Coolant not reaching radiator

The coolant is not reaching the radiator. One of the hoses is not working.
Experienced mechanics share their insights in answering this question :
Hello. If coolant is not reaching the radiator, it is an indication that the coolant is not moving through the system properly. This could be caused by an air pocket in the system or a clogged hose. Another possibility could be that the water pump is not working properly. I would recommend you have your coolant system checked by a certified technician, such as one from YourMechanic, to determine exactly what is preventing the coolant from reaching the radiator.

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This issue could be caused by a faulty thermostat, an obstruction in the radiator, a fan or the water pump has malfunctioned preventing the coolant from flowing and dissipating heat as intended.
Start your car`s engine and allow it to idle. Look through the radiator filler neck to see if the coolant flows. At this time, it should not be flowing as your car has not reached the operating temperature to cause the thermostat to open. If you find the coolant is flowing, it means the thermostat valve is open.
If your coolant light is on, but the coolant is not low in the reservoir and it appears there are no leaks, then your vehicle may have a coolant sensor malfunction. A faulty coolant sensor can falsely trigger the dashboard warning light.
This is a common indication that something is wrong with the cooling system. It could be the result of a faulty radiator, a faulty thermostat, or other related problems. This problem can severely limit the vehicle`s functionality due to the engine`s poor performance.
Thermostat: The thermostat regulates the flow of coolant into the engine keeping it at its optimum operating temperature. The thermostat is closed when the engine is cold. As the engine heats up, the thermostat opens and allows coolant from the radiator to circulate.
There are several possible reasons. Your thermostat could be stuck closed or you may have a broken water pump belt. Both of these would prohibit the circulation of the water which is necessary to move the water from the engine to the radiator for cooling.
The coolant flows through the thin tubes that make up the core of the radiator and is cooled by the air flow through the radiator. From there, it flows out of the radiator, through the lower radiator hose and back to the water pump.
If the coolant level is dropping and there is no external leak evident, then the coolant is probably leaking internally, into the engine. If the car has recently overheated then this could have caused the head gasket to fail. If it has, it could be leaking coolant into the combustion chambers.
Technically speaking yes you can use plain water in your cooling system but it isn`t recommended as a long term solution and certainly not in extreme weather conditions.
An overheated engine is one of the most prominent signs that your radiator is clogged. If you notice that your car`s temperature gauge is reading higher than usual, it`s time to take your vehicle in for service. Signs of an overheating engine include: The temperature gauge needle moving into the red zone.
Push the hosepipe through the inlet and turn the water on. This will help flush out any sludge inside. Move the hosepipe around a bit to loosen some of the debris. If you have a rubber hammer, place a soft dust cloth and gentle tap the bottom of the radiator to dislodge any stock on sludge.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

No coolant in the reservoir. Seen low coolant message. I added 2 quarts of 50/50 coolant. Still getting the message. How much coolant doe it need?
ANSWER : Hi there. For the coolant light to go out, you would need to have the coolant between the low line and the full line for the light to go out. If the coolant is low and keeps on being low, then look for any signs of coolant leaks. You may have to use a coolant pressure tester to pressurize the reservoir to allow the leak to be found.

If you need further assistance with the coolant being low and the warning light being on, then seek out a professional, such as one from Your Mechanic, to help you.

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Radiator hose from cap to coolant reservoir broke off just below cap on radiator. Can repairs bbeen done without changing radiator? 2010 Nissan Armada
ANSWER : Hello – although this cooling system hose looks much like an octopus, it can be changed without removing the radiator. It does require small hands and a bit of "technique". For assistance, I would recommend a radiator hose service by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

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Over heating coolant not siphoning back into coolant over flow tank
ANSWER : Hey there:

It’s common for many mechanics to make the mistake of mis-diagnosing the cause of an overheating situation; especially when they assume it’s a thermostat issue. The problem could be caused by a blockage in the coolant tubes running from the radiator to the overflow tank and back to the radiator. However, it also may be due to air trapped in the coolant lines. I think a good idea would be to contact a different ASE certified mechanic, such as one from YourMechanic, and have them complete a coolant flush, which should remove any blockages in the coolant tubes and may solve your problem.

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overheating due to coolant loss with no leaking
ANSWER : Hi there. Completing a compression or pressure test might help diagnose the source of your problem, but I would suspect if you’re not finding a leak, that the issue is a blown head gasket. Two ways of determining if this is the case. First, check your engine oil. If the oil is milky, this means coolant is getting inside the engine oil galley’s some how, most likely due to a blown head gasket or cracked engine block. Second, check for signs of white smoke from the exhaust. This is also an indicator of coolant. Coolant has to go somewhere, and if you’re constantly running low on coolant and having consistent overheating problems; with no visible leak, the issue is probably internal.

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My car has a coolant leak
ANSWER : Hello. The most common cause of a random coolant loss on this vehicle is a leaking intake manifold gasket. It commonly starts leaking coolant into the engine, which will be burnt off or will leak externally. I typically do a pressure test and a dye test on the system first to see if I can locate an external leak. If nothing is found, then I do a block test to make sure that there is not a head gasket issue. If nothing shows up there, then I replace the intake gaskets. If you need to have this done, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose the coolant leak and replace the intake gaskets if necessary.

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Possible coolant in my oil but no oil in the coolant. Use about 1 l of coolant per 100km.
ANSWER : Check the transmission fluid. If all testing eliminates the head gasket, cracked cylinder head, etc, it may be a cracked radiator.Transmission fluid is sent forward to the radiator to be cooled. Ir runs into what is typically called the "side tanks" of the radiator. So the transmission fluid and coolant are both flowing through the radiator and kept apart just as the engine oil and coolant are kept apart in the engine by the head gasket, coolant and oil passages, etc. If the tank in the radiator is cracked internally, transmission fluid may actually be forced into the coolant as transmission fluid is under higher pressure than the coolant. Short of a cracked head gasket, cylinder head, or engine block, it’s really the only other source of any type of oil getting into the coolant unless the vehicle is equipped with an engine oil cooler as well.

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Green coolant accidentally mixed with red coolant
ANSWER : Hey there. The two coolant chemical compositions are different and may cause corrosive action or gelling of the mixture. If it becomes corrosive, it may damage gaskets and metal components in the engine. If the mixture becomes gelled, then it may clog the engine, radiator, thermostat, and heater core passages. The coolant should be drained as soon as possible and flushed out with water a couple times then put in fresh 50/50 mixture of correct coolant. A certified technician from YourMechanic can assist with a coolant flush and perform any other adjustments at your home or office if needed.

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Flushed coolant month ago now glitter in radiator
ANSWER : Hi there. Quite frequently when red and green coolant is mixed and inside the coolant tubes for a long time, it can cause excessive wear of the coolant tubes. The ’glitter’ you see may be excessive debris that may have worn off the coolant hoses. Whether or not you can continue to run with this coolant; it shouldn’t be a problem. However, I would recommend that the next time you flush your coolant, that you also replace the coolant hoses and tubes.

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