What Are The Signs Of a Bad Water Pump?

What are the signs of a bad water pump? Many different parts of your vehicle actually have ways of letting you know that they’re going to fail. The water pump is one of them. When a water pump starts to fail, the seals go bad first and if you let it go for a long, the bearing surfaces will start to go bad and then you can have a total failure.

But, once the seals go bad, there is a little hole in the water pump that is designed to start leaking coolant past the seals. You will see coolant spraying around your engine or dripping down. That is the first way of your water pump tells you that it is going to fail. That is not the only sign. So, what are the signs of a bad water pump?

”The most common signs of a bad water pump are coolant leaking underneath the water pump, growling and metallic noise coming from the water pump, engine overheating, seized water pump, and burning rubber smell coming from the engine bay.”

What Are The Signs Of a Bad Water Pump?

There are four most common signs of a bad water pump. If you notice any of these signs on your vehicle, make sure to take your vehicle to the repair shop. It’s better to fix it immediately before more damage is done.

1. Coolant leaks underneath the water pump

What Are The Signs Of a Bad Water Pump?

When the water pump is faulty due to the metal impeller being eaten by the acidic coolant or the plastic impeller structure being changed by the heat, a coolant can start leaking from the pump. You will notice a puddle of coolant underneath your vehicle. If you do notice a coolant leak underneath your vehicle, open up the hood, and investigate further. If the water pump is faulty, the coolant should be leaking right where the pump is located in the engine.

The water pump in most cases is driven by the serpentine belt. Because it is connected to the serpentine belt, the water pump and its components like the impeller to be specific, rotates with the speed of the engine. The impeller inside the water pump can be made out of metal and plastic.

Sometimes, if the coolant gets acidic, it will eat the fins off of the metal impellers and the water pump. A new coolant can last from 2 to 5 years. If you don’t change your coolant for a long period of time it will get acidicOpens in a new tab.

When it comes to plastic impellers, they do an excellent job until you put it under a load where things get hot. Because of the heat, the plastic expands. The shafts inside the water pump start to spin slower than it is supposed to or is not moving at all.

2. Growling and metallic noise coming from the water pump

If you notice any growling and metallic noise coming from the engine bay, specifically from the water pump, this is a sign that the bearing inside the water pump is worn. The bad news is that you cannot replace only the bearing, you need to replace the whole water pump.

Before you replace any parts, you should be 100% positive about the source of the growling noise. Locate the water pump and touch it with a long screwdriver. If the water pump is faulty, you will hear the growling and metallic noise, but also you should feel a strong vibration through the screwdriver.

Also, you can remove the serpentine belt and try to spin the water pump pulley. See if it’s making any growling noise. Before you remove the serpentine belt, make sure to disconnect the battery. The alternator will be close to the water pump and for safety reasons you don’t want to fry anything. If the water pump pulley is making a growling noise while you spin it, then you need to replace the water pump.

3. Engine overheating

Engine overheating

When the water pump seal is worn, the coolant will rapidly leakOpens in a new tab.

After you made a positive diagnostic that your water pump is faulty and you’ve replaced it, make sure to check the cooling system components for any damage.

When an engine overheats, it is not only that engine that suffers the damage. The increased temperature can create weak spots in the radiator, the radiator hoses, and the thermostat. You should check for any possible leaks on the radiator, and the radiator hoses. Also, look for the possible stuck closed thermostat.

4. Seized water pump and burning rubber smell

Seized water pump and burning rubber smell

A seized water pump can cause the serpentine belt to slip off the pulley or it can cause the serpentine belt to burn. The burning smell is caused by the belt rubbing against the seized water pump pulley since it is not rotating anymore.

You need to locate the water pump and remove the serpentine belt. Try rotating the water pump pulley. If it does not spin, the water pump is seized. If your water pump is driven by a timing belt, a seized water pump usually causes the timing belt to skip a few teeth. You won’t be able to start your vehicle.

Can the Water Pump Be Repaired

The water pump can be repaired but not many people are doing that. When the mechanic tells you that your water pump is bad, it is best if you replace it with a new one. A repaired water pump will never be as good as new one. It is an important part that you really need it working 100%. The water pump itself costs around $50 to $150. The mechanic will charge you from $300 to $500 for labor. This will depend on the location of the water pump. Many components need to be removed in order to reach the water pump.

Bob Semana

Hi there, I am a Mechanical Engineer that specializes in AC, Alternators, Batteries, Cooling systems, and Drive Train issues.

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