Water leaking out of hole next to thermostate

If the radiator is spraying coolant from the fin area, you should either have it recored, or replace it. Generally, it is not practical to repair a radiator core that is leaking due to corrosion - it will soon spring a leak from some other spot. (recoring: remove the pans and put them on a new core). Rock Auto sells new radiators ranging in price from $95.79 to $250.89. The same radiator is used for both engine models, and also in the Dodge Dakota from the same year.

Cooling system corrosion is the result of failing to change the coolant when specified, or of using tap water with a high ionic content (this is especially a problem in the Southwest US). Skimping on the anti-freeze also leads to corrosion; anti-freeze contains corrosion inhibiting compounds, and it raises the boiling temperature of the coolant so it can perform its function over a wider range of conditions (liquid can remove more heat per volume unit than steam). Keeping the system properly pressurized (leak-free) also raises the boiling point. If your tap water is problematic, use deionized water (the water from a household dehumidifier is excellent if the dehumidifier is reasonably clean).

If you must add coolant to an overheated engine, do so slowly, while the engine is running to minimize thermal shock to the system. You want to cool the engine down evenly to avoid cracking anything. Keeping the engine running circulates the coolant to prevent sudden cold spots. It also helps to prevent bearing seizure - see the next paragraph. Add your coolant to the overflow tank first - it is dangerous to remove the radiator cap on an overheated engine.

Continually overheating the engine will damage it - the oil breaks down and turns to varnish in the bearings, and there is a possibility of cracking the block or a head from thermal stresses beyond design limits. Check the quality of your engine oil right away to see if it is breaking down; if so, change it.
RockAuto Parts Catalog

you must have a black hole some where in your engine,lol. but seriously the fluid must have been refilling the radiator from there it must be leaking out some where, check your oil level for anti freeze contamination. check the tattle tale hole on the water pump for any leaks there.park the car and check fluid levels cold start car and let warm up untill thermostate opens then check for leaks

follow this steps and fix it. God bless you

1. Determine the Reason for Water Pump Failure
   • 1 Repair a water pump by checking your car for a failure in the bearings. You can test for bearing failure by seeing if there is any play in the shaft that is connected to the electrical fan blades, as well as the drive pulley to the pump itself.
     
   • 2 If you notice any free play in the shaft or the pulley, you will need to take the pump apart and replace the bearings.
     
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   • 3 Determine if the water pump failure is due to a leak in the casing. Examine the water pump housing for leaking or water stains in the drainage hole next to the pulley.
     
   • 4 If water is dripping from this hole, then the seals inside the pump need to replaced in order to repair the pump.
     
   Remove the Water Pump for Repair
   • 5 Allow the engine to cool completely before removing any part of the cooling system. Never open a radiator cap or plug while the engine is still warm.
     
   • 6 Disconnect the car battery. This will prevent the electrical fan from turning on while you are under the hood.
     
   • 7 Drain the radiator of all fluid and disconnect the radiator hoses. Collect the fluid with a plastic container and keep it in a safe place until you are ready to put it back into the radiator.
     
   • 8 Remove the fan assembly. This will include the shroud, the fan and the fan belt. Disconnect the electrical leads for the fan.
     
   • 9 Remove the pulley for the fan belt as well in order to have access to the water pump.
     
   • 10 Use a socket set to remove the water pump from its engine mount.
     
   • 11 Open the housing for the water pump and replace the seals or bearing as necessary. Some auto parts stores carry repair kits that have both the seals and bearings for specific types of water pumps.
     
   • 12 Reassemble the cooling system by replacing the water pump, pulley, fan belt, fan assembly and radiator hoses. Refill the radiator with the fluid.
     
   • 13 Start the engine to see if the water pump repair was successful. Check for leaks before you take the car out on the road.
     

Check to see if your fan is coming on. if it is then check the middle of your radiator if it is cool while the outside is hot you have plugged radiator

Well there are only 3 things that could have gone wrong.

1. Radiator Leak - this means the radiator has developed a hole with via corrosion of the metal parts of simply integrity failure of the plastic parts of the radiator.
2. Hose leak - this could be a hole in 1 of 2 hoses that connects the engine to the radiator. Or it can also be a leak where the hose connects to the radiator (clamp Failure).
3. Water Pump breakdown - this is where the gasket in the water pump has failed and is leaking out the water rather than pumping it.

All the problems above has different ways of diagnosing. but we can probably narrow it down.

1. if the leak is near the radiator then it could be a hose connection, hose breakage or Radiator hole.

2. if the leak is nearer the engine then check the other end of the hose and if its not there then it could only be the water pump is leaking. You can check this if there are water stains on the water pump. The water pump on a 1990 corolla is mechanical turned also by a fan belt. Look for a pulley that has a hose connected to the radiator and that would be the water pump.

There are products out there like stop leak that MIGHT stop the radiator leak. However... the only real repair is either to have it soldered (if the end caps are not plastic) or replace the radiator all together.

Adding a product like "Stop Leak" most often starts to introduce other problems to your vehicle like a future water pump seal failure or clogs in the smaller water passages in the engine block, heads and manifolds and the thermostat heater bypass hole. Anyone that has ever done any major engine repairs will know immediately if stop leak was used in a cooling system.

The best fix is to replace the radiator.

Many radiators today can not be repaired

Stop leak is in most any auto parts store. Just be advised of what you can expect down the road.

specifically

1. warmer than usual engine operating temps
2. water pump seal failure
3. heatrer core clog (no heat)
4. passenger heat control temp valve clog (no heat)
The choice is yours. Personally I would not do the "Stop Leak" treatment attempt. Sometimes it works other times it does not.

water pump is leaking.Change it as soon as possible.

It sounds like your water pump may have gone bad. The water pump pushes the antifreeze through the engine, heater core and Radiator which is regulated by the thermostate. Sorry for the bad news but i hope this helps, and Good luck

try to flush the system wit presure water stright and reverse but make sure before flushing u must took the thrmostate out from housing and thermostate must be in right possion .

1. start the engine and leave the radiator cap open.
2. put a cardboard cover or a rug in the front of you radiator.
3. let it runs 20 minutes or more, see if it is overheated and see the water or coolant in the radiator circulated or not. If not, as soon as you have already changed water pump. thermostate and check the hoses, no leak, I think your radiator was blocked.

Did you put stop leak before?