Should You Drive a Car With a Cracked Radiator?

Driving a car with a damaged radiator not only damages the engine but also poses danger to your life and your loved ones. So the answer to this question is absolutely no. Well, although your car can still run, it is highly recommended to get it repaired for safety purposes. A cracked radiator may cause your engine to overheat, break down or catch fire.

When your car overheats, the piston snaps and may cause serious engine damages such as;

  • Damage to rotating parts due to increased heat and vibration in the engine
  • Carbon formation beneath the piston walls
  • Lubrication failure due to cylinder wall deformation

The Actual Functions of the Radiator 

A radiator is a large and rectangular structure with gill-like features that can either be metallic or plastic and is located under the hood of a car. The coolant present in the radiator is passed through the engine block and absorbs the heat created by burning fuel. Once the coolant absorbs the heat, it is passed through the radiator where it is cooled.

Actual Functions of the Radiator

How to Tell that Your Car Radiator is Cracked?

There are telltale signs of a faulty radiator and these mostly apply if one or several of the channels have a leaky dent or there’s damage that is growing progressively. You would begin to see;

How to Tell that Your Car Radiator is Cracked

Coolant Leaks

the coolant is a green or red fluid. Once you see a puddle of this fluid under your car, just know that your radiator is cracked.

Overheating of the Engine 

the radiator works to cool the engine. If your engine overheats yet everything is in good shape, then your radiator may have a crack. When this happens while driving, pull over so as to avoid damaging your engine further.

The Need for Frequent Coolant Refill 

although the coolant should be refilled regularly if you notice that your vehicle requires a constant refill, chances are that your radiator may be cracked. 

What Causes the Radiator to Crack?

Now that you have gathered on how to tell that your radiator is cracked, it is equally important that you understand the reason behind it. Your radiator may crack because of;

What Causes the Radiator to Crack

A faulty thermostat

the thermostat monitors the engine’s temperature and determines whether the coolant and water should be released or not. If the thermostat is faulty, it allows too much coolant into the radiator which causes excess pressure on the radiator thus it cracks.

A faulty or leaky gasket

when the gasket of your car is faulty, it affects the radiator in a number of ways such as causing overheating which could result in cracking. It also allows exhaust gases into the coolant of the radiator.

Hot weather

very hot weather affects the radiator’s cooling function. The radiator during such weather conditions is forced to work extra hard to cool the coolant. If the coolant content is low, the radiator strains to the point of cracking.

Cold weather

in cold weather, the radiator fluid may freeze and expand causing cracks to appear.


this is most common in coastal areas where humidity is high. If the radiator is exposed to such conditions, it may rust and break.

How to Fix a Cracked Radiator

Since driving around with a broken radiator is not an option, let’s look into the repair and the cost it involves. A cracked radiator repair cost could be quite expensive depending on where you get it done, the model of your car, the cost of parts, labor costs, and some miscellaneous charges (such as hazardous waste disposal) that may arise.

Fixing the radiator also depends on the material of the radiator. In this sense, it is more expensive to fix a metallic radiator than the plastic radiator.

Metallic radiators

To fix a cracked radiator on metallic radiators, welding of the leak will be required. The crack needs welding using a gas torch or a propane torch. If the leak is too large, whether you know how to fix a cracked radiator or not, welding will not work, the replacement will be required.

Plastic radiators

A cracked radiator fix for plastic radiators is much cheaper than the metallic ones. This is the case because you can spray an adhesive to seal the leak. This adhesive contains a mixture of two parts of epoxy and JB weld material.

Alternatively, you can also opt to purchase a ready-made kit from auto stores and use it to repair your radiator. However, if the damage is extensive, you will have to replace it.

Steps to fix a cracked radiator plastic

If you want to save some bucks for your repair cost, then you have to know how to fix a cracked radiator plastic yourself. This is the case because, with this knowledge, you get to avoid labor costs that a mechanic will charge you if he repairs it for you.

Steps to fix a cracked radiator plastic

Purchase a ready-made kit that is designed specifically for fixing cracks from your local auto store. It comes with directions, so follow it to the letter. Your kit may entail the following; sandpaper, fiberglass cloth, two-part epoxy and a metal tube brush. Before you begin to fix, ensure that the radiator is cool, empty, and grease-free.

  • Prep the area that you plan on fixing. Clean the dirt and grease with a rag
  • Sand the surface using the sandpaper to remove any remnant
  • Using a drill, drill holes at the end of each crack to prevent it from breaking further
  • Sand the drilled area to keep the surface smooth for attaching the fiberglass cloth
  • Cut the fiberglass cloth with scissors to a shape in line with the crack of your radiator
  • Mix the epoxy, spread the fiberglass over the cracked area and smear the epoxy on to the fiberglass cloth and the exterior of the cracks as quickly as you can before it hardens
  • Leave it to dry

If there are no leaks after the repair, then your work here is done but in the event that leaks still occur, you will have no other option but to seek professional services. You may also be required to replace the cracked radiator if the efforts to repair it failed. This might cost you an extra dime but then you will have settled the issue.

However, if you managed to fix the issue, remember to place back the radiator with all its mountings and nuts intact, to minimize possible vibrations that might again damage it. Another good maintenance tip is, ensure to check the level of coolant inside your radiator every morning before leaving with your car.  

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