Smoke Coming from Radiator? Try These Fixes

Smoke Coming from Radiator

When driving your car, smoke may start coming from under its hood. At the same time, your car’s temperature warning lights may start glowing, telling you there’s a severe problem. You should stop your car on the roadside to troubleshoot and find an urgent fix to the problem before proceeding with your journey. Driving an overheated car may cause even more problems. Sometimes you may have no alternative than to have your car towed. Read on to learn more about how to fix a leaking radiator.

How a Car Engine Works

The engine is an essential component that moves your car. This vital part of the vehicle generates a lot of heat when running. It runs at exceedingly high power for an extended period courtesy of a complete system that keeps pressure and heat under control, including its cooling system. Car radiators play a crucial role in keeping the engine cool. Therefore, your cooling system must be working correctly to enjoy a seamless drive.

You cannot talk about your car’s cooling system without mentioning the radiator. This vital component has a coolant which absorbs heat from the engine and carries it out of the engine, thereby enabling the engine to run smoothly without overheating. The radiators are strategically placed at the front of the engine, thereby enabling them to get a flow of air, which is crucial in the system’s effective operation. Besides, a cooling fan enables the radiator to pull cool air, thereby boosting the fluid’s cooling ability. Consequently, engine overheating is avoided.

Overheating can cause a lot of damage to your vehicle. For instance, when the cooling system is not working, the car may damage the engine, radiator, and other essential components. Cooling the engine may not be enough to rectify some of these damages. However, regular maintenance of the car’s cooling system can reduce the frequency of these faults and enhance the car’s performance.

When your car engine overheats, you should begin by opening the windows and turning on the heaters. At this stage, the gauges should also be telling you that there’s overheating. Then, look for a safe place, park your car, and turn off to stop further damage. Let the engine cool off before checking it thoroughly. It is essential to learn how to fix a leaking radiator even when you don’t know a tad bit about cars, to avoid such inconveniences.

Main Causes of Radiator Leaks

Unlike some other car damages, radiator malfunctions are easy to notice. Whenever you see steam billowing from under the engine, something is most likely wrong with the radiator. Since radiator damage leads to overheating, it’s always advisable to act quickly when you observe this problem. Here are some of the main problems that may cause radiator leaks.

Important: If you want to save $100s in servicing, diagnosis, and repair costs, improve your car's performance significantly and increase its value by 1.2x with little effort, download our Beginners Auto Maintenence & Repair Manual now. 

Damaged Water Pump

You may see smoke coming from the radiator when you have a damaged water pump. The water-pump functions by moving the fluid around the engine and back to the radiator. However, after some time, the pulley and bearings may become weak, adversely affecting the water flow rate. This may cause the engine to overheat and the smoke to come from the radiator. Other factors that may lead to the water pump’s damage include broken impeller blades and broken timing belt. You can tell if you have a damaged water pump when the shaft seal leaks or when the blades wear down.

Faulty Thermostat

A thermostat (view on Amazon) is mainly tasked with regulating the flow of coolant going into the radiator. The engine may overheat when this important device is faulty, as the fluid may not have the right temperature to regulate engine temperature. The thermostat may also malfunction when it is stuck in the closed position.

Reduced Coolant Level

The engine cools off when the coolant circulates inside it. Smoke may start exiting from the radiator when the level of the liquid drops. Coolant leak or long-term neglect may cause this drop. Your engine may begin to overheat when you don’t have enough coolant. Your mechanic may help you to identify if there are other causes other than low coolant levels.

Presence of Air in the Cooling System

A cooling system operates in such a way that the air does not get inside. However, the air may get inside when flushing the radiator. This air may create pockets that interfere with the flow of the liquid, thereby causing overheating.

Faulty Radiator Cap

The radiator cap helps in maintaining pressure in the cooling system. Among other things, the radiator cap allows the coolant to return to the radiator after the car has cooled down. However, the radiator cap may go bad and be unable to function properly. You can tell a bad radiator cap when the engine overheats; the hose collapses, the reservoir overflows, the air gets inside the cooling system, or when the coolant leaks. Therefore, a damaged radiator cap can cause a radiator leak.

Leaking Hoses

The hoses involved in the circulation of coolant/antifreeze to and from the radiator can make smoke come from the radiator. Hoses are mainly made of rubber. After collecting sediment over a long time, the hoses may rust and become leaky. Wear and tear can also cause cracks, thereby making the hoses leaky.

Faulty Radiator

A hole in the car radiator may also cause radiator leaks. The crack or hole maybe because of wear and tear. Besides, a bad jolt in the road may also damage the radiator causing the smoke to come out. You can tell a damaged car radiator through coolant leaks, low coolant levels, rising temperatures, and white smoke.

Damaged Radiator Fan

A small amount of steam may begin coming from your bonnet when your radiator fan fails. This is especially common with most of the new cars with electric fans. The fans only work at low speeds, and when they fail, the engine may overheat until the car drives at high speed.

Dirty Radiator

Your car radiator may start to emit smoke if it is dirty. Rust and sediments may accumulate in the radiator over a long period, adversely affecting how it functions. Debris may also be stuck, thereby interfering with the flow of the coolant. A bad or clogged radiator may cause fluid discoloration, damaged fins, or coolant leaks, among other issues.

Main Reason Why Smoke is Coming Out Of Your Radiator!

If your radiator fan is bad, chances are that you’re failing to maintain your vehicle. When you don’t look after certain components, this can cause a knockon effect and damage parts like the radiator fan. If you want to avoid this problem from happening again, you’ll need to look after your car.

If you want to avoid radiator problems or other issues and save $100s of dollars that you’ll spend at the auto repair shop, you’ll need to service your vehicle often – you can use our mechanic-rated Auto Maintenance and Repair Manual to do this. It’s basically what mechanics use to go through your vehicle to check if there are any problems that need fixing. As soon as they notice the most minor problem, they’ll ask you to fork out some money even though it’s a problem you can fix yourself in minutes – the manual will teach you how to maintain your vehicle every few thousand miles and it’ll teach you how to fix minor problems that mechanics will ask you to pay for; saving you money in the long run.

A lot of our readers have the Auto Maintenance and Repair Manual printed on their garage wall and 92% of them haven’t visited the auto repair shop in the last year because they know what to do to avoid problems. All it takes is giving your vehicle a little attention every few thousand miles and you’ll never spend money at the workshop again.

How to Fix Radiator Leaks

Given that a car radiator plays a crucial role in preventing a car engine from overheating, it’s important to learn how to fix it. However, given that a myriad of factors may cause radiator leaks, there’s no single solution to this problem. However, some of the ways in which you can solve this problem are discussed below.

Your water pump should be in good shape all the time as it circulates water between the radiator and your car engine for temperature regulation. When you observe the coolant/antifreeze leaking from the water pump, there’s something wrong with the water pump. Screeching noise from the radiator is another indicator. You should repair the water pump after cooling the car engine. If the problem is the timing belt, you can replace it. Remove the fun assembly and the water pump and locate the damaged parts. A leaking water pump will cause the cooling system to lose coolant leading to overheating.

You can fix radiator leaks by replacing a damaged thermostat. You can tell a faulty thermostat when you observe coolant/antifreeze leaks around it or overheating warning on the dashboard. Your owner manual should help you to locate it. You should only replace the thermostat when the car is cool since you have to drain the coolant.

Inspect the level of your coolant regularly to ensure that it does not go below the recommended levels. Identify the cause of this drop and fix it. Radiator and radiator hoses leaks are among the main causes of this reduction. If you find yourself refilling the coolant regularly, then there’s a leak. You should add the coolant whenever the level drops. However, refilling should only be done after the engine has cooled.

During the flushing process, it is important to ensure that air doesn’t get inside the cooling system. Allow the engine to cool before flushing the cooling engine. You should follow your manufacturer’s instructions. Fill the reservoir with new coolant and run the car for a few minutes to ensure there’re no air pockets. During this process, turn the interior heater to the maximum.

Check the radiator cap regularly to ensure it is functioning properly. You can tell a faulty radiator cap if the coolant overheats. Other indicators include leaking coolant and the collapse of the radiator hose, among others. You should not remove the radiator cap until the engine is cool as the hot coolant may shootout causing serious injuries. In most cases, a radiator cap should be replaced after five years.

Check the hoses regularly to address any damages. You can only maintain the performance of your cooling system by regularly changing the hoses. You get new hoses when the old ones are swollen or cracked at the ends. Remember to drain your coolant during the replacement. You should also flush the system before adding new coolant after replacing the faulty hose. Sometimes your mechanic may advise you to change the hoses after a certain interval for good performance.

It’s always important to confirm that your cooling system is in good shape. Check your radiator regularly to ensure that it not damaged. Whenever you observe any issue, refer to your vehicle repair manual. Your car computer can be a powerful tool when troubleshooting. Make sure you understand the test that you need to conduct.

You should fix a faulty radiator fan if you drive a new car with an electric fan. You can tell if the fan is the problem if the overheating stops when you get on a faster road. Allow your engine to cool before fixing the radiator. Check for grease, tar, or other substances that may have blocked the fan or blades and remove them. You should have a degreaser and pipe cleaners when cleaning the fan.

You should flush the system when replacing your old radiator fluid. Doing so will help in eliminating rust and particles that may accumulate, making the radiators leak. Improperly mixed antifreeze is responsible for most corrosion in the cooling system. Ensure you catch the coolant in a drain pan and take it to the nearest coolant recycling plant, as it is illegal to dispose of it in the drainage system in most municipals.

Many factors may cause smoke to come from the radiator. Whenever you observe this, it’s always advisable to stop your engine to avoid more damages that may be caused by overheating. Sometimes you may be unable to tell the actual cause of overheating. Therefore, it’s advisable to always contact your mechanic to ensure that a professional inspect your car. You should also have the entire cooling system screened after a couple of years to prevent any problems. Always refer to your manufacturer’s manual for more information.

Job Guthiri is a freelance writer with 3 years of experience writing for Motorsrun and other established automobile outlets. His focus and key interests are Tacomas and maintenance. Read our Editorial Guidlines and Fact Checking process.