If you have a problem with the vehicle's cooling system, one of the causes could be the radiator. This element is designed to disperse the heat that the coolant absorbs as it circulates in the engine; however, a drop in fluid level caused by a leak or spoiled antifreeze could affect its performance. If your radiator isn't working well, there are a couple of things you can try before you need to hire a professional mechanic. However, remember that overheating the engine could lead to serious damage to internal components, and you should consider getting an expert if problems with the cooling system persist.
Steps
Part 1 of 3: Identifying a Radiator Problem
Step 1. Look for puddles of liquid under the vehicle
One sign that definitely confirms a failure in the cooling system is the presence of a puddle of coolant under the machine. Remember that there are several different fluids in the engine compartment that could leak, so check the residues carefully to see if they are oil, coolant or water coming out of the air conditioner.
- Touch the puddle with your finger, rubbing it on a sheet of white paper to observe the color of the liquid.
- If it's green or orange, it's probably coolant.
Step 2. Inspect the coolant reservoir
If you are concerned that the car is leaking this fluid, check the tank located in the engine compartment. Most of these vessels have notches on the walls to help tell if the liquid level is too low. Check the amount of antifreeze and, if it is low, top up with a mixture of water and coolant. After a few days, repeat the inspection looking for new variations in the levels.
- Remember to check the coolant levels with the engine compartment always at the same temperature (cold, after a break, or hot after driving).
- A reduction in coolant levels coupled with puddles under the vehicle most likely indicates a leak.
- If you are not sure where the antifreeze tank is, consult the car's owner's manual.
Step 3. Pay attention to changes in the thermometer on the dashboard
If the cooling system contains too little liquid or it needs to be replaced, it may have difficulty keeping the engine at optimum operating temperature. Keep an eye on the thermometer; if the needle continues to rise or sporadically indicates overheating, there is some malfunction in the radiator system.
- If the fluid fails to cool the engine adequately, it means that its level is too low.
- The coolant can eventually degrade as well. If there are no leaks but the engine overheats, a problem could be the now bad fluid.
- If you are not sure what the symbols on the gauges mean, consult the user manual to determine which thermometer is.
Step 4. Visually inspect the engine compartment
If you are concerned about a coolant leak, flush the engine with a garden hose to get rid of any debris that is already there. Start the car and check the engine, watching out for any coolant leaks. This liquid is usually under pressure, so the leak could be in the form of a splash or a drip; for this reason, you should wear safety glasses and be very careful when working under the hood with the engine running.
- Do not put your hands inside the engine compartment while the engine is running.
- Look for new signs of a coolant leak and then follow the path back until you find the hole or crack.
Part 2 of 3: Draining and Flushing the Radiator
Step 1. Wait until the engine is completely cold
The cooling system is under pressure when hot, and opening the radiator cap or drain valve under these conditions would cause severe burns. Leave the car parked for a few hours to make sure it is cold before touching any part of the cooling system.
- After a few hours, lightly touch the radiator to see if it is cold to the touch; if it is hot, the liquid inside may still be hot.
- Opening the system when the liquid is very hot could cause extremely dangerous splashes.
Step 2. Lift the vehicle
To gain access to the underside of the radiator and drain the fluid, you need to raise the car just enough to be able to work and put a collection container underneath. Identify the jack anchor points following the instructions in the user manual; in this way, you avoid damaging the bodywork or chassis during the procedure.
- When the car is high enough to slide in a container, put in support jacks to support its weight.
- Never work under a vehicle that is supported only by the jack. Jacks prevent the jack from losing pressure and dropping the car while you are under it.
Step 3. Open the drain valve to drain the liquid into the vessel
Find this element under the base of the radiator; generally, it has the appearance of a spout equipped with a valve to be rotated to open it and is placed on the bottom of the radiator or near it. When you have located the valve, make sure the collection vessel is positioned just below it and open it.
- The coolant should start coming out, but you should still be careful that it doesn't come in contact with bare skin.
- Read the user manual to find out how much fluid the system can hold and make sure the vessel has at least double the capacity.
Step 4. Wash the radiator with the garden hose
When the liquid stops flowing from the drain valve, it could still leave traces in the system. Close the drain opening and fill the cooling system tank with water. Start the engine and let it idle for a few minutes before draining the contents of the radiator again; repeat the procedure two or three times.
- If you leave the engine running for only a few minutes at a time, it shouldn't get too hot and you shouldn't have a hard time draining the radiator.
- The water rinses away any residual coolant from the engine.
Step 5. Fill the radiator with a mixture of water and antifreeze
Most vehicles need a mixture of equal parts water and coolant to maximize the effectiveness of the cooling system. Purchase a pre-mixed fluid or prepare it yourself; Fill the tank until the fluid level reaches the "full" mark and then start the engine. As it heats up, the thermostat opens and lets the coolant flow. As the fluid level drops, keep refilling the reservoir; continue pouring the mixture into the radiator or tank up to the maximum recommended quantity.
- If you don't have the car owner's manual, check the car manufacturer's website to find out the cooling system capacity of your model.
- It may take a few minutes for the refrigerant to run through the system, so be patient as you continue to pour in the new one.
- If your radiator has a relief valve on the top, open it and let the engine idle for a few minutes to expel any excess air.
Part 3 of 3: Seal a Radiator Leak
Step 1. Replace the radiator cap
An element that often presents some problems is the cap itself. It is designed to dissipate excess pressure and in this way avoid damage to the system; however, over time it is subject to oxidation, wear and dirt deposits. To replace the cap, unscrew it after waiting for the engine to become completely cold; at this point, screw in the new spare.
- You can purchase radiator caps at the auto parts store.
- Remember to request the specific cap for the make, model and year of production of your car.
Step 2. Use a commercial sealant
This product is available at most auto parts stores and can help you resolve a leak if you are in an emergency situation; however, be aware that sealants are not a permanent repair. To use one, just open the radiator cap and pour it into it. Top up with coolant and water if the leak has caused the level to drop.
- You will probably still need to locate and repair the source of the leak or change the cap after using the sealant.
- Sealants are a great solution if you need to go home or take the car to a repair shop.
Step 3. Close the visible holes with epoxy
If you can pinpoint the source of the leak in the radiator, you can fix it with this substance. First, carefully clean the surface surrounding the hole or crack, as dirt or grease prevents the resin from adhering tightly. Use a spray with brake cleaner and a rag to get rid of grease and deposits, then wait until the area is completely dry. Use your hands to knead the resin until it becomes malleable enough to spread all over the crack.
- Let the resin dry overnight before starting the engine.
- You can buy radiator epoxy at most auto parts stores.
Step 4. Replace the radiator
If there is a break on the body of this element, you will most likely have to buy a replacement. Drain all the coolant and disconnect the hoses that go in and out of the radiator. Remove the bolts from the brackets that hold the radiator in place and lift it straight up from the front of the engine compartment. Each car model has different mounting patterns, but radiators are typically secured with six bolts. Insert the replacement part in place of the damaged one and lock it using the same hardware.
- It may be necessary to remove the bodywork or cut the panels to gain access to the bolts or remove the radiator from the car.
- You can purchase a new radiator at an automobile dealership or at most auto parts stores.
