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Deflection / Guide Pulley, timing belt
How do you know if your water pump isn’t working?
Indirect symptoms of a broken pump are unusually high engine temperature and a strong smell of coolant in the passenger compartment. When the bearing starts wearing out, you might hear humming, screeching or squealing sounds from under the bonnet. Later, elements of the unit start rattling. Extraneous noises can also occur when the impeller is askew.
If you notice any of these symptoms, inspect the pump visually. A leak from its mounting seat or housing indicates a malfunction. Also, check the bearing. For this, wiggle the drive pulley of the pump. There should not be any free play.
A defective or malfunctioning pump isn’t able to create the required pressure in the cooling system. This can lead to engine overheating. If the unit loses tightness, coolant starts leaking out. Coolant deficiency can also cause engine overheating. You shouldn’t continue driving if the coolant level in your car is critically low. Destruction of the pump bearing may cause the drive belt to wear prematurely or even snap.
If the pump is driven by the alternator belt (serpentine belt), the battery won’t charge when it snaps, and some other units, such as hydraulic power steering and air conditioner, will cease functioning. If the cooling system pump is driven by the timing belt or chain, though, their breakage will lead to far worse consequences. For instance, there is a risk of damaging the valves, piston breakage, failure of the camshaft and its bearings, deformation or cracking of the cylinder head.
Can you drive a car without a water pump?
No, you can’t. The water pump is a crucial component of the cooling system, and its breakdown leads to overheating and severe engine damage. Moreover, constructionally a car can not operate without a water pump: its pulley is a key element of the valvetrain or auxiliary equipment drive. It is impossible to ensure proper tensioning of the drive belts without this part.
Do you need to replace the water pump together with the timing belt?
Yes. The water pump, timing belt, and pulleys are always replaced together. These car parts have roughly the same life expectancy. And even the smallest defects on them are unacceptable, as the engine’s working condition directly depends on the valvetrain.
What causes a car water pump to fail?
Using poor-quality coolant or failing to replace it on time may cause the seals to wear prematurely, making the unit leaky. To avoid seal damage, don’t let the pump work without coolant even for a short time. Leaks from the shaft seal wash out the lubricant from shaft bearings, causing their fast breakdown. In addition, the bearings may fail when the pulleys are misaligned or the drive belt is overtightened. The pump’s drive shaft may get damaged for the same reasons.
Moreover, impurities, dirt and various additives (radiator stop leak, for instance) contained in the coolant, promote the wear of contacting parts, form deposits on the impeller, and become the cause of corrosion.
How long does it take to change a timing belt and water pump?
Installing new parts can take 3–10 hours and sometimes even more. The difficulty of the procedure depends on vehicle design, the number of auxiliary units, and layout of the engine bay.
In some cases, it is recommended to replace the thermostat when installing a new water pump. Many motorists wonder whether it is reasonable or not.
Generally, unlike the belt and pulleys, installing a new thermostat during replacement of the water pump is not necessary. Moreover, its service life is about 1.5 times longer than that of the pump. However, for some engines of Volkswagen, Vauxhall and Opel cars replacing the thermostat is advisable. They have the thermostat mounted directly behind the timing belt drive system. So, to gain access to this part, the entire timing belt system will have to be removed. Moreover, these parts cannot be reused, thus, they are to be replaced even if they are not faulty. That is why replacement of the thermostat in such cases is a reasonable solution.
Do you have to drain the coolant to replace the water pump?
Usually, a large amount of coolant drains out when you detach the hose from the pump. That is why it’s better to drain the coolant into a container beforehand, to avoid spattering the engine bay and spilling toxic substances. Make sure the container is clean if you plan to reuse the coolant.
Can a bad water pump cause rough idle?
No, as unstable engine idling is caused by other malfunctions and is not related to defects of a water pump.