How long does it take for coolant to circulate after adding it in order for the car to heat up back to normal?
If you had told us the year make and model of your car we would have a better idea if your motor was cooled clockwise as with older cars or reverse cooled as most new cars and trucks are. If your cooling system is full, the coolant circulates slower in the Winter than the Summer because the thermostat would be normally not open as wide in the Winter to keep the engine and heater-core as it's normal operating temperature. People fail to realize is when a motor is started when it's stone cold, the water-pump IS circulating coolant through the heater-core even though the thermostat is closed tight. Depending on the size of your engine, direction of coolant flow and the cooling efficiency of the water-jackets makes an enormous difference how fast the heater warms up and when and how far open the thermostat opens.
Why can I hear coolant circulation in my car?
Coolant is circulating all around your engine, including down to your heater core (basically a mini-radiator that is inside the car). If the heater is set to "open" (or on) even a little bit, coolant will be circulating through there. Often times, the switch shows the heater is completely closed, but it actually is still open a tiny bit. Also, if there is any air in the cooling system, the coolant moving through the system will sound louder. For example, take a water bottle, fill it about 2/3 up with water, put the lid on it, and shake it back and forth. You can hear it plenty loud, right? Then, fill the bottle all the way to the top. Make sure you get all the air out. Then put the lid on it and shake it around again. This time, you don't hear anything. When the cooling system is properly filled, there is no air in it and you can't hear it. Bleed the system to get the air out...a video of that can be found here; http://www.videojug.com/film/how-to-bleed-your-radiator After bleeding it, top the system off. If the level drops, the vehicle overheats, or you can hear air in it again, get it checked out at a mechanic shop. All of those are signs of a leak somewhere, which can lead to huge issues down the road. Good luck!
Does coolant circulate if the thermostat is closed?
You're correct the antifreeze will not circulate if the thermostat is closed and the other commenters are correct also, adding water will totally DESTROY the engine, it causes RUST on the inside of the engine it is probably one of the worst things you can do to an engine, it's as bad as never changing the oil. Tell your brother to get under the truck and to drain the fluids out of his radiator via the plastic drain plug usually on the drivers side bottom of the radiator and replace it all with fresh antifreeze 50/50 either buy it 50/50 or mix it 50/50 with DISTILLED water. You can get it at the grocery store for less than a dollar usually. Probably be a good idea to replace the thermostat as well since I'm sure it's covered in rust too.
What prevents the engine coolant to circulate?
What can cause the engine coolant not to circulate, I'm sure there's a truck load of reasons.Water pump impeller is corroded or Brocken off of the press fit on the shaft has gone free floating. Effectively you don't have a water pump now or its effects are severely diminished. These problems are caused by using contaminated water, defective or wrong pump fitted and reconditioned pump respectively.Alternator drive belt, some water pumps are driven externally by the alternator drive belt or a separate belt altogether. If this breaks apart, overheating will be the first to manifest even before batteries go flat on you.Radiator thermostat mulfunction. The thermostat seperates water in tthe engine from water in the radiatot so that enging temperature raises fast unaffected by the cooling effects of the radiator. If it mulfunctions and stays closed, the engine will overheat as a result of lack of circulation. You can make a fast diagnosis by feeling the top and bottom hoses. If the bottom one is cold yet the top one is too hot, its definitely blocked thermostat.Air locked cooling system. Like all pump systems, an airlock is detrimental to efficiency of the pump action. The pump pushes and pulls water by seamlessly scooping it. Because Water is incompressible, movement is transmitted to the whole water body. If there are air pockets within the system, some of the pump action instead of moving water will compress or stretch are thereby rendering pump action ineffective. Some engines need to be bled after filling up with water after leakages or repairs.I'll ad more as they come to my head.
How do I know if my radiator is "blocked" (not circulating coolant)?
First make sure your thermostat is working, that is a much more common problem than a radiator being blocked.If you're sure your thermostat is working (either by carefully feeling the coolant hose coming out of it to confirm it is hot or going so far as to remove it completely as a test if it's easily accessible), then carefully see if the hose leaving the radiator is warm.If your radiator is partially blocked and causing coolant to go through it more slowly than it should, the symptoms should be variable with outside temperature and vehicle speed (whereas with a thermostat it should be pretty much the same under all conditions). For example, it will be hotter sitting in traffic than at highway speed. What is more common than an internally blocked radiator (though of course that does happen) is an externally blocked radiator where road debris and dried bugs are preventing air from passing through it and hampering its ability to cool things down. Visually inspect both the front and the back. If dirty, ou can literally take a garden hose to it and should notice a differnece immediately (if it is your problem). Even if it is not visibly dirty, make sure the air from the fan is passing through it to the engine side. And while we're on the topic of fans, make sure yours is working. That's also a much more common problem than an internally blocked radiator.Again, seriously, be careful, the components will be hot.
Why is the radiator coolant filling up the reservoir?
Your question needs a little clarification.If it fills constantly, to the point of overflowing, you have a leak in a head gasket that is adding oil to it. This is serious and should be fixed before more damage. You should notice a foam or sludge around the edges.If it varies between the max and min lines, it is perfect. It receives the excess coolant when it heats up, and sucks it back when cool.When you fill it after changing, you should fill close to the max level, and check the next day or two after driving those days. It will probably drop as it replaces air locked in the system on draining. Once it his it’s normal level, it should maintain that (above the min level) every morning when cold.
How do I know if my radiator is "blocked" (not circulating coolant)?
While engine is cold remove radiator cap and start engine. If you have a water thermometer insert it so you will know when your at running temperature, sometimes a meat thermometer will work. At running temperature you should see the water circulating in the radiator. Remember that low water is the main reason for overheating. You should add anti-freeze or a 50/50 solution. Water should be about one inch above the coils. If water isn't low check the fan belt, or electric cooling fan, it should come on as soon as the car begins to over heat. Now check the hoses they may be soft and collapsing when hot. The water pump usually leaks out the bottom when it go's out or the shaft becomes wobbly (you'll need to loosen the fan belt to check this). If you have to pull the thermostat don't bother checking it in boiling water just replace it with a new gasket, and remember the coils on the thermostat always go's in the block or manifold. Check for oil in water this could mean a bad head gasket which will also cause overheating.