Water flow out from the overflow tube

thermostat is stuck closed need to replace it

The pipe from the pressure switch is either blocked, damaged or has become disconnected from the pressure switch ....so is not sensing the water level in the drum. From your filter you will see either a thin black or clear tube going upto the pressure switch - check this out. If damaged change; actually it is a simple fix. Spares can be located from this very site - fixya. Good water flow is gud, but after your wash see that the valve on the wall faucet is turned off.
If helped pl click so.

I think the leakage out of the reservoir is being caused by the overheating, not the other way round.

This can be caused by several things:

- failed thermostat (not opening)
- failed temperature sensor (not turning on the fans)
- blown fuse or failed relays in fan supply (if electric)
- soft hose from radiator to water pump "sucking in" and preventing flow
- blown head gasket allowing combustion gas into the water jacket (less likely)

More details in here

http://www.turboninjas.com/camry/eg2.pdf

If there is no water leakage, there are only two possible problems: First, you may have a bad thermostat which is not opening, making the engine overheat because no water is flowing through the radiator. Second, you have water getting out the exhaust, either from a bad head gasket or a cracked head or block. If you seem to have white smoke in the exhaust, this is your culprit, and it is an expensive repair.
When the engine is cold, fill it up, and then start it and let it idle for about 10 minutes. Feel the radiator or the upper hose, it should start getting warm. If not, you need to replace the thermostat. This should be a fairly easy and inexpensive repair. Also look for water anywhere under the car, you may have a leak somewhere that you have not noticed.
Otherwise, you are into major money to repair a bad head gasket or head/block.

Depends where it is leaking. If it is leaking on top of the transmission bell housing it is probably the o ring on the back of the thermostat housing. (there is a rather large tube that carries coolant from the water pump on the other side of the engine to the t stat housing.) If the leak is passenger side it could be the water pump or the o ring on the other side of the earlier mentioned tube ( the tube runs under the intake manifold in the V of the engine). Other areas it could be the heater hoses or the upper or lower radiator hoses. Also a bad head gasket will do it also, signs of that can be water in your oil ( oil that is tan in color is a sign of moisture ) but you still can have a blown head gasket without water in the oil. A leaking heater core can also be a problem (wet area on the passenger side floor can be a sign of this) Also a worn radiator cap can leak into the overflow bottle and out on the ground. A sign of this is a over flow bottle that is completely full inspect the rubber seal an the cap or just replace it. The t stat housing problem is unique to the 2.5 v6 and the housing is tricky to remove. I described this procedure on wiki answer. Google - Thermostat housing 2.5 v6 water pipe 1996 and you will find it the instructions apply actually to a 1999 but is similar for most chrysler 2.5 v6's

did u check the themostat? if that is good do a water pump flow test to make sure the pump is pumping do this test when the engine is cold. if not do a radiator flow test to see how the water flows through radiator with gravity alone

I had this problem with my 6.0L diesel. It turned out to be the head gasket. Compression psi was getting into the water jacket in the cylinder head and forcing all the water out through the overflow bottle. Check the psi of the overflow water reservoir, especially under load (acceleration, etc).

The overflow system has a different radiator cap than on yesteryears cars. The old cap would let extra water vent out of the radiator and you would lose that coolant. The newer radiator cap lets water go both ways through the vent tube. Then the overflow uses a tank to catch and return the water. It siphons the fluid back into the radiator.

The system was invented when the thermostats were set at 205degrees and up for pollution systems. It also saved some aluminum with smaller radiators and using a plastic overflow bottle instead of a bigger metal radiator.

There are two possible reasons for this. The most likley one is the AC drain tube that sticks out from underneath the passenger side floor boards. This is a black rubber tube made of rubber and has a pinch at the end. You've got to take something like a pencil and clean out any debris(leaves, ferns etc.) and this will allow the condensate from the AC to drain out. Two is you may have a heater core leakage.

Yes. I have done it many times.