Can One Drive With A Cracked Coolant Reservoir?

Can One Drive With A Cracked Coolant Reservoir?

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Can One Drive With A Cracked Coolant Reservoir?

A cracked coolant reservoir is a serious problem. Damaged coolant is a by-product of heat deformation, and it’s not pretty.

If you smell an unusual odor coming from your engine bay, it’s possible that your radiator cracked due to heat expansion.

This can result in major problems such as leaks and prolonged drivability issues in the extreme. Therefore, it’s essential to find and fix this issue quickly.

Can One Drive With A Cracked Coolant Reservoir?

Yes. The coolant reservoir is only a small part of your car’s engine, and you can repair it with a bit of DIY expertise. Removing and replacing your coolant reservoir might even save you some money.

All cars have the same basic composition — it’s just different distributions of metal pipes and plastic hoses in different places.

For repairs that require drilling into the metal or cutting through the plastic, protect yourself from injury by wearing eye protection before attempting anything inside your vehicle.

The reservoir is large enough to accommodate two quarts of coolant so that you may have got about two gallons of fluid inside the reservoir.

That’s a lot of coolants, and it can get pretty warm in there even under normal circumstances.

If you don’t have a cup to catch the broken pieces, they’ll likely fall into your car’s interior surfaces. This is never a good thing.

There are two connections on the reservoir’s side where the two pipes meet.

These give you access to fill your tank or bleed a low radiator fluid light, depending on what you need to do.

If you breakthrough one of those connections, that’s usually enough to cause a coolant leak.

You will not fix the reservoir because:

1. These reservoirs comprise brittle plastics prone to cracking.

2. Coolant is a toxic substance, so you don’t want it inside your home even if it’s not leaking.

3. It would be difficult to replace the piece because of plastic welds, which rarely work well with epoxy resin glues.

— You don’t want you burning your interior surfaces or inhaling dangerous fumes from a bad plastic repair job.

If you’re going to replace the reservoir, it’s better to get a new one that doesn’t need any work.

You should be able to find this part online or at your local parts store. If you can’t find one, try a new water pump instead.

What Happens If Your Coolant Reservoir Cracks?

Well, it depends on the type of engine you have. But the problem with a cracked or loose reservoir cap can lead to several other costly issues, such as a leak in the block and coolant circulation problems.

The cooling system in your car comprises several parts. First, you have the radiator. This is where the engine gets its cooling from.

The coolant travels throughout the small channels within the engine and into the water pump whenever it overheats.

The water pump pumps it to the reservoir, where it then goes to the engine block for circulation and back to the radiator again for re-cooling.

The reservoir is the storage tank for your coolant. This heat-resistant tank comprises plastic or aluminum. It holds the maximum amount of liquid that the car can need if there’s a leak somewhere.

For example, if you have a crack within the radiator, it will automatically send the coolant to the tank and fill it up so that your engine will still have an adequate supply of liquid to keep itself running smoothly.

The drainage tube is the long pipe that actively takes the coolant from the reservoir to the engine block.

It’s made of plastic or rubber and comes in various colors, including red, blue, pink, or orange, to match your vehicle’s design.

The downside here is that if you have water spots on your windows or windshield, it may look like there’s a leak, even though there isn’t one.

You can see how damage can happen to your cooling system in several ways. One of these is the intake manifold gasket leak.

This happens when the intake manifold gasket leaks coolant into the engine area. It may also get into the cylinder head and cause many problems.

Can One Drive With A Cracked Coolant Reservoir?

The intake manifold sits between your engine’s cylinders.

A leak in its gasket will allow coolant to enter your engine and even get into some of your car’s critical parts, such as the cylinders, combustion chambers, or valves.

The second way to damage your cooling system is by disturbing the coolant level within the reservoir.

Sadly, this can frequently happen to drivers who aren’t aware of how much liquid they’re putting into the reservoir.

What happens then is that when there’s too much liquid in the tank, it will flood into some of your car’s other parts, such as transaxle and suspension components.

You may notice that there’s a leak in some of these components.

How Does One Fix A Crack In A Coolant Reservoir?

There are various potential solutions for this problem depending on the cause of the crack and the materials available at hand.

If the crack is on the reservoir’s surface, try to mix some porcelain paint with coolant (or use any other color that matches your car) in a ratio of 1:1 and apply it to the surface crack.

If the crack is near a coolant hose, then you will need something to seal it off from the air. If you have any grease or petroleum jelly around, this would be perfect for this purpose.

If no grease is around, try to buy some petroleum jelly at a hardware store.

This should help seal off the crack and prevent air from escaping. Ensure that you do not put any petroleum jelly into the reservoir as it may cause unexpected leakages.

If your reservoir is steel-made, you can try to weld it back together. At first, place a piece of sandpaper to rough up the crack, making it easier for the welding material to bond into it.

Then start using a welding torch to weld the steel together. Make sure that you are using the correct welding material for this purpose.

Use caution when working with hot materials. Do not burn yourself.

Ensure you clean off the hand marks and clean up any spilled liquids before attempting to use your car again.

What Can A Bad Coolant Reservoir Cause?

Acid contamination causes a bad coolant reservoir. If any acid gets into the reservoir, it will corrode its metal.

This will cause a pressure build-up in your engine and leak through small cracks in the tank or down through your radiator.

This can lead to a lot of expensive damage that you may have prevented by replacing your coolant reservoir with one made from materials that are not as susceptible to corrosion.

You’re better off replacing it early before you experience this issue. However, you can also check for a faulty heating system.

When your car is at operating temperature, check the coolant reservoir. If it has a boiling action or steam coming from it, there’s a problem with your heating system.

This is often because of a malfunctioning fan switch or a leak from a cylinder head gasket. You should have this checked out by an auto repair shop to prevent overheating and further damage to the engine.

The only other possibility is that a coolant reservoir can become clogged because of small particles of dirt or debris getting trapped in its bottom.

Overheating, improper drainage or excessively dirty coolant can cause this. Check your coolant every month and replace it when necessary to prevent this.

You’ll also want to make sure you properly drain your system.

Can A Car Run Without A Coolant Reservoir?

Yes. A car can run without a coolant reservoir. You must have a very efficient radiator, and you also have to keep it topped up with water.

It will take more time before the engine overheats, but monitor the temperature gauge and refill as needed.

Of course, you are only carrying out a few mechanical things when performing this procedure.

By stopping the waste oil return pipe and the coolant to return passage and by removing the coolant reservoir, there is a risk that any accumulated water will expand.

Thus, the coolant reservoir has a pressure relief valve that releases excess pressure. This relieves much of the strain on the cooling system.

So, if you want to remove the coolant reservoir on your vehicle, here is how to do it:

1) Shut off all electrical systems and remove the battery if it is there (it does not have to be).

2) Turn off the ignition.

3) Remove the air filter and fire extinguisher and disconnect from the battery any electrical connectors (wiring harnesses, etc.).

As long as you remove these connectors, make sure that you have still totally shut down the engine. There is always a risk of electrocution.

Some cars with a CAN-BUS system are not doing enough to remove the battery; you also have to switch off unnecessary electrical systems to shut down the vehicle completely.

4) Close the engine compartment hood.

5) Start draining of coolant from the radiator:

• Open the cylinder head cap and drain off coolant from each cylinder head into a bottle. Let it cool down before opening any other component.

If a bottle is not available, open the drain valve on the radiator and drain it into a bucket.

• Access the coolant reservoir and drain it completely. How you do this will depend on the model of the vehicle.

Some models have this in front of the engine and others in the rear, so make sure you search online on how to do it on your specific vehicle model.

You then want to disconnect any wiring harnesses attached to this unit because you will probably have to remove some more components later on.

6) Keep the coolant reservoir connected to the radiator. This will ensure any water in the reservoir does not mix with the new coolant that you are about to fill.

Why Is My Coolant Reservoir Dirty?

Your coolant reservoir is dirty because it contains antifreeze liquid. Antifreeze is a chemical that prevents heat-induced corrosion on metal surfaces due to temperature differences between the engine and coolant reservoir.

Depending on which model you own, you need to replace it every three years, or 12,000 miles.

Also, make sure you charge your battery and, when it’s low, put it on a charger for at least 10 hours before replacing the coolant reservoir.

Coolant Reservoir Replacement Steps:

1. Open the bonnet, then remove the air intake ducts from both sides of the air intake box.

This ensures you don’t burn yourself with hot steam when you disconnect and remove the coolant reservoir.

2. Notice the cap is on the right side of the coolant reservoir. Disconnect the electrical connection to ensure you don’t spill coolant everywhere when you disconnect it.

3. Undo the clamp that holds the reservoir to its bracket, then remove it from the car.

It’s easier to set it down somewhere that is easy for you to find later, like on a cardboard box or something like that, but be careful, so you don’t drop or spill it.

4. Take the replacement reservoir, place it inside the bracket, and fasten it with the clamp.

5. Reconnect the electrical connection and refill your coolant reservoir with the new coolant.

6. Make sure you check all your hoses, belts, and fluids so that your engine will run at full power for you.

When removing the reservoir, don’t spill any of the antifreeze on yourself or any other surface that may rust by coming in contact (your paint is a prime example).

Also, note the reservoir gets very hot, especially in the summer. Ensure your hands are dry, and you don’t burn yourself.

Why Is My Car Leaking Coolant But Not Overheating?

Your car is leaking coolant but not overheating because the radiator is not overloading because of lack of an engine coolant.

Your car’s cooling system comprises the radiator, the thermostat, and the heater. If one or two of these three components is faulty or damaged, your car will leak coolant and not overheat.

A radiator has a fan that circulates air through metal fins to keep engine temperatures down. You connect a thermostat to the engine and radiator.

The thermostat maintains coolant flow through the radiator by opening and closing.

A heater core sends hot coolant to a heater, allowing you to warm up your car while it’s stopped.

If your car is leaking coolant but not overheating, you may have a faulty fan or a damaged radiator. The fan blows air through the fins of the radiator.

If there are any obstructions in its path, the fan can’t work correctly. Thus, you need to check your car’s air filter to ensure that it hasn’t become blocked by a large quantity of dust or dirt.

A damaged radiator can also impair a fan’s circulate air through the engine and radiator. If a fan isn’t working efficiently, your car will take longer to warm up, and the engine will overheat.

Another probable reason your car is leaking coolant but not overheating is a faulty thermostat.

It’s essential to have your thermostat checked out by a mechanic if you suspect it’s faulty.

A faulty thermostat can prevent the flow of engine coolant through the radiator and heater core, causing your car to leak coolant without overheating.

A good mechanic can tell you whether you need to replace your thermostat. You know the radiator or heater core problem if your car is overheating.

Abrasion from a rock hitting it or rusting can damage a radiator. A damaged radiator will leak coolant and overheat.

Is The Coolant Reservoir Supposed To Be Hot?

Yes. If a car’s coolant reservoir is cold, the engine won’t work. If it’s hot, the engine will have better power and efficiency.

If you see that your car’s coolant reservoir isn’t hot when you start your car, there could be problems with your heating system in the winter months.

You can also use a thermometer to monitor your engine’s temperature to know when to keep it on or take it off during summer.

Coolant reservoirs are in the engine’s front. The current system has coolant reservoirs because car engines need to stay hot.

If you leave your car untouched when it’s cold, it will not turn on.

Engines have to be hot for them to work well, and because of this, you will find coolant reservoirs placed in the engine’s front during manufacturing.

Coolant reservoirs aren’t that big. They’re designed to hold coolant fluid. It’s supposed to be hot because the engine has to be hot to work correctly.

If your coolant reservoir is cold, there could be problems with your car’s engine.

There are coolant reservoirs on some engines on both sides of the compartment to know whether both sides are doing well. Usually, one side should be as hot as the other.

Some people might say that coolant reservoirs aren’t supposed to be hot, and they’re right. They’re supposed to be cold, but coolant reservoirs should be hot in a regular engine.

This is because cars work better when they’re hot. There’s no particular temperature that a coolant reservoir should have. It just has to be hot enough for the engine to work well.

What Does Brown Sludge In Coolant Mean?

Brown sludge in the coolant is a fairly common mechanical problem that can sometimes cause an engine to overheat.

It usually happens when air bubbles enter the cooling system and mix with coolant, making the fluid brown or coffee-colored.

Many manufacturers recommend a low coolant level test after an engine has been running or idling for several hours.

This is because air bubbles are more likely to collect in the coolant after an engine has run; they stay put until the engine has cooled and then rise to the top of the coolant.

The brown sludge may not be harmful, but it certainly won’t do any good either.

If you’re seeing brown sludge in coolant, your next step should be to have the system and cooling fan replaced before you get stranded on the side of a busy road.

Brown sludge in the coolant is one of those annoying but minor problems that can turn into something much worse if left unattended.

Air bubbles in the coolant can cause a lot more damage than, say, a loose water hose connection or leaving the windshield washer fluid cap off.

Why Is My Coolant Reservoir Black?

Your coolant reservoir is black because it is old, meaning it’s no longer very effective in making sure your car’s engine is not overheating.

It has become so diluted that it will not do much for the engine.

If you are experiencing a lot of heat coming from the exhaust and the side of your car, this could be a sign that you need to change your coolant reservoir.

Fixing this problem might also require other changes to address an issue with a leaking head gasket or sealer.

You might need to replace the head gasket or the coolant reservoir. A mechanic will be the best person to look at your car if you have overheating issues.

If you have a coolant reservoir leaking, you need to change the coolant.

Since this might be expensive, tell the mechanic before he starts and ask for his advice about what you should do about all this.

Some people ignore this issue because they think it will go away on its own, and it probably will if you keep the car warm and do not use it too much.

However, if ignored for too long, it will cause significant problems that could cost you many money to repair.

Can You Repair A Crack In The Coolant Reservoir?

Yes. If your coolant reservoir cracks and leaks coolant, you’ll need to buy an o-ring kit.

To repair the crack in the reservoir, start by removing the damaged reservoir cap and carefully prying away any plastic or gasket material that may block access to the crack.

Once it’s clear, insert one of the new o-rings into each end of the cracked area, working the o-ring into the groove by pressing it in one direction and then pulling back on it in the opposite direction.

So now you have a cut o-ring to fit the outer diameter of your coolant reservoir, with a length equal to the length of cracks in your reservoir.

When you’re done inserting the new o-rings, install the new cap on your coolant reservoir and hand tighten it — no tools needed. But don’t over-tighten it.

When your caps are too tight, they can cause damage to your reservoir, including cracking the o-rings and leaking.

Once the cap seats correctly, fill your cooling system with water and verify that it’s working correctly by performing a coolant pressure test using a coolant pressure gauge.

If there is no significant pressure loss when you add water, you’re ready.

What Causes A Coolant Reservoir To Crack?

The most common causes of coolant reservoir cracks are the old age and cooling cycles. The most frequent occurrence is in late autumn or early spring when new vehicles experience their first deep freeze.

The second most common cause of a cracked reservoir is abuse caused by overzealous.

Owners who wash their car under the faucet or apply pressure to get rid of dirt and grime that is hard to reach with a cloth, a towel, or even a hose.

This can cause a crack in the reservoir as well.

Another common cause of a cracked coolant reservoir is the thermal expansion and contraction during temperature changes, although this is not as frequent as the other causes mentioned.

The reservoir’s design handles these temperature changes without breaking.

Coolant reservoirs come from soft plastic with what seems to be a very thin wall. Despite their thin walls, they handle temperature changes and rough treatment without cracking.

A coolant reservoir comes from what seems to be a very thin plastic, but it’s not as fragile as it may seem.

Although thin and easy to break, the reservoir can handle temperature changes and rough treatment without cracking if appropriately designed.

This is an excellent indication of quality craftsmanship in manufacturing if you think about it.

Should The Coolant Reservoir Have Pressure?

Yes. That’s why you find the reservoir vented.

The pressure of the coolant inside helps to keep air from getting into the system by pushing on the oil film in the cap and keeping it tight against the opening of your radiator.

The vents are also responsible for giving you a good idea of where a leak may come from because they release air bubbles you can see when they’re escaping.

Your ear and nose are your best leak detector. If you can smell a coolant leak, it’s probably coming from someplace near the engine.

Oil alone will not help with a coolant leak, it can’t get out of the system as fast as the coolant does. Some oil and antifreeze mix in a coolant mixture, but not enough to stop the leakage.

For this reason, the best thing you can do is get a can of “coolant stop leak” and run it through the system.

This will add 2 or 3 ounces of oil to every quart of antifreeze you put in.

You should use the antifreeze because the stop leak will degrade it, but don’t worry; as long as you get a good flush out when attempting to fix the leak, there shouldn’t be any problem.

If the car is under warranty, you should NOT run a stop leak in the system before taking it to the dealership. You are just asking for a hassle, and it might be enough to void your warranty.

When I Turn My Car Off, I Hear Bubbling?

Your car makes a bubbling sound when you turn it off because the engine is still hot. The liquid coolant boils within the radiator and cools the engine.

Turning off your car doesn’t cause any damage to your vehicle or yourself. It’s the noise that bothers people.

You can make it away by switching off all of your lights, shutting down your electronics, setting out a towel at night to absorb some sounds, or purchasing a flat muffler for better performance and vibration.

The boiling sound occurs because of the metallic components in your radiator and your catalytic converter, which reduces poisonous gases.

The radiator changes the heat transferred to water and cools the engine when you turn off the engine.

The catalytic converter converts hydrocarbons into less harmful carbon dioxide and water vapor forms.

An oxygen sensor that checks oxygen levels in the exhaust system takes them out of the exhaust.

You can prevent the noise by turning off all your lights and electronics. Another way is to turn off your lights, do a U-turn around your neighborhood, and then come back into your driveway.

This releases the pressure from the radiator, and you don’t hear the boiling sound.

If you want to eliminate this noise, you can purchase a flat muffler that absorbs vibrations . To order a muffler, contact your local auto parts store.


Cracked coolant reservoir problems are few and far between and easily prevented.

If you look at the radiator from the underside of the vehicle, you will see a cap that allows you to add coolant to your system. That cap is called a cooling system reservoir.

It’s made from plastic with a rubber O-ring that seals your coolant system when it’s on top of your radiator and when it goes down into the engine.


Hi! I' am Tom. I faced many questions from customers about different products, and there was hardly any help on the internet. After learning all the things about these products as a manager the hard way, I decided to start a blog and help other people.

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