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How To Fix a Flooded Engine: How Long To Wait?

Water is one of the worst elements your car can be exposed to, especially if it seeps through the engine because of the damages it can cause. There is a workaround to troubleshoot a water-flooded engine, but time is of the essence, so you have to do it ASAP. You can fix the issue on your own or contact a professional mechanic to do it.

So, how do you fix a flooded engine, and when can you use the car again? The certainty of fixing water-submerged engines is low. Most are unfixable due to major damages and prolonged and deep submersion. For minor issues, though, once it’s water-free and troubleshot properly, you can use it already.

If your car was submerged in floodwater or bodies of water, always remember that you must not insert the key in your car’s ignition and attempt to start it. If it’s salt-free water, you will find the solutions below helpful. You will find ways to drain the water out of your car, dry it out, and start your car once you’ve done fixing the issues.

Mud-Covered Jeep

What Happens if Water Gets in Your Motor?

If water finds its way to your vehicle’s engine, especially for extended periods, the worst damages you can expect include:


Hydrolock is a condition wherein a high amount of water enters your car engine’s cylinders. At this point, it will cause damages to not only the cylinders but also the pistons. These damages become worst when you start your engine.

If you’re lucky, a professional might still be able to fix the damage but, of course, would cost you more money than when fixing minor issues. Unfortunately, most hyrdrolocked engines lead to a car being totaled completely.

Electrical Problems

It’s common knowledge that electricity and water don’t work together. Your car engine has many electrical parts such as the battery, alternator, and wires. They can get damaged when exposed to water for a long time. They can also cause electrocution or even fire when not handled well or when handled while wet.

Rust Formation

Like electricity, metal and water do not work together. Most car engines, especially old models, still have metal parts that will rust on the surface when exposed to water and not immediately dried out.

Now that you have an idea of the worst-case scenario for a flooded car engine, as soon as you find out that your car has been submerged in water, you must move it out of the water without starting the engine. Then, begin doing what’s necessary, and that is what you’ll learn next.

How To Fix a Water Flooded Engine

Below are the steps recommended by most experts that you need to take when your car engine was exposed to salt-free water.

1. Safety First!

Before doing anything to your car, make sure to disconnect the battery to prevent electric shocks. Remove your engine’s plastic cover, and then as much as possible, dry every part with a clean, shop towel.

2. Remove Any Water and Ventilate Your Car

Apparently, your car’s engine isn’t the only thing you need to worry about if your car was submerged in water. So, before the actual steps you need to take on how to fix a flooded engine, you need to drain out any water present inside your vehicle. Then, ventilate the car to prevent mold growth, rust, and other damages commonly caused by water.

How To Remove Water

For puddles of water in your vehicle, you can use a wet or wet-dry vacuum cleaner to suck the water out. If you have a car vacuum cleaner that converts to a blower (Check Amazon for Price), all the better since the blower can help speed up the drying process and remove wet and dry debris. You can also consider placing used towels or cloth to absorb the water.

Lastly, you can opt to remove your car’s carpet since you can either re-install or replace it with a new carpet or other alternatives. Then, all you have to do is help the water find its way to the car floor’s drain holes.

How To Ventilate Your Car’s Interior

Once you successfully removed the water, roll down the windows (skip if you have power windows since, again, you shouldn’t attempt to start your car), open the doors, and let air and/or sunlight help your car dry out. You can also switch a standing or table fan and direct it toward your car. It’s also best to remove the seats and allow them to dry separately; this way, they’ll dry quickly.

3. Inspect Engine Parts and Fix the Issues

While you’re ventilating your car, simultaneously check the engine parts for the presence of water, and if possible, fix the issues.

Gas or Fuel Tank

If you have a water-flooded car engine, the possibility of your fuel system having water is high. What you need to do is siphon out a little amount of gas from the gas tank bottom. If you see a water-oil mixture upon inspection of the siphoned fuel, drain your car’s fuel system.

How To Drain the Fuel System

Since you can’t start or drive your car at the moment to empty the fuel tank, you have to drain the fuel tank no matter how much fuel is still in it. There are two methods to do so, and they are:

Using a Siphon Pump

For this technique, you would need the following

  • Siphon hand pump
  • Long, thin screwdriver
  • Storage can
  • Rag/s

The steps you need to take are:

1. Feed the siphon pump’s tube into your car’s gas tank by:

  • Opening the fuel filler door and remove the cap.
  • Feeding one end of the siphon tube down through the filler neck, one small increment at a time, until it reaches the tank’s lowest part. If your car has a tiny metal door that might keep the tube from being fed to the tank, slowly push the door open using a screwdriver before continuing to push the tubing down.
  • Use the rag to wipe off any spilled oil.

2. Pump the fuel by:

  • Feeding the tube’s other end into the tank and then pumping its hand pump until fuel moves to the tube.
  • Continuing to pump until you fully drain the fuel or see fuel moving through the siphon pump’s tube.

3. Dispose of the pumped fuel properly. You can contact any recycling and waste disposing centers in your area.

Through Your Gas Tank’s Drain Plug

Draining the contaminated fuel through your vehicle’s gas tank would require you to have the following items on hand:

  • Basic hand toolset
  • Drain pan
  • Jack stands and jack
  • Tire chocks or wood blocks
  • Safety goggles or glasses
  • Rag/s

Here’s what you need to do:

  1. Slowly and safely raise one of your vehicle’s rear wheels to a level comfortable for you to work around underneath.
  2. Secure it on a jack stand or jack.
  3. Set your car to a parking brake.
  4. Place chocks or blocks under your vehicle’s tires.
  5. Put your safety goggles or glasses on, and then look for your car’s drain plug underneath the vehicle. You can usually find it at the gas tank’s bottom.
  6. Place the drain pan underneath the drain plug and loosen your car’s drain plug. For some vehicles, you might need a ratchet and a socket to do so.
  7. Remove the drain plug completely and let the fuel drain into the pan. Use the rag to wipe off any spills.
  8. Once you drain the contaminated fuel completely, re-install your car’s drain plug.
  9. Dispose of the pumped fuel properly. You can contact any recycling and waste disposing centers in your area.

Electrical System

For your car’s electrical system, the only solution is to replace any part submerged in water to ensure your safety. Usually, if the electrical part is below the flood water line, it needs a replacement. For the connectors, you can remove them and allow them to dry.

Fluid Reservoirs and Filters

To check if your car engine has water contamination, check the dipsticks for both the engine and transmission. If water droplets cling to the dipstick/s, then you must change the oil and replace the oil filter. A wet air filter also denotes that your engine has water, so replace it, too. You should also replace them after a few hundred miles of driving your car.

It’s also wise to check your car’s fluid reservoir for power steering, coolant, and brake if water seeped through. If it did, flush the fluid out and replace it.

If your engine was submerged in muddy water, it’s a must for you to remove the engine’s oil pan and wash it to ensure you clean any debris or dirt. Once you’re done doing all of these, you can begin cranking your car. If you want to be more certain, though, you can consider using a dual-lens inspection camera (view on Amazon) to check the engine.

How To Start a Flooded Engine

Once you’ve done the steps above and sure that you’ve drained all water or most of it, you can do the following:

  1. Unplug your car’s spark plugs and ignition coils for the water to eject through your car’s exhaust system and engine head.
  2. Slowly crank your engine, ensuring the water sprays out of it.
  3. Stop and spray a little amount of oil in the cylinders and then crank again.
  4. Repeat for about four to five times or when you no longer see any signs of water or the oil doesn’t appear milky or cloudy. At this point, you can put the coils and plugs back.
  5. Start your car and if the engine starts running, let it do so for a few minutes and then shut it off.
  6. Check your car’s oil. If it still looks a little milky or cloudy, a little water might still be present so consider changing the oil and filters again.
  7. Then repeat the whole process.

Conclusion: How To Fix a Flooded Engine and How Long To Wait

Bringing your water-submerged car to a professional to repair it is the best option to ensure your safety and for you not to make matters worst. That said, anyone with basic car troubleshooting knowledge and skills can perform the provided procedures on how to fix a flooded engine and how to start a flooded engine.

If you’re unsure and have zero knowledge, you can contact a professional and perform the drying out and ventilating procedures while waiting. Just make sure you don’t start your car engine because, as per “flooded engine how long to wait” guidelines, you must only try to do so once everything has been inspected, drained, and dried, as well as once certain parts have been replaced. Lastly, even if you have an off-road vehicle, like a Wrangler, a little protection with the help of a waterproof cover (view on Amazon) while it’s parked can minimize or prevent water entry.