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Hydrostatic Lock Cover in Car Insurance: Do you Need One?

Team AckoJan 17, 2024

India has witnessed some of the most ferocious natural calamities over the years. People suffered hugely during this time. Loss of life had the most devastating effect but damage to property and vehicles was also prominent. To financially shield yourself from damages not covered by Comprehensive insurance, you can buy extra insurance coverage. In this article, we will discuss that extra coverage, specifically a hydrostatic lock cover in car insurance.




What does hydrostatic lock mean?

One of the many effects of heavy rains or flooding is that water can seep into a car and cause damage. This happens because a car is not designed to accommodate water in its parts, especially the engine. It can work seamlessly only when running on a particular type of fuel, i.e. petrol, or diesel. 

Water is a highly powerful substance when it comes to compression. It does not budge even to a heavy force. On the other hand, the combustion chamber of an engine is designed to compress a much lighter substance — air. When an engine is filled with water, it tries to compress the liquid but ends up getting damaged in the process. This damage is called hydrostatic or hydraulic lock. This was the hydrostatic lock definition.

How does a hydrostatic lock occur?

A hydrostatic lock in car occurs when it is driven after the engine is filled with water. There can be many different ways for this to happen. The two most common causes are natural calamities, and driving the car through a waterlogged area, say a ditch or a stream.

During natural calamities like heavy rains or floods, the water can enter a parked car. It not only damages the interior i.e. the cabin area, but also the mechanical and electrical parts of the car. Water ingression has the most effect on the engine and other electrical components of the car.

It is important to note that a hydrostatic lock will only occur if the engine is running. It does not damage the engine as such if the water has entered but the engine is not working. Here, you still have to depend on a professional to take a look at the engine and get the water removed. However, if water enters the engine and it is in motion, then the pistons will try to compress the water instead of air and the opposing force is so heavy that they can bend and damage.

Remember that you must not try to start a car without professional guidance especially if the car has passed through a waterlogged area or has suffered visible damage from a natural calamity. Chances are that water is still present in the engine and must be removed manually.

Is there a need to purchase a hydrostatic lock cover in car insurance?

A hydrostatic lock cover, meaning in car insurance, is to get coverage for the car’s engine against costs related to repairs or replacement in case of a hydrostatic lock. To understand if you are covered against the hydrostatic lock, you must take a look at the car insurance policy to find the type of plan you have.

Basically, there are two kinds of car insurance plans — Third-party Car Insurance and Comprehensive Car Insurance. You can get a hydrostatic lock cover only if you have a Comprehensive Car Insurance policy. This is because the former type of plan does not cover your car with insurance.  

In case you have a Comprehensive Plan, you can choose to buy the Engine Protect add-on where you will get coverage for the hydrostatic lock. While a basic Comprehensive Policy covers the car against different types of damages, it does not cover the expenses related to the engine damage. So, buying the add-on is necessary if you are looking for extensive coverage.  

How to get insurance for a car's engine?

Here are the steps for buying a car insurance policy with coverage for the hydrostatic lock.

Step 1: Download ACKO’s mobile app or visit from a computer.

Step 2: Enter your car’s registration number and answer a few questions that will help you get the most suitable coverage.

Step 3: Choose a plan from the list and select the Engine Protect add-on. Proceed to make payment.

If there are no time gaps between the last and the current policy, we may not ask for an inspection. You can thus get the new policy with the Engine Protect add-on within a few minutes. Check the inbox of your registered email address for the policy document


The very first instinct after a car breakdown is to try and start the engine. We don’t think much and are desperate to turn the key (or push the start button). But is counterproductive in the case of a hydrostatic lock.

The connecting rods of the piston can bend under the tremendous pressure from the piston trying to compress water. Even the piston rings can break. All this will lead to a high repair bill. Thus, avoid starting a car when it stops working after being in the water for a long time.

In an unfortunate case of the hydrostatic lock, ensure that you have a Comprehensive Car Insurance policy with the Engine Protect add-on so that your plan covers such expenses. Buying and renewing the policy in time is equally important.

Frequently asked questions

Here is a list of common questions related to car insurance and hydrostatic lock.


If my car’s engine has a hydrostatic lock, can I use it?

It is not advisable to use the car once you realise that a hydrostatic lock might have kicked in. This usually happens when you drive through a knee-deep or a higher level of water. The engine stalls when water enters the chambers. If you try to start the car with water in its engine it can cause severe damage. Thus, it is advised that you must not try to use the car if there is water ingression.

Do electric vehicles also have a chance of suffering a hydrostatic lock?

The mechanisms required for a hydrostatic lock to occur are not present in an electric vehicle. It runs on a high-capacity battery and electric motor, and not with the help of a combustion engine.

Is it possible to repair the engine after a hydrostatic lock?

Yes, a professional mechanic can help you with the repair work if your car suffers a hydrostatic lock. Some car owners prefer to do the process themselves, but one must be highly knowledgeable to repair a hydrostatic car lock.

Is hydrostatic lock claim allowed under car insurance?

If you have a basic Comprehensive Policy with no car insurance add-ons then you may not be allowed to make a claim for the hydrostatic lock. However, if you have the Engine Protection add-on then you can claim for the related expense. Be sure to contact your car insurance company before making a claim. 

You can also consider buying the Zero depreciation car insurance plan to get the maximum claim amount.

Are all engine components damaged because of a hydrostatic lock?

Usually, all the components are not damaged if a hydrostatic lock sets in. It only affects the piston,  cylinder wall, and the connecting rod of an engine. However, the extent of damage depends on the size of the engine and the amount of water present inside it.

Disclaimer: The content on this page is generic and shared only for informational and explanatory purposes. It is based on industry experience and several secondary sources on the internet; and is subject to changes. Please go through the applicable policy wordings for updated ACKO-centric content and before making any insurance-related decisions.


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