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Can Water Cause Misfire? (Bad Water Pump, Water in Gas, Etc)

Water and gasoline don’t mix, rather the gas floats on the water. Water can enter your gas tank for various reasons but your car may not tolerate that. It causes several damages to the whole internal system as well as the engine. 

If you’re a new driver you must know the symptoms and what they can bring.

Can water in a gas tank cause misfire?

Water in a gas tank can cause a misfire if the water goes into the combustion chamber. Water can damage the injectors and the whole internal combustion. Spark plugs may not work properly and it’ll result in misfiring, so the engine will be in great trouble.

Water can enter the fuel tank for many reasons. Such as a damaged fuel pump or condensation outside for temperature or humidity or faulty gas pump or rain that stored in the gas storage tank or carelessness while washing the car etc. 

Water can help to enter more water in the car. Wherever the water comes from, your car will surely face problems or at even worse, it might get trouble to the engine.

When the water reaches the combustion chamber it’ll increase the friction and cause cylinder misfires. 

The whole internal combustion will be damaged by the enormous heat and the car will not work as smoothly as before. Water can dilute the lubricant and damage the engine mechanically.

The spark plugs may not work correctly if their engine misfires and the driver can notice some irregular symptoms. Jerking while accelerating, shaking or vibrating, loud sound from underneath hood or injectors, exhausting smokes, or the smell of fuel is noticeable.

 It’ll be difficult to start your car and run your car and cause bucking and stalling. If the ignition components are working properly as well as the spark plugs you may still run your car a little bit normally but as soon as you notice the misfire you should take help.

What are the symptoms of water in your gas tank?

This water will cause low performance of your car and you may not drive smoothly as you could before. You can face jerking, vibrating, and loud sound of injectors. The water may damage the engine and you might face these symptoms:

Trouble Accelerate:

If your car’s engine is misfiring you’re going to have difficulties reaching enough speed. You’ll get a slow response to engage in acceleration. You might experience jerking, shaking, and vibrating while driving.

Rough Idling:

While misfiring, your car will behave in a rough manner. The engine might behave like jumping up and down and you’ll experience bumpy driving.

Smell of fuel:

Fuel consumption will rise because of the water. As a result, you might notice the strong smell of fuel.

Black exhaust:

While misfiring, your vehicle’s emission increases. It’s giving you the signal that the process of passing air and fuel is not working properly. As a result, it’ll create black exhaust.

Loud sound:

You might notice a loud sound from the injectors or engine’s sudden sound change. It’s the signal that the whole combustion chamber is affected by the water.

Difficult to start the engine:

If you start driving after quite a long time, it’ll not work as before. The car might not start again, or if it starts it’ll not run smoothly or at enough speed.

How long does it take for water to ruin a gas tank?

It depends on how much water entered your gas tank. If there’s a little water like a few drops, you may not get enough symptoms. All you will need is an additive that’ll help to dry up the water. 

But if the amount of water is more you will need to get help from the mechanics to remove the fuel tank and add new filters.

A small cup of water or any amount more than that is going to affect your vehicle. You shouldn’t take the risk to drive your car without removing the water. If a lot of water entered the engine, you might lose the engine within 10 seconds.

How much water can ruin a gas tank?

From a cup of water to a large amount of water both can be serious to ruin a gas tank

If you find your car is not starting, jerking while accelerating, vibrating or a loud voice coming from underneath the hood, you have to understand these are the symptoms of misfiring caused by the water.

A very small amount of water, such as a drop or two can be found naturally in a gas tank and you should not be worried regarding that as they will dry up along with time. But more water like a full cup of tea can be serious to your car’s engine health. 

It needs to clean up the water as soon as possible depending on the amount of water or it may cause rust and corrosion to the engine.

How to check for water in a gas tank? 

To check the water in the gas tank, you need a clear jar. From the fuel filter, you have to dump the active gasoline into that clear jar and rest it for a few minutes to settle. After a while, you may notice a layer coming out if there’s water in your gas tank.

If you find the fuel is clear and purely amber, your gas tank is water-free. If you notice a clear bubble at the end of the jar, you’ll be clear that there’s water in your gas tank. 

While phase separation by the siphon, If you notice bubbles are gelatinous white, then it might be because of the ethanol and water mixing. And you’ll need to take help from the mechanics immediately.

Can a bad water pump cause a misfire?

A bad water pump can cause misfires as it can cause drastic damages to the engine system. If the engine is overheated it may cause a blown head gasket that results in a misfire. The spark plugs can’t work properly and if the coolant gets on the spark plug wire, it may cause misfiring.

The water pump is a very important component that assures the consistent flow of the coolant. It’s designed with other cooling systems that resist engines from getting blocked. It helps a car to run smoothly at an average temperature. 

You can speed how much you want to or you can travel how far you want to properly.

But when the water pump is leaking, the engine system will be in great trouble. There will be a drastic change in the whole system. The engine will be overheated that’ll cause a blown head gasket. The result will turn into a misfire and affect the engine’s health.

The water of the internal combustion chamber will increase the friction and damage the engine mechanically. The ignition components as well as the spark plugs may not work properly because of the water entered by the bad water pump. 

When the coolant gets on the spark plug wire it will result in misfiring and cause unusual activities.

What problems can a bad water pump cause?

To ensure a consistent flow of the coolant water pump is a very important component. If the water pump is leaked for any reason, it can bring some problems like:


Leaked water pump can’t consistently make the flow of the coolant. The main purpose of the water pump is to help the cooling system and help the engine not get blocked. 

But as it fails to do so, the engine will overheat and can do serious damage to the engine.

Coolant leaks:

If the coolant is leaked the radiator fluid will start to leak from the front of your car. It’s a sign that it had to be changed as soon as possible or it may harm the engine.

Loud sound:

You are going to notice a high-pitched whining sound from the underneath hood which is giving a signal of the affected combustion chamber and leaked water pump.

Black exhaust and smell of fuel:

You might notice black smoke exhausting from your engine and a strong smell of fuel. This is because of the increase of emissions and the process of passing air and fuel is affected.

Can you drive a car with a leaky water pump? How long can you drive a car with a bad water pump?

Yes, you can drive your car with a leaky water pump but for likely 5 to 20 miles. But it’s not recommended because there are few risks. For the leaky water pump, the constant cooling flow is hampered and so it results in overheating the vehicle’s engine.

You may face jerking while accelerating, vibrating, black exhaust, the smell of fuel because of the water causing misfiring. You should change the water pump as soon as possible or it might get trouble for your car engine.

Final Thoughts

When the water enters the combustion chamber, it can cause misfire and damage whole internal combustion systems. A bad water pump is one of the reasons that cause misfires as it blows the head gasket overheating the engine. Misfire can cause rust and corrosion and even damage the engine system.