Car Water Pump Problems? 6 Most-Common Issues & Fixes

The water pump is a major part of your car’s cooling system. The radiator may transfer heat out, but the pump is the reason the coolant stays flowing through the whole system.

The pump can last for years but will eventually need to be replaced. When that time comes, you will have signs that the pump needs to be replaced.

We’ll cover the most common issues that occur, and how each can be remedied.

Can you drive your car with a bad water pump? Check out this article to find out!

#1 – You Have Coolant Under Your Car

This is one of the more obvious issues that you can identify without opening the hood or hearing the car running.

Coolant on the ground is a definite indication that the water pump may be leaking from the impeller shaft seal, the connection to the engine, or where the radiator hoses attach to the pump housing.

The impeller shaft has a seal that prevents coolant from leaking on the underside of the water pump. When that seal wears out, it drips coolant down the engine and onto the ground.

car water pump

How to Fix It

When you find the water pump is leaking, you need to determine where the leak is to know how to attempt to fix it.

Hoses may drip if the hose clamp isn’t supplying enough camping pressure to contain the coolant. It may need to be tightened with a screwdriver if it is a worm-style clamp. If it is a spring-style clamp, it may need its position adjusted to provide the proper clamping force in the right location.

If the body of the water pump is leaking where it attaches to the engine block, it may need to be resealed with a sealant or properly tightened with the attaching fasteners. Some replacements require the gasket providing the seal to use sealant, while others don’t. It may be that one was used and missed a step.

If the impeller shaft seal is weeping coolant from the body of the water pump, that seal needs to be replaced. Most of the time it’s cheaper to just replace the water pump as a complete unit.

But in the rare case that a unit is not available, you may need to source a rebuild kit for the water if that does exist. A qualified mechanic can replace the water pump as a unit or rebuild your original and then complete the replacement process.

#2 – Your Car Is Running Hotter Than Normal

You may notice that your car starts running hotter than normal or what you would expect from the driving conditions. It can fluctuate when sitting in stop-and-go traffic, but you don’t expect it to run significantly hotter all the time.

If you see your temperature gauge indicating a higher temperature, your water pump may be on the way out.

How to Fix It

Running at a higher temperature in heavy traffic or pulling a heavy load is normal. You’re pushing the cooling system a little harder than normal, and it should keep your car running cool.

Before you assume your higher temperature is because of the water pump failing, check the amount of coolant in your cooling system. You can open the radiator if it is cool, but if it’s hot, you will want to give it time to cool off. Never open a hot radiator.

  • If the coolant is low, you can refill it to the full level. You can also run the engine and watch if the coolant is circulating.
  • If the coolant is moving, that indicates the water pump is turning correctly and moving the coolant through the engine and cooling system.
  • If the coolant is stagnant, the water pump has a problem and should be rebuilt or replaced.

Never continue to drive your car if it is overheating. A faulty water pump can overheat the engine and cause significant damage to the cylinder heads, the cooling system, and the radiator.

#3 – The Water Pump Is Making A Grinding Sound

The engine will make a little sound when it runs, but you shouldn’t hear a grinding sound. If your water pump is making a grinding sound, the bearings on the impeller shaft have gone bad.

These bearings can fail because of contamination or a leaking seal allowing coolant to soak the bearings. Coolant touching the bearings can cause corrosion, and eventually bearing failure.

How to Fix It

Bearings may come as part of a rebuild kit for your water pump, but it may be more cost-effective to buy a complete replacement water pump if they are available.

In either case, the water pump needs to be removed and replaced so that it has a fresh set of bearings.

Worn bearings can eventually fail, which may stop the water pump from turning. When that happens, it may overheat your car and cause significant damage to the engine.

Please also read: Grinding Noise While Accelerating & Braking? 5 Reasons (Solved)

#4 – Your Engine Accessory Belt Is Slipping

The accessory belt on your engine turns the pulleys connected to the alternator, air pump, power steering pump, and water pump.

The belt should make strong contact with each of the pulleys without slipping or making a squealing sound. If the water pump pulley slips with the belt, it can cause your car to run hotter than normal or overheat.

How to Fix It

If the accessory belt is slipping, the belt or the water pump is the problem. You can check the belt’s condition by visually looking for cracks in the belt surface or significant wear in the belt.

If the belt is worn, it should be replaced. If it is slipping on the water pump, it should also slip on every other pulley in the system.

Worn bearings and seals in the water pump can prevent the impeller shaft from spinning, and subsequently, the belt slipping on the pulley. If the water pump impeller won’t spin, the water pump should be rebuilt or replaced.

You may also see a Check Engine Light (CEL) illuminated in the gauge cluster indicating trouble code P0087 has been recorded for a faulty water pump.

#5 – Your Water Pump Pulley Is Loose And Making A Rattling Sound

The pulley attached to the water pump is either held by a tight fit or by fasteners. The extremely tight fit can be worn over time and means the will pulley spin on the impeller shaft.

This can cause the water pump to lose efficiency and make a rattling noise. Loose fasteners holding the pulley on will also rattle loud enough for you to hear.

How to Fix It

If the pulley is held onto the water pump impeller with a press fit condition, a worn-out situation means the water pump or the pulley should be rebuilt or replaced.

If the material on one or both of them has been worn away preventing the tight-fitting condition, it can’t be repaired. If the fasteners are loose, they should be tightened to the manufacturer’s recommended torque.

#6 – The Water Pump Impeller Is Spinning The Wrong Direction

It may sound crazy, but the water pump impeller can spin in the wrong direction. It doesn’t happen often, and it’s usually because the wrong water pump is put on the engine.

Many manufacturers are notorious for using the same engine in multiple cars. You might even get a crossover between associated brands too.

The water pump impeller should turn clockwise or counterclockwise to match the spin of the accessory belt on the engine.

How to Fix It

There isn’t a simple way to make the impeller spin in the opposite direction to push the coolant through the cooling system correctly.

You may be able to find a rebuild kit to match the engine in your car, but it may be easier to buy a new (and correct) water pump for your car. Always double-check the application and the correct direction the engine turns when buying a new water pump.

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