Engine overheats but not leaking at waterpump and not having any coolant loss out of exhaust. pressure builds and water boils out of overflow tank if i loosen radiator cap. waterpump makes whining noi

This expansion tank is only when coolant builds up so musch temperature and pressure that it needs to release, so it relieves itself from the radiator into the expansion tank.
Then, when coolant returns back to normal operating temperature, the pressurized air contracts, forming a negative pressure or vacuum, sucking the now-cooler coolant mix back in to the radiator and cooling system.
So if your water is not getting to the bottle at all, even when engine is boiling, check the outlet and overflow line for blockages, the stem-valve in the bottle is moving, pressure/water leaks in the cooling system venting water or steam.
Also check radiator cap is correct for the car model and operating.

You have a coolant leak. The engine gets hot and pushes coolant out under pressure into the overflow tank.When it cools, the volume of coolant decreases, the pressure drops to the point that it becomes a vacuum. The vacuum pulls in air more easily than coolant. It's thinner. So, you keep losing coolant from the radiator which makes the engine run hotter, each time until it eventually overheats and does damage. You need to have the cooling system pressure tested. The leak will show up. Usually, it's a loose hose clamp or cracked radiator tank high up, which makes it had to see the coolant because it doesn't leak much and it boils off leaving little or no evidence. Fill the system completely before pressure testing. Remember, checking the overflow tank means nothing when checking coolant level. There's no short-cut to checking the coolant level, take the radiator cap off when cold to accurately check level. Read the safety precautions on the car but always check when the engine is cold. NEVER HOT.

Could be a defective radiator cap, or a leaking head gasket.

Doesn't sound like it ran hot enough or long enough to crack or warp the head. If there is a crack, the engine will continue to overheat. If a warped head, car would probably run rough, the affected cylinders would likely have little or no compression, there would be a noticeable miss, and overheating would continue.
Why the low coolant? It's a sealed system, so should never have to add coolant, other than a small loss from evaporation in the overflow tank. Monitor the level closely for the next few days. Note the level in the overflow tank to see if it drops over time. Leaks can be external anywhere in the coolant system-engine, radiator, hoses, heater core- or internal in the engine-head gasket failures can cause coolant in the cylinders (white smoke out the exhaust), or coolant in the oil (oil will have a milky brown look to it), or oil in the coolant (will see traces of oil in the radiator).
A couple of tests may be called for. A pressure test of the coolant system will check if the system holds pressure as it should-about 15 psi. If pressure does not hold, there is a leak somewhere. Water pumps usually leak through the weep hole when they fail. A radiator leak would show up when pressure is applied. If pressure does hold, check if you have a good radiator cap-the cap is what seals the system so pressure will maintain. Coolant under pressure raises it's boiling point by about 10 degrees, so is critical to keep the system under pressure.
If you suspect further problems-losing coolant or continued overheating-then have the chemical test done to check for exhaust gasses in the coolant. Basically a check if the head gasket is good, a simple test done at the radiator cap opening with a special fluid that changes color if hydrocarbons are present in the cooling system.
Or you could have a compression test of the cylinders to check the internal mechanical condition-not only tells you if head gasket is good, also tells you a lot about engine condition-even,. balanced, good compression in all cylinders translates into good power output-rings are good, valves are sealing good, all systems go.
The cooling system: water pump, thermostat, radiator, hoses, heater core and hoses, radiator cap, overflow tank, and the cooling fans and associated wiring. Make sure everything is working right and you'll be good to go.

Check for white smoke out the exhaust. If you have white smoke then you are burning coolant and probably have a blown headgasket. Another way for checking a blown headgasket is to open the coolant overflow tank and run the car. If you see constant bubbles in the coolant then you have a blown headgasket.

DO NOT DRIVE YOUR CAR IF the gasket it blown as the engine will overheat and the cylinder head can warp/crack.

If there is no white smoke from the exhaust and no bubbles in the coolant system there is probably jsut a leak in the coolant system, visually check all the pipes and check around the waterpump housing for leaks. If you can't see a leak then pressure test the coolant system. A pressure test will push coolant out the leak and should help you find where it is.

Hope this helps

you have a blown head gasket.. doesn't have to have coolant in the oil for a blown head gasket... if hoses are rock hard when running then you have exhaust leaking into the coolant via a blown head gasket...

Either the thermostat is stuck in the closed position...or the engine cooling system cannot pressurize...both will cause an overheat condition.
A blown head gasket can cause overheat condition as well as fluid loss (boil over)

I'd maybe remove the thermostat and either just replace it or not have a thermostat installed just to see if it still boils over. If it boils over with no thermostat installed then you're getting into possible leak in cooling system...i.e. water pump weep hole, hose or radiator leak...or a blown head gasket.

Hope this helps...

It could be the water pump , or something else , like a faulty thermostat. Where is the coolant leaking from ? If it is leaking from the water pump , then yes , your pump might be toast.
If the thermostat is no good , the engine will warm up to normal temp , and then overheat quite quickly. As it overheats and the coolant expands and boils , it could back up into the overflow reservoir and leak out onto the ground. You need to get someone to diagnose the problem ASAP , running your engine in an overheat condition could very quickly blow your head gasket and/or warp a cylinder head. If you can , please post a bit more info. Does it run but at a higher than normal temp. Does it only overheat when stopped in traffic etc.
Could be water pump , or thermostat , or plugged up radiator , or nonfunctioning cooling fans.

It appears that you have a minor leak at where a hose attaches to an engine or radiator pipe. When the engine is hot any leak will evaporate quickly and therefore not be seen. As the coolant heats up it will expand into the overflow tank but once the engine is stopped the extra heat build up will force the coolant out the leaking joint. As the engine cools, the leak prevents the coolant from being sucked back from the overflow tank.

The heater hoses and those pesky little bypass hoses in the cooling system tend to go hard and split if they are over 10 years old. Check all hoses and clamps for a good tight fit and replace any hoses that have gone hard or have become soft and stretched. Those spring type hose clamps tend to be less effective in clamping as the hoses age. Worm drive ones are the best to use.

If unsure take vehicle to a cooling system specialist and have them do a pressure test and more thorough diagnosis.

If problem persists, then it could indicate a problem with the head gasket (Usually caused by allowing engine to become excessively overheated when cooling system has run dry) allowing very hot high pressure combustion gases into the engine water jacket, which super heats the coolant in the engine block, which then boils off, and is released via the cap or any leaks. If the head gasket is really bad it will leak water into the cylinders and into the oil in the sump. This is indicated by an emulsion of water and oil mix on the dipstick. You will also see white smoke (water vapour) from the exhaust.

do you see fluid leaking anywhere?if not then you have an internal leak. check oil dip stick, pull it out and look to see if its a milky color or you could take off the oil fill cap and it will looks similar and have a build up of goo on the inside of the cap. Another sure fire way is to hold a piece of card board up to your exhaust and see if it collects water condensation on it. Some time though its obvious and water will be puddling near the pipe with a larger than normal vapor cloud. One more way to tell is to wait till car has cooled then top off with water, now dont add anymore coolant because you'd just be wasting it anyway and start the car and watch with the cap off and if you start to see a lot off bubbles forming then you know you got either a cracked head or a blown head gasket. but if your lucky it might be that your thermostat it stuck closed and this is prematurely boiling off the coolant...and make sure that you see the radiator fan come on, this to will cause overheating. Now to protect the engine from overheating while doing all these test, have the heater running anytime you see it overheat, this will dump the cooler water from the heater lines into the engine and bring it down a couple notches. while the engine is hot and running you've got to inspect all your hoses or at least get your car pressure checked, they will pump it up to about 16psi and it should hold for at least a good ten minutes if it start to drop in pressure then you have an internal leak.
but if the coolant is just boiling over you could have a bad radiator cap waterpump, or thermostat...and heres a quick way to tell if the system is operating normally. top of radiator again if needs it with water, install cap, start car and put your hand over the upper radiator hose...you shouldnt feel any water or pressure going through the hose.. but when it reaches normal operating temp and hopefully you also hear your fan come on, put your hand on the hose again..now it should be hot and give it a squeeze and let go..you should feel a slight back pressure this will mean the pump and thermostat is working. Now look in the overflow bottle is it starting to overfil rapidly? if not then you radiator cap is working also..but if you see small bubbles coming up out of the overflow tank this means exhaust gases are leaking into the coolant system. You can go to a shop and have a "Block Check" done it consist of a blue dye and a sample of your coolant is mixed with this.. if it turns green then you know positively that you have a blown gasket. i hope you dont because these repair cost quite a bit. good luck i hope its just boiling over.