Does auto insurance cover hydrolock?

Does auto insurance cover hydrolock? While a hydrolocked engine is covered by insurance, you need the comprehensive coverage to be eligible to file a hydrlocked engine insurance claim.

UPDATED: May 26, 2022Fact Checked

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Sara Routhier, Managing Editor and Outreach Director, has professional experience as an educator, SEO specialist, and content marketer. She has over five years of experience in the insurance industry. As a researcher, data nerd, writer, and editor she strives to curate educational, enlightening articles that provide you with the must-know facts and best-kept secrets within the overwhelming world o...

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Written by Sara Routhier
Director of Outreach Sara Routhier

Cynthia Lanctot is an insurance professional with ten years of industry experience. Cynthia is licensed in several states, and holds an associate in claims law, as well as a bachelor’s degree in English. Cynthia’s experience includes the New England and Northeast states. She currently works as a liability claims professional and an occasional online contributor.

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Reviewed by Cynthia Lanctot
Licensed Agent Cynthia Lanctot

UPDATED: May 26, 2022

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Fact Source
Hydrolocking is usually caused by people driving through large
Hydrolocking can also occur due to a cold air intake
Hydrolocking is when an engine either seizes or fails due to water in the
Water entering a combustion engine causes many unseen
The first sign of hydrolocking is when your engine stops
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Things To Remember

  • Your engine will hydrolock if water enters a cylinder and prevents the pistons from working correctly
  • Insurance will cover a hydrolocked engine as long as the damage was not intentional or due to poor vehicle maintenance
  • You need comprehensive coverage to have a hydrolocked engine fixed because collision and liability do not cover it


Does auto insurance cover hydrolock? What even does a hydrolocked engine mean?

Imagine driving down the road, and your car suddenly starts sputtering. You hear a loud thunk, and your engine shuts down. No matter how hard you try to restart the vehicle, the engine won’t turn over.

A hydrolock occurs when water enters your engine and prevents pistons from working properly. If your car is parked when it happens, your engine will probably come out relatively unscathed. However, if you’re driving, your engine could face catastrophic damage.

Luckily, a hydrolocked engine is covered by comprehensive car insurance as long as the damage was unintentional.

Read on to learn how a hydrolocked engine is covered by insurance and what coverage you need to protect your car. Then, compare quotes with as many insurance companies as possible to find the best rates possible.

In the meantime, feel free to type your ZIP code into our helpful tool above to find rates in your area from insurers who will help with a hydrolocked automobile.

What is a hydrolocked engine?

A hydrostatic lock — or hydrolock for short — occurs when fluid prevents your engine’s pistons from reaching the top of their strokes. Understanding a combustion engine (see might seem confusing, but the process is relatively simple.

An engine becomes hydrolocked when liquid gets into one or more cylinders, but it won’t lock down unless there’s enough fluid to prevent the piston from reaching the top of its chamber. Once a piston can’t reach its uppermost stroke, it abruptly stops.

Unfortunately, one piston stopping does the same to the others. When that happens, your engine shuts down and is officially hydrolocked.

While most engines hydrolock when a driver goes through deep water, there are many ways to accidentally introduce moisture into the engine and hydrolock it. The amount of damage that occurs to the engine depends on the situation.

For example, if your engine hydrolocks while idling or parked, you’ll probably just need a tow and have the water drained from the engine.

Your engine can also hydrolock when it’s not running. This happens when liquid fills the cylinders and prevents the starter from cranking the engine. This is the best-case scenario for a hydrolocked engine because the only risk of damage is if you leave the liquid in your engine.

However, it can be extremely dangerous if your engine hydrolocks while driving. Bent connecting rods, cracked crankshafts, fractured cylinders, blown oil seals, and even a destroyed engine block can result from a hydrolock at the wrong time.

A hydrolock can happen in a variety of ways, including:

  • Driving through deep water
  • A coolant or oil leak
  • Water entering the intake
  • Fuel injector leak

Cold air intake engines are more susceptible to hydrolocking, but any engine can experience it in the right conditions.

How do you know if your engine is hydrolocked?

Your car will display different symptoms depending on the operational status of your engine at the time of the hydrolocking, including: 

  • Unexpected sputtering
  • Sudden stalling
  • The engine refusing to turn over
  • A thump noise when you try to start your car
  • A hammering or knocking noise

Before the hydrolock is set, you’ll notice that your car will start running rougher than usual. If only a small amount of water seeps into your engine, it might escape through your exhaust. However, if more water enters the engine, you’ll hear a loud knocking.

When too much water enters the engine, it might run for a few more seconds. Then, with a loud thud, your engine will shut off.

At this point, your engine won’t turn over without repair. You’ll need to have your vehicle towed to a mechanic shop to flush the engine.

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Is a hydrolocked engine covered by insurance?

Is hydrolock covered by insurance? Yes, if  you have the misfortune of your engine hydrolocking, your car insurance will cover it, but only if you have the right policy.

Liability and collision insurance won’t cover water damage, but comprehensive does. Comprehensive insurance covers damage caused outside of accidents, including bad weather, vandalism, theft, fire, and flooding.

However, even comprehensive might not cover a hydrolocked engine. If the damage to your engine was caused by poor maintenance or intentional driving (such as purposefully driving into deep puddles), your insurance company could deny the claim.

How much does comprehensive auto insurance cost?

Comprehensive coverage is generally affordable for anyone interested in protecting their car from hydrolocking and other unforeseeable damage.

The actual amount you’ll pay depends on a variety of factors, including the car you drive, your age and gender, and even your credit score. However, you can get an idea of what you’ll pay by checking the average annual price of comprehensive and full coverage auto insurance in your state.

Average Annual Comprehensive Auto Insurance Coverage Rates by State
StatesAverage Annual
Comprehensive Rates
Full coverage
New Hampshire$115$859
New Jersey$130$1,457
New Mexico$197$1,043
New York$176$1,484
North Carolina$129$824
North Dakota$246$817
Rhode Island$138$1,450
South Carolina$197$1,132
South Dakota$305$860
West Virginia$215$1,072
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Comprehensive insurance tends to be very affordable, but you typically can’t buy comprehensive car insurance alone. Most states require liability coverage before you can legally drive, and several also require uninsured motorist coverage.

Comprehensive insurance will increase the cost of your policy, but it will be well worth the price if something happens to your engine.

How do you file a hydrolocked engine insurance claim?

A hydrolocked engine insurance claim works the same as any other claim if you have comprehensive insurance. You’ll first need to contact your insurance company. Many big insurance companies have mobile apps or websites you can use, but you can always call your agent.

Once the claim process is started, the company will send an adjuster to look at your engine. The adjuster will try to determine the cause of the hydrolock and whether the damage was intentional.

If the claim adjuster signs off that your policy covers the damage, your company will double-check that you signed up for your policy before the damage occurred. If you try to make a claim for damage that happened before you bought your coverage, you might be accused of committing insurance fraud.

As long as everything is correct, the claims process will move forward. After you pay your deductible, the company will cover the rest of the repairs.

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Can you repair a hydrolocked engine?

Usually, hydrolocked engines can be repaired, though the cost will depend on how much damage was done.

How much does it cost to repair an engine after a hydrolock? Unfortunately, repairs can be very expensive. Typically, you’ll be looking at a bill between $3,000 and $8,000.

The first step to repairing a hydrolocked engine is to get all the water out of it. Then, a mechanic will replace the spark plugs and crank the engine. Sometimes, that’s all that you’ll need to get your engine back into working order.

However, there can be a lot of unseen damage to your engine after it hydrolocks. If you were driving the car when it happened, you’d likely have severe engine damage. A mechanic will probably need to pull out the internal combustion engine, strip it down, and inspect every part for damage.

The most common damage includes scored bearings, cracked pistons, and bent connecting rods. Additionally, the cylinder head will need a pressure test, and the engine block should be checked for cracks. Finally, the crankshaft should be measured to make sure it’s straight.

How to Find Affordable Auto Insurance to Cover Hydrolock

Water can enter your engine in a variety of ways, some of which can be avoided and others cannot. Comprehensive coverage can help protect your engine from the extreme damage that can come from a hydrolock.

Comprehensive auto insurance rates will be more expensive, but it can cost you up to $8,000 or more to fix a hydrolocked engine without coverage.

Now that you know a hydrolocked engine is covered by insurance, the next step in protecting your car is to shop around for quotes. You can find the perfect insurance policy for your needs by comparing rates with as many companies as possible.

In the meantime, please feel free to type your ZIP code into our helpful tool below to find reasonable rates in your area for the comprehensive coverage that will help you with your hydrolocked automobile.

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