How to Tell if my Water Pump is Bad

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A loose accessory belt will cause a whining noise that increases with acceleration. The fix for this could be as simple as tightening the belt, replacing the belt, or replacing the belt tensioner. If you hear a grinding or growling noise from the front of the engine, however, that indicates a bad bearing. There are other bearings on the front of the engine that can fail, but in any case you should immediately take it to a mechanic to confirm and repair the problem.

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2. Testing a Bad Water Pump

When testing for a bad water pump becomes difficult, you can divide your diagnostic into three simple procedures that give you a better chance of revealing the fault and the type of failure you are facing.

The advantage with this approach is that your diagnostic can make it easier to tell whether other components played a role in your water pump failure, which you must correct before installing a new pump.

So first, we'll check the operation of your water pump, followed by a diagnostic of the bearing, and signs of a potential water pump seal failure. You can combine one or more of these methods until you can verify the failure and possibly pinpoint the cause.

Diagnosing Water Pump Operation

The purpose of this type of diagnostic is to check whether your water pump is working.

  1. Place your transmission in Park (automatic) or Neutral (manual) and apply the parking brakes.
  2. Remove the radiator cap and start the engine.
  3. Let your engine idle for about 15 to 20 minutes to let it reach operating temperature.
  4. At operating temperature, you should see through the radiator opening how the coolant begins to circulate; otherwise, either your thermostat has failed to open, the radiator is clogged, or your water pump isn't working.
  5. If you suspect the water pump isn't working, replace the radiator cap and, using a shop rag to prevent burning your hand, squeeze the upper radiator hose (the one going from the radiator to the engine).
  6. With a working water pump, you should feel the surge of coolant as you release the radiator hose.
  7. When you don't feel the surge of coolant, squeeze the upper radiator hose again, and while an assistant depresses the accelerator to increase engine speed, release the radiator hose.
  8. If you still don't feel the surge of coolant through the upper radiator hose, most likely coolant is not circulating. Get inside the passenger compartment.
  9. With the engine still idling, turn on the heater to Max.
  10. If you feel very little heat or no heat coming out, and you've noticed your engine overheating, you'll need to locate the fault among a stuck-closed thermostat, a clogged radiator, and a failed water pump. Go on to the next procedure.

A sutck closed thermostat will block coolant circulation and overheat the engine, as well.

Photo courtesy Hoikka1 on Wikipedia

Diagnosing Water Pump Bearing Failure

One way to check for worn out or failed pump bearing is to check for water pump shaft movement.

1. With a faulty bearing, you can often hear a squealing, howling, or sometimes a grinding noise coming from the front of the engine. Even if you don't hear any noises, apply the next steps.

  • To isolate the source of the noise, you can use a large screwdriver or a length of rubber hose to isolate the source.
  • Start your engine. Keep your hands and screwdriver or hose away from moving parts.
  • Touch the front of your water pump housing with the tip of the screwdriver shaft or one end of the hose.
  • Put the other end of the screwdriver or hose against your ear. If the bearings are worn out or damaged, you'll clearly hear the noise coming from your water pump as the bearing causes a rough rotation of the pump shaft.

Be aware that a loose or slipping drive belt, an AC compressor, alternator, steering pump, belt tensioner, or another accessory driven by the belt may also cause a squealing noise.

2. Check the water pump shaft and pulley for signs of damage or movement.

On vehicle models where a serpentine, drive or timing belt runs the water pump, you may need to remove the belt to manually check the water pump pulley.

  • Wiggle your pump pulley with your hand. If you notice damage or movement, replace the water pump.
  • Rotate the pulley by hand. It should turn freely but not feel loose or rough; otherwise, replace the pump.
  • On vehicles where the radiator fan attaches to the water pump assembly, you can grab the fan and carefully wiggle the fan. If you notice movement, most likely the water pump will need replacing, but check that all mounting bolts are tight. And carefully examine the fan as well. With enough time, a loose or damaged fan will cause the water pump to fail.

Diagnosing Water Pump Seal Failure

A bad seal will cause the water pump to fail, allowing coolant to leak. Often, a simple visual inspection of the water pump itself can reveal the leak of a seal or even a gasket.

  1. On some vehicle models, you have easy access to the pump for inspection. On other models, you may need to remove an engine front cover to gain access and even raise the vehicle and supporting it on jack stands.
  2. Once you gain access to your pump, use a flashlight to inspect the pump. Check the pump weep or relief port (at the bottom, to one side, or under the pulley), around the shaft or pulley and mounting area (where the pump comes in contact with the engine block)
  3. Also, look where the radiator hose attaches to the water pump.
  4. Look for traces of coolant residue or tracks of dried coolant. If your water pump is driven by a drive or serpentine belt and you find traces of coolant, make sure the leak is not coming from an over-head hose or another source above the water pump.

A slightly wet weep hole isn't cause for concern. However, a dripping weep hole means a failed shaft seal.

If your timing belt runs the water pump, it's a good idea to replace the belt at the same time.

Photo courtesy of Petar Milošević on Wikipedia

Final Thoughts

You should begin diagnosing a water pump failure as soon as you suspect something is wrong. Apply the three methods outlined in this simple guide. An early diagnostic can save you thousands of dollars in repairs. Remember that driving a car with a failed water pump can leave you stranded in the middle of the road, with an overheated engine and a much more expensive repair.

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.


It’s important to remember that coolant reaches scalding temperatures and is under a lot of pressure while the vehicle is running and for a few hours after it’s shut off. Never remove the radiator cap or touch any part of the cooling system until the engine has cooled completely.

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Coolant Leaks

Coolant leaks from the water pump are common and a clear sign that it’s time to replace the pump. The coolant is stored inside the water pump using a series of gaskets and seals. Once these parts wear out, loosen, or crack, you’ll end up with radiator fluid leaking out of the front of your car toward the center. Coolant is usually green, orange, or red. Orange coolant could have rust in it.

Water Pump Replacement Cost

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Cost for replacement of the water pump vary greatl

Cost for replacement of the water pump vary greatly depending on the size, make, and age of the car, though you can expect to pay anywhere from $310 to $730 total. Expect to pay more at a dealership or with certain types of vehicles.

Parts alone (water pump and additional parts) will run about $70 to $400. For labor, expect to pay about $240 to $330 (using a typical $80-$110/hr. rate). On average, water pump replacement is a 3 hour job.

You may pay less if you buy the pump yourself and give it to the mechanic to install, though use caution and make sure to buy the parts from a reputable source. Make and model of vehicle can have a significant effect on total cost. Fees and taxes may increase these figures depending on your location. 

Though water pump replacement can be expensive, engine replacement is much worse. The vehicle should not be driven until needed repairs are done.

If you’re not sure when your water pump was last replaced, doing it soon is cheap insurance for your engine. Most people like to tackle the water pump with the timing belt while they’re in there.

How to Tell if Your Water Pump Is Bad?

While you are checking car transport open vs enclosed> to see which way works better for you, it would be good to know how to tell if a water pump is pumping, to avoid adding repair or replacement cost on top of your car bill of lading. Ensuring that your car works properly before shipping a car cross-country is equally important whether you choose open carrier auto transport or enclosed auto transport. Your car will give you signs that there’s something wrong with the it, all you need to do is learn to read them.

Symptoms of a bad water pump

You should note that water pumps, just like other engine components, wear out over time. Few factors can cause your water pump to fail. So, what causes a water pump to go bad? A water pump can go bad due to;

Bad/wrong coolant. It means that using incompatible or contaminated coolant can create corrosion in the water pump.

improperly installed/worn out belt. A misaligned belt or too tightened belt can cause the water pump to stop functioning optimally.

Low Coolant. A water pump running low or dry due to leaks will lose the lubricate needed to keep the seals in working order. If the seals overheat, it’ll go bad and cause more leaks.

Anytime you notice any of the following symptoms,

Anytime you notice any of the following symptoms, you have to inspect your water pump quickly.

Coolant leak at the front of your car: The water pump is manufactured to function with gaskets and seals to ensure a steady and adequate flow of coolant travels from the radiator to the engine block. So, if these seals and gaskets shrink, crack, wear out, or break entirely, there will be a coolant leak from underneath the water pump.  If you notice a leak of coolant that is red, orange, green, or pink in color, ensure you where the leak comes from or contact a professional mechanic to do a thorough diagnosis. Most often than not, it is a dripping coolant that you should replace before it causes severe engine problems?

Loosen or Noisy water pump pulley: if you start noticing a high-pitched sound in front of your car from time to time, you might have a loosen belt that generates a harmonic whining or buzzing sound as it turns. The loose belt can result from a loosened water pump pulley or a worn-out bearing that operates the water pump. When the bearing inside the pump starts wearing out or goes bad entirely, it has to be replaced.

If you notice a buzzing or whining sound in front of your car while idling or driving, ensure you inspect your water pump or contact a professional mechanic for a proper diagnosis.

Overheating Engine: If the water pump goes bad entirely, it will lose the power to transport coolant through the engine block and the head cylinder. This can cause overheating, and if not given timely attention, it will cause catastrophic engine damage like engine knocking, burnt pistons, burnt head gasket, or cracked cylinder head.

If you find that the temperature gauge on the dashboard is rising, it’s surely that something is wrong with your cooling system, which is likely to be antifreeze leaking or a faulty water pump. You want to inspect your cooling system or contact a professional mechanic for thorough checks.

Deposit builds, Rust, and corrosion of the water pump: Over time, there will be a buildup of different minerals in the water pump due to gradual leaks. Inspect the water pump surface, you may notice rust a non-compatible coolant mixture, contaminated coolant, or radiator cap leak. Pouring the wrong coolant in your car will the normal process of the engine coolant. In addition to these symptoms, there may be small holes due to cavitation or corrosion.

If you notice these symptoms, you should follow the steps below and replace your water pump or contact a professional mechanic for proper diagnosis and fixes.

Steam coming from the front of your engine: Finally, if steam is coming from the front of your car while idling or driving, it tells your engine is very high in temperature which can also translate to an engine overheating. As explained above, it must reach its normal operating temperature quickly and maintain this constant flow for an engine to run efficiently.

If you notice steam under your hood while driving, you should stop your car at a safe place and inspect where the steam is coming from or contact a professional mechanic. It is a bad idea to drive an Overheating engine.

How to fix water pump leak

Fixing or replacing a water pump leak may be very difficult on some cars while on other cars, it can be a relatively easy job. If your engine runs on a timing belt, the water pump will likely be belt-driven, so replacing the water pump will require losing many components, including the timing belt. If this implies on your car, you have to contact a professional mechanic to replace your water pump. Kindly note that this guide will only be helpful if replacing your water pump does not require removing your timing belt.

This guide’s whole point is to show that you can replace the water at home and save hundreds of dollars. You are not going to do anything crazy. You don’t have to jack the car up. This is an effortless job, and you are using some standard tools.

Tools Needed:

  • A wrench
  • A Ratchet
  • Socket sets
  • Thread locker
  • Flathead screwdriver
  • Plastic gasket scraper

Other things Needed:

  • Water pump
  • Water pump gasket
  • Coolant
  • Drain pan
  • No-spill funnel

Now, you must use the correct coolant. Otherwise, you will damage your engine. Grab your vehicle owner’s manual and check for the specific coolant that your car uses. You can also check the coolant label, and its uses to show the cars that the coolant can be used on.

Step 1: Park your Car: Park your car on a strong, level floor, and engage the hand brakes.

Step 2: Allow the car to cool: you want to make sure that your car is cool. When systems are always pressurized when the vehicle is hot, you don’t want the hot coolant to come out and shoot at you when you remove the water pump.

Step 3: Remove the battery terminal cables: To get access to the water pump and perform a safety job, you have to remove the battery terminal cables.

Step 4: Remove the water pump belt: you need to remove the water pump belt because it wraps around the water pump pulley. Grab your spanner and get it on the drive belt tensioner and pull down to release the tension on the belt so you can easily get the belt out of the pulley.

Step 5: Drain your entire cooling system: place your drain pan under your radiator and remove the outlet hose and your radiator to drain out and flush your coolant.

Step 6: Unbolt the water pump bolts: you have to remove the bolts holding your water pump by breaking it free with your wrench. water pump bolts could be in different sizes, so you have to remove the bolts and place on the same holes on the new water pump. You have to do this one at a time in order to track where comes from. This will make installing the new water pump a lot easier.  Make you don’t see coolants coming from the thread holes. Because if you see coolants you have to add some thread locker on the bolts while reinstalling them.

Step 7: Pop off the water pump: After losing the bolts, you have to pop off the water pump.

Step 8: Clean the mounting Surface: Before you go on with mounting the new water pump, you have to clean the old gasket and sealant debris on the mounting surface.  To do this, you should grab your plastic gasket scraper and scrape off the old gasket debris. I do not recommend using a metal gasket scrapper, it can scratch the surface and cause a leak. If you’re having a hard time removing the gasket debris, applying a little bit of brake cleaner will help remove it easily.

Grab your smooth sandpaper and do a final cleaning on the mounting Surface so that when you mount the new water pump, you won’t have any leaks from the surface. Now, grab your clean rag and clean the surface and inside the water pump housing If any debris fell inside, you won’t want that to circulate to the engine.

Step 9: Mount the gasket on the water pump. Grab two water pump longer bolts and fix them on the water pump, place your gasket on it and apply a little gasket maker. You want to make sure that you’re using a gasket marker that is compatible with coolant, else the gasket is going to wear off and you’ll have a coolant leak.

Step 10: Mount the water pump.  Apply water thread locker on the bolts before mounting the water pump.

Step 11: Tighten the water pump bolts. You can now go ahead hand-tighten the first two bolts to hold the gasket and water pump in place. Hand-tighten the other bolts and get them ready for torquing down. It is important that you torque them down in a Crips-cross pattern.

Step 12: Reinstall the drive belt. Now is a pretty time to replace your drive belt if it is old or has some cracks on it. You have to fix back the drive belt just the same way you removed it. You want to make sure that the belt is centered on the pulleys and not misaligned.

Step 13: Fix back the battery terminal. You have to fix back the battery terminal and torque them down.

Step 14: Refill your coolant. Remove your coolant reservoir cap and refill it. You want to make sure there is coolant on your engine before starting it, if not, you will run your water pump dry and damage it.  You can use a spill-proof funnel to refill the coolant.  This will help remove any air trapped in the system. For a visual presentation on how to do this, watch this video.

What does a bad water pump sound like? Often, the problems that happen with the water pump result from worn-out bearing inside the water pump pulley and not the pulley itself. When the bearing starts going bad, it causes a grinding, whining, or buzzing sound in front of your car.

Q: When should I replace the water pump?

Water pumps should last the life of a timing belt. The water pump can last up to 70,000 – 90,0000 miles. If your water pump has covered 70,000 – 90,000 miles, it is ideal for replacing it when doing extensive work that requires taking off the timing belt.

Q: Should you replace the thermostat when replacing the water pump?

The thermostat may have encountered a lot of issues due to the bad water pump. So, the thermostat should be replaced when replacing the water pump, especially if the thermostat has not been replaced for a very long time.

Q: Can a leaking water pump cause rough idle?

Can a bad water pump cause rough idle? Yes. Due to the effects of a bad or damaged water pump like engine Overheating and leaking coolant, your engine will experience rough idle.

Q: How expensive is it to replace the water pump?

The cost of replacing a water pump depends on your car make, model, year, and how difficult it will take to replace your water pump. On average, you can spend around $250 to $700. The water pump’s actual cost should be $50 – $100 while the service fee should be around $200 – $600.

Q: How do I know if my water pump is working?

Your water pump might be working fine if you do not notice any of the following signs of a bad water pump;

  • Coolant leak at the front of your car.
  • Steaming coming under your hood.
  • Engine Overheating.
  • Loosen or Noisy water pump pulley.

Water pump FAQs

Can you drive a car with a bad water pump? No, it’s not recommended to drive your car at all if the water pump is bad. If your car’s water pump is failing, it’s important to get it fixed as soon as possible. A bad water pump can cause your engine to overheat, which can lead to serious damage to your engine. Will a new water pump improve performance? A new water pump won’t improve your engine’s performance, but it can improve cooling performance and keep your engine cooler. However, it depends on the cooling performance of the old water pump. If the old pump was working properly, a new pump is unlikely to improve performance. How long can I drive with a bad water pump? How long you can drive with a bad water pump depends on how bad the water pump is. In fact, we do not recommend driving your car at all if your water pump is bad. A faulty water pump can lead to an overheated engine, which can result in very expensive repair costs. What does a water pump sound like when it’s going out? Most of the time, a bad water pump will not make any noise at all. But sometimes a water pump that goes out can make a lot of strange noises. These sounds can include loud grinding or clicking sounds, humming or whining sounds, or even low moaning sounds from your engine.