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When To Replace Your Car's Water Pump


4 Symptoms Of A Bad Water Pump And The Cost To Replace It

The cooling system in your car helps maintain the engine temperature in an optimal state whether it is cold or hot outside. But to run optimally the engine needs a constant and steady supply of antifreeze which is provided by the water pump. So a failing water pump can bring up many issues in the vehicle and show warning signs that every driver must be aware of to minimize damage to the engine. This guide will walk you through what to expect when your water pump fails and why you must replace it. 

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How Does The Water Pump Work?

The water pump is essentially a centrifugal pump. As the water enters through the inlet, it is shot over the pump impellers that rotate along with the engine and push the coolant through the outlet which is connected to the engine block. The impellers are connected to a shaft that is attached to a pulley. This pulley is operated by the engine through the crankshaft and is often run by the timing belt or in some cars, an auxiliary drive belt or the serpentine belt

The water pump is a necessary component of the entire cooling system and is responsible for maintaining consistent coolant flow throughout the system. The coolant entering the pump is directed into the engine block and cylinder head. It then flows through the radiator where the antifreeze cools down and is fed back into the water pump for repumping into the engine block. This cycle repeats itself to ensure the engine remains at operating temperature. If the water pump fails, the coolant circulation is stopped which results in engine overheating. If the engine continues to overheat for a prolonged period, engine seizure can occur, which is absolutely the worst thing for an engine. Let us now take a look at the signs of a failing water pump to prevent such a catastrophe. 

What Happens When The Water Pump Fails?

The symptoms of water pump failure are not very peculiar but can certainly give you a starting point as to what’s causing the issues in your car. Here are the signs of a bad water pump:


Overheating Engine

If you notice the engine coolant temperature is very high and the engine is running erratically then stop the car immediately to avoid any damages. If the coolant flow is obstructed, the temperature within the engine increases drastically. This can cause the valves and pistons to seize up or the cylinder head to crack. These effects are catastrophic for the engine so it is necessary to inspect and replace the water pump immediately. Overheating can also be caused by a clogged radiator, faulty thermostat, leaking radiator hoses, failing radiator fans, etc. Always inspect the entire system before replacing any component. 


Leaking Coolant

The water pump contains several seals and gaskets that ensure the coolant is contained in the engine block and circulated efficiently throughout the system. With prolonged use, these gaskets and seals are prone to failure due to wear and tear causing drying, cracks and complete deterioration. This allows the coolant to escape from the system and is visible as leaking fluid from the engine block. Depending on the colour of coolant in your engine, if you see red, green or orange residue on the ground and around the engine then it is an indication of a water pump gasket or seal failure

Leaking fluid can also cause a gradual buildup of minerals on the surface of the pump. This can further cause rust and pitting of the pump surface and noticeable holes and cavities. The rust and corrosion build-up can cause coolant contamination which can affect other cooling system components as well. 


Steam Coming From The Engine

Steam emanating from the engine bay is the most obvious sign of engine overheating and can indicate a serious cooling issue with the vehicle. If the engine continues to run at unsafe temperatures, the coolant in the systems starts to evaporate as the engine temperature is higher than the antifreeze’s boiling point. This is evident from steam blowing from the radiator cap. If you notice this then it is strongly advised to stop the vehicle immediately and have the engine inspected. 


Noises From The Water Pump

A broken water pump and pulley assembly can cause unusual sounds from the engine bay where the water pump is located. A high pitched whining sound can mean the belt driving the pulley is too loose which in turn can be caused by a bad pulley bearing or failing belt tensioner. A broken pulley bearing can also cause a grinding sound to come from the pulley. Since the pulley and water pump are a single unit, any issue with the pulley or bearing requires a complete pump replacement. 


Once you ascertain that the issue lies with the water pump then having it fixed should be a priority as driving with a broken water pump is likely to cause serious engine problems. Replacing the water pump can be a challenging task and if your water pump is part of the timing belt then the replacement can become even more difficult. Whenever you replace the water pump, make sure to also swap out the timing belt as leaking coolant can deteriorate the belt material and reusing it can cause further issues with the new water pump. 

It is advised to have the water pump and timing belt replaced by a professional unless you have considerable experience with mechanical fixes. Also once the water pump is replaced it is necessary to flush the entire cooling system to remove all the contaminants stuck in the engine block or radiator.

How Much Does It Cost To Replace A Water Pump?

Accessing the water pump can be hard because most water pumps are part of the timing belt assembly and hence are situated behind the timing belt cover. Therefore considerable disassembly is required to access the water pump and one also needs to properly fit the timing belt once removed. At this time, it is recommended to also replace other components such as the timing belt, tensioners, pulleys and water pump gasket as well as replacing these components when they fail may cost extra labour charges. Apart from disassembly, the cooling system also needs to be drained and replenished. 

This is what makes water pump replacement expensive on most vehicles. The cost of water pump replacement will vary between different vehicle makes and models and greatly depends on how much disassembly is required and how many components are replaced. All these factors are why water pump replacement can cost you anywhere from $400 to $1400. This includes part and labour charges. One way to save some serious cash is to purchase from PartsAvatar to benefit from discounts on all related parts. This can help you circumvent some of the cost of water pump replacement. 

FAQs

Q) What Causes Water Pump Failure?

Here are the reasons for water pump failure:

  • Contaminated coolant can have abrasive and harmful particles that can destroy the seals on the water pump. Also using coolant type that is not recommended by the manufacturer can cause issues.
  • Seals and gaskets are often the most vulnerable parts of the pump. With prolonged use over hundreds of kilometres, the gaskets and seals wear out, dry up and break leading to water pump leakage.
  • An overly tight belt can cause excess stress on the pulley shaft and bearing leading to bearing failure or seal damage.


Q) How Long Does A Water Pump Last?

Water pumps are constantly at work as the engine is started and so they endure a lot of wear and tear. But water pumps are designed to last a long time by the manufacturers and you can expect about 100,000 to 150,000 km of service life before you start noticing the symptoms of water pump failure. This estimate varies from vehicle to vehicle and also on the quality of the pump installed. Low-quality pumps generally show signs of failure within 60,000 km. Always replace your water pump along with the driving belt at the recommended replacement interval to ensure prolonged service life from all components. 


Q) What Components Should Be Replaced Along With The Water Pump?

If the water pump in your car is driven by the timing belt, then having it replaced at the same time is crucial and also because both these components have similar service life spans. It is also recommended to replace the idler pulley and belt tensioner to ensure the new pump works efficiently and lasts longer. A timing belt kit usually includes all necessary components that must be replaced with the belt. (idler pulley, belt tensioner, hardware, gaskets and water pump). The coolant must also be replaced and even flushed especially if the colour of the coolant is drastically darker from fresh coolant colour. 


Q) Is It Okay To Only Replace Water Pump Seal Or Gasket If The Pump Is Leaking Instead Of The Entire Pump?

The water pump seal is part of the shaft assembly and if it fails then the only way to fix the problem is to replace the entire pump unit. On the other hand, the gasket can be replaced individually but it is still advised to replace the pump as the replacement process is complicated and often expensive when done by a mechanic. So having the pump replaced will future proof the system and also prove to be more economic in the long run.