water / Coolant Pumps

The water pump also known as coolant pump is the heart of the engine’s cooling system.
It’s job is to regulate the flow rate of the engine coolant.

Build:

1. Housing - The housing is the outer shell that encases the water pump. It is typically made of cast iron or aluminum

2. HUB or PULLEY - Attached to the top of the shaft is the hub or pulley. It’s run by the drive belt.

3. BEARING - The bearing assembly, which rotates with the shaft,

4. SHAFT - The water pump shaft rides against the bearing with the impeller connected on the bottom and a hub or pulley connected to the top

5. IMPELLER - The impeller is located inside the housing and is connected to the bottom of the shaft. It may be metal or plastic. The impeller spins and distributes coolant throughout the cooling system at a rate determined by the engine RPMs.

6. MOUNTING GASKET - The mounting gasket seals the water pump to the engine

Coolant is typically drawn into the water pump from the engine block and directed into the radiator. There it passes through thin tubes that are designed to provide as much surface area as possible to cool the hot liquid. The liquid then travels back into the engine cylinder head and block where it can pull additional heat out of the engine. The water pump continues this process the entire time the engine is running. Typical pump can move about 10,000ltrs of liquid per hour when engine is idling and at high speeds upto 35,000ltr! That would be a size of a small outdoor pool.

With a failing water pump, your car can be severely damaged by overheating. Your car's water pump cannot last forever. A water pump should last anywhere between 60,000 and 100,000 miles.  If it fails, it is significant to replace it as soon as possible to prevent much more damage to your vehicle.

Most water pump failures are caused by an external issue, and not the pump itself. When replacing a water pump, it is important to investigate the cause of its failure.  Below are 3 top causes of water pump failure caused by external issues and techniques for prevention. 

#1 Contaminated Coolant

Engine coolant protects a vehicle’s engine from extreme heat and freezing temperatures. Quality coolant and water are critical to water pump operation. Contaminated oil is the leading cause for original and replacement water pump failures. Hard water, mixing coolants and system debris are all contributors to coolant contamination. 

Water quality varies greatly and hard water can result in mineral deposits lingering in a cooling system. These mineral deposits can restrict flow and damage seals. Remember to use distilled water when mixing coolant. 

While the wide range coolant colours is largely attributed to dye, chemistry can vary greatly between different products. Combining multiple coolants is not recommended. Use a 50/50 mixture of the recommended coolant and distilled water when replacing. 

To remove lingering debris, completely flush the engine, heater core and reservoir prior to installing a new water pump. Remember to discard old coolant fluids and debris in accordance with local laws.  

#2 Too Much Sealant

Over applying sealant to water pump gaskets is the second leading cause for water pump failures. Excess sealant can be squeezed into the water pump chamber, restrict flow or damage seals. 

Remember: sealant should only be used with fiber gaskets. Sealant is not necessary for rubber gaskets. 

#3 Defective System Components

Bent or cracked fan blades, a defective fan clutch or idler pulley bearings can put stress on the water pump bearing. These additional vibrations on the engine can reduce the life of a water pump’s bearings.