Having water in the gas tank can degrade the engine’s performance by seriously affecting other parts like the fuel pipeline and its injectors. However, if timely attention is not given to the problem, it may eventually damage the car’s engine.
Therefore, it is pivotal to locate the water in gas tank symptoms and seek the essential maintenance tips that can save the engine from getting damaged.
How does water get in a gas tank?
The following are the major ways water can drip into a gas tank;
Intrusion of water
Rainwater can easily enter the fuel tank if you forget to close the fuel door after refueling your car. If the gas tank has a puncture in it, it will allow water penetration into it.
Low-quality gas
The presence of low-quality gas in a fuel tank is another cause of this problem; it can be due to a damaged water filter from the gas station you normally fill up your gas tank. A damaged filter implies that the fuel pumped into your gas tank has some water content.
Condensation
It has been researched that an environment with a humid weather condition with a significant temperature change can cause 0.81 Oz (0.0296 liters) of water vapor to be formed in an empty gas tank of about 190 gallons of fuel capacity.
The water vapor will condense into water and may even develop to a high volume if the water is not removed from the tank.
The gas produced by the refinery
It is not a common factor, but there is a certain level of possibility. If there is a malfunction in any machine in the refinery whose job is to prevent a mixture of water with the gas, it will lead to poor quality fuel at the gas stations.
Faulty top fuel pump
Some modern cars have their fuel pump installed on top of the fuel tank, seen under the front seats.
These cars are more prone to have this issue because if the fuel pump seals are damaged, it can result in a high accumulation of water in the fuel tank, especially when the car passes through deep floods.
Symptoms of water in a gas tank
The main symptoms of water in the gas tank include:
- Rough acceleration
- Misfires
- Rough idle
- Check engine light
- Steam from the exhaust
- Slow acceleration
- Hard starting condition
- The engine does not start at all
- The problems appear after the car has been standing for a while
Here is a more comprehensive list of the symptoms of water in the gas tank that you should look out for:
#1. Rough acceleration.
The most common symptom of water in the gas tank is probably rough or shaky acceleration. Since the engine is treating water in the gas tank as fuel, the air-fuel mixture through the combustion chamber will be very strange.
#2. Misfires.
Due to the situations I explained earlier of what will happen when the water makes it into the combustion chamber, you are probably going to notice misfires when the water is in the combustion chamber of the cylinder.
Misfires and rough acceleration can be two pretty similar symptoms, as misfires can cause rough acceleration, but you can also notice the misfires when the vehicle is just idling.
#3. Rough idle.
Rough idle is also going to be a common symptom due to the faulty air-fuel ratio and the misfires. The car is very sensitive to small mistakes at idle, and it is at idle when you will notice most of the symptoms of water in the gas tank.
#4. Check engine light.
Modern cars have continuous monitoring of all of the engine’s sensors. If a sensor is giving a faulty value, it sends it to the engine control unit, where it will save a trouble code in the memory, and if it is serious enough, it will sometimes turn the check engine light on.
If your check engine light is on your dash, it is most definitely urgent to check the trouble codes with an OBD2 scanner.
#5. Exhaust steam.
When you have water in the combustion chamber or exhaust pipe, heated water vapor will combine with exhaust, and turn to steam.
We all know what happens if you cook water above boiling point of 100°C – it will evaporate to steam. Steam is water vapor, therefore if you see a lot more steam is coming out of the exhaust pipe, then there may be water in the gas tank.
#6. Slow Acceleration.
All the sensors in the car are made to ensure the air-fuel mixture is at a perfect mix at all times. For example, if a water molecule go’s through the engine which the sensors read as a fuel molecule, then this causes the air-fuel mixture to run too rich, or umbrages as lean.
These effects can also come as power reductions, and you may see symptoms such as slow acceleration.
#7. Hard start condition.
The startup moment of any car engine is very crucial. The fuel mixture must be close to perfect, or the spark plug will not receive enough fuel to ignite the fuel, or it may be drowned to a point where it cannot ignite at all.
Water in the gas tank will disturb the fragile balance, and you could have complications with the start of your engine. If you have long cranking period then fuel in the gas tank could be something to keep on your list of things to check.
#8. The engine does not start at all.
It is possible to have enough water that the engine will not reach ignition at all. You also have the possibility if it won’t crank, it is hydro-locked, that you may have hydro lock.
Water is not compressible like air, so when the piston is trying to compress the air mixture, it will be trying to compress water into the combustion chamber, and this is not possible.
This will create icing up of the engine, and may have also caused damage such as bruising crankshaft rods.
This is not common, and there would have to be plenty of water in the combustion chamber for this to occur. If you think this is the case, to ensure it is possible to turn the crankshaft, to make sure, remove one spark plug demonstrating issue.
#9. The problems after the car has sat for a while.
When the car sits for a while. The fuel floats on top of the water, and when the fuel is used, and the water remains to the bottom of the tank. When the fuel pump pumps, the fuel turn water from the ignition chamber.
If your vehicle is sitting, the water will stay at the bottom of the tank and if your fuel pump will suck the fuel from the bottom of the tank, and if your car is sitting, your fuel pump will only suck water to the engine.
Causes Of Water Entering the Gas Tank
Understanding how water enters your fuel system can help prevent future problems:
- Contaminated Fuel from Gas Stations: Some gas stations don’t properly maintain their underground storage tanks, allowing water to seep in. Heavy rains can sometimes infiltrate older or poorly maintained tanks.
- Condensation: Natural condensation occurs in partially filled gas tanks, especially with temperature fluctuations. When warm air inside the tank cools, water vapor can condense on the tank walls and drip into your fuel.
- Faulty Gas Cap: A damaged or missing gas cap can allow moisture to enter your fuel tank. The rubber seal on gas caps deteriorates over time, compromising its ability to keep water out.
- Intentional Contamination: Unfortunately, vandalism where someone deliberately adds water to a gas tank does occur. This is one reason to consider a locking gas cap.
- Improper Fuel Storage: If you store fuel in containers for extended periods, condensation can build up, especially if containers aren’t filled completely or sealed properly.
How to Confirm There’s Water in the Gas Tank?
There are many signs which can show that things are not well with your fuel tank. Below find some of the symptoms that can occur when there is water in the fuel tank.
#1. Hydrolock.
When this happens, you cannot start the engine of your car. This means that water has entered the combustion chamber and prevented compression and combustion of the gas.
#2. Engine Starts But Stops.
The engine of your car may start when you turn the key, but will soon stop. This could imply that the water inside has made the combustion weaker than what is required. You need to remove water from the tank and do some maintenance.
#3. The Engine Does Not Start At All.
In this case, the engine stops responding even if the ignition remains on. But a lack of gas could also be a reason that the engine does not start.
#4. Reduced Fuel Economy.
Water in the gas tank reduces the power of the engine. While the amount of gas burned remains the same, you get less mileage from your car. In the end, you will consume more on fuel without getting the right value.
Apart from that, water will settle at the bottom of the tank as it is more substantial than gasoline. This can rust your fuel tank.
Water in a fuel tank too makes a car to lose its power. It results in the fuel biodegradation. Microbial growth could block the filters and cause the entire fuel system to collapse.
#5. Reduced Acceleration Speed.
You can also experience subtle speed changes that you do not implement while driving. This can also get the form of a sputtering.
If you have adequate fuel, but it still stutters when you step on the accelerator, at that point, consider checking if your fuel is water polluted.
How Much Water in a Gas Tank is Bad?
Water in your gas tank is never a good thing. But if there are only trace amounts of water mixed in with the fuel, you may be able to combat the problem by adding dry gas (isopropyl) to your gas tank.
Dry gas is a product that can help restore combustive properties to gasoline-contaminated water.
Meanwhile, a significant amount of water will usually require draining the fuel tank. You may also end up having to service other parts of the fuel system, especially if you continue driving with water-contaminated fuel.
When in doubt, it’s best to have your vehicle looked at by a professional mechanic right away.
Effects of water in the gas tank
It can damage the fuel injector
Refusal to remove the water in the gas tank can permanently damage the injector. Accumulation of water in the gas tank can cause corrosion of the injector and the entire fuel system.
It will cause the fuel system to fail and prevent the engine from starting, which means you will not drive the car.
Reduction in the efficiency of the accelerator
When driving a car that has high water content in its gas tank, that vehicle may hesitate when pressing down the accelerator, or it may even start jerking. You will be unable to drive smoothly on a highway as a result of this issue.
You might also experience sudden fluctuations in the speed of your car while driving. It will make your vehicle very difficult and not safe to drive.
It damages the whole fuel system
Since gasoline has a lighter weight than water, the fuel will set to settle at the top of the gas tank while the water will settle at the tank’s bottom.
Vehicles that pump gas from the bottom of the tank may pump water into the engine, and also, the presence of water at the bottom of the gas tank can lead to rusting and damage to the hoses and pipes that transport the gas.
The ignition system of the car will not be able to function
It will not be possible to start your car at all when you have a high volume of water in your gas tank, or you have left water in it for too long. Most times, it looks as if there is no fuel in the tank because as you try to start the car immediately, it goes off.
Damage to the engine
The pumping of water to the engine system can completely damage your car’s engine because it cannot undergo water combustion. It will damage the various parts of the entire engine and might lead to a permanent shut-down.
How do you fix the water in a gas tank?
After understanding all the water in gas tank symptoms, now it’s time to get rid of the water in the fuel system.
In this regard, one of the best and easiest solutions is to replace the entire gas within the reservoir.
This can be done by replacing the old fuel with a whole new high-quality gas that has no ethanol in it. The reason behind using this gas is its property of not absorbing water.
However, if you feel that it’s an expensive process, then there are certainly other steps: how to get water out of gas tank:
#1. Use octane booster.
Once you find the symptoms of water in the gas, you can exhaust it completely by using a high-level octane booster inside the gas reservoir.
Once injected, it would absorb all the moisture or water inside the tank, thus leaving it completely dry.
#2. Put special fuel additives and methanol.
No doubt, it is a less reliable solution when there is more water in the gas tank. But, if it’s only the moisture, then you can make use of these fuel driers, which are actually special fuel additives and methanol. Some of the fuel additives examples are Dri-Gas, DFS Plus, and Heet.
Information: Certain fuel driers use special agents to protect the sensitive material of old vehicles, whereas others simply use alcohol to remove the water. So, always think and look for the product specification prior to its purchase.
#3. Make use of new filters.
In case the water content inside the vehicle’s gas container is too high, then you not only have to replace the fuel but also the filters.
Tip: For all the above steps, it is suggested to take assistance from professionals unless you are aware of what you are doing with the vehicle.
Preventing Fuel Tank Water Contamination
Prevention is always easier and less expensive than dealing with contamination after it occurs:
Regular Maintenance
- Keep your tank at least half full when possible to reduce condensation space
- Use fuel stabilizer when storing vehicles for extended periods
- Replace your fuel filter according to manufacturer recommendations
- Inspect your gas cap seal periodically and replace if damaged
- Add a preventative water-removing additive during high-humidity seasons
Fuel Sources
- Purchase fuel from high-volume, reputable stations where fuel turns over frequently
- Avoid filling up right after a fuel delivery to the station, when sediment may be stirred up
- Consider fuel quality testing if you suspect a particular station has water issues
- Be cautious after heavy rain in areas where station tanks might be compromised
Storage Considerations
- Park in covered areas when possible to prevent water entry through the fuel system vents
- For seasonal vehicles, fill the tank completely before storage to minimize condensation space
- Consider a fuel stabilizer with water remover for vehicles that sit for extended periods
- For boats and outdoor equipment, use specialized marine-grade water separators
| Prevention Strategy | Effectiveness | Ideal For |
|---|---|---|
| Keeping tank above half full | High | All vehicles, especially in humid climates |
| Preventative additives | Medium | Seasonal vehicles, older vehicles |
| Water separator installation | Very High | Diesel engines, boats, frequently affected vehicles |
| Quality fuel sources | High | All vehicles |
| Indoor/covered storage | Medium | Vehicles stored long-term |
How Much Does It Cost to Fix a Car With Water in the Gas Tank?
Most professional mechanics will charge somewhere between $300-800 for a complete fuel system drain and flush if there’s no extended damage (depending on your vehicle’s make/model and where you have it services.
It’s not necessarily cheap but much cheaper than repairing engine components damaged by long-term water exposure. The key is to catch and address the problem early on before additional fuel system components are affected.
If the water contamination has caused more extensive damage, you might face these additional repair costs:
Professional Repairs (Additional Costs)
- Fuel injector cleaning/replacement: $350-1,200
- Replacing fuel pump (if damaged): $300-1,000
- Fuel pressure regulator replacement: $150-500
- Spark plug replacement (if fouled): $100-300
- Worst-case scenario (engine damage repair): $1,500-4,000+
DIY Solutions
- Fuel additives: $5-15 per bottle
- Basic fuel filter replacement: $15-30 for parts
- Fuel tank drainage supplies: $20-50
FAQs.
Q: Can a Rusty Tank Be Cleaned and Repaired?
When the water in your gas tank has caused it to rust, you may be wondering if it can be cleaned and repaired.
The answer is yes, but it is important to take your car to a mechanic as soon as possible. Rust can cause serious damage to your engine, so it is important to get it fixed as soon as possible.
Q: Do I Have to Replace My Gas Tank If It Has Water in It?
In case the water in your gas tank has caused serious damage, you may need to replace it. However, if the damage is not too severe, a mechanic may be able to clean and repair your gas tank.
Q: Is Rough Acceleration a Symptom of Water in Gas Tank?
You may notice that your car is accelerating roughly if you have water in your gas tank. This is because water can cause corrosion and rust, which can damage the engine.
Q: Can Additives Help to Remove Water From Gas Tank?
There are a few additives that you can add to your gas tank that may help to remove water. However, it is important to take your car to a mechanic as soon as possible. They will be able to drain the water from the tank and inspect it for damage.
Q: Can I Drive My Car If It Has Water in the Gas Tank?
Again, it is not recommended to drive your car if it has water in the gas tank. Water can cause serious damage to your engine, so it is best to take your car to a mechanic immediately.
Q: How Long Does It Take for Water to Cause Damage to My Car?
Water can cause damage to your car almost immediately. However, the amount of damage depends on how much water is in the gas tank. If you have a lot of water in your tank, it can cause serious damage to your engine.
Q: Are There any DIY Fixes for Water in the Gas Tank?
There are a few things you can do to prevent water from getting into your gas tank. First, if you live in an area with high humidity, try to park your car in a garage or covered area.
This will help to keep the air around your car dry and prevent water from condensing inside the gas tank.
But if you live in an area with a lot of rain, check your gas tank regularly for cracks or holes. In case you find any, have them repaired as soon as possible.
Conclusion
The engine is the most vital and most expensive car component, so appropriate attention is needed to prevent it from getting damaged. Water presence in a fuel tank can damage the whole engine system, so it should not be left long in the gas tank.
Be aware of how water can enter your gas tank and take the necessary measures to prevent it.
But immediately, you notice any of the symptoms mentioned that indicate water gas in the tank. Make sure you take the most appropriate measure to fix the water in the gas tank completely.