Water flows out from the hole below the water pump cover

I am thinking blown head gasket either as the initial cause or because of the overheating. do a compression test on cylinders to rule out blown headgasket, check water pump by leaving cap off and watching flow of cooling system be safe at all times though check waterpump weep hole for leaks also check thermostat operation make sure both upper and lower radiator hoses are equally warm and one of them is not cold which usually means thermostat is stuck in closed position.

my 98 Blazer I had to replace radiator water pump heatercore and hoses. Had head gasket go. Once that happens air and dexcool corrode cooling system. Do you smell antifreeze? Are you loosing antifreeze? Check oil see if its another color not clear or black but i think light brown. Have you flushed out system?

Hi Jason.
Sounds like you are on the right track with the flow of hot coolant not stopping. Check your heater control valve to make sure it is stopping the flow of coolant through the rear heater core. Let me know. Hope this helps.

Most of the time a water pump give a warning when it is about to go. The warning is a small coolant leak at what is called a weep hole in the water pump itself. This weep hole is to let us know when the seal is going bad or a bearing has worn to it's limit. Most water pumps now days do not break an impeller, where everything else is in good shape and no water is being moved. If you have been seeing a coolant leak at or around the passenger side engine compartment, that has gotten worse, as you drive and she gets hot. That might be your water pump. Other wise you may have some other problem. Such as, the cooling fan not coming on when is should. Bad coolant thermostat, the thermostat would be the most common problem, (most likely to cause overheating problems). The water pump is driven by your timing belt an will need to be replaced also if the pump is found to be bad. to check your cooling fan circuit, start with the fuse box. Look for any blown fuses. Next check your fan itself, It should run when the engine is warm and also should come on with the A/C on. If you engine is very warm, w/ A/C off, the fan should cycle on/off to keep air flow over the rad. If you can drive for 20 miles non stop and your gage stays in the normal zone then have to sit in stop/go traffic and the gage goes up in the red until you move again this is an indication that the fan is not coming on when it should. Have that check first. Hope this helps FixYa up.

Could be a faulty water pump, clogged or stuck Thermostat or clogged radiator. Once the engine cools down remove the radiator cap then start the engine and wait for it to warm up to operating temperature. At operating temp you should be able to see the fluid in the radiator circulate. If you don't then you need to let the engine cool again and remove the thermostat or replace it. And run the same test again. If you still don't see the fluid circulate then replace the water pump.

HOW CAN I CHANGE BATTERY ON MY KLE 400

You may have vapour lock in your heater lines. Start engine, put heat lever on high, disconnect one of the lines on your heater core, the one on the flow out side, & see if you have any air coming out. Once antifreese comes out stick line back on & retighten clamp. Make sure your cooling system is topped off. Also your water pump may not be functionihg to it's maximum. Take rad cap off cold & view flow rate. If inadequate you may have to replace the water pump. Good luck!

Yes the water pump does run of the timing belt system.
Directly from the service manual:

The 3.5L water pump has a die cast aluminum
housing and a plastic swept vane impeller. It bolts
directly to the right rear timing belt cover using an
O-ring for sealing. The water pump is
driven by the engine timing belt.

REMOVAL
The water pump on all models can be replaced
without discharging the air conditioning system.
WARNING: DO NOT REMOVE PRESSURE CAP
WITH THE SYSTEM HOT AND UNDER PRESSURE
BECAUSE SERIOUS BURNS FROM COOLANT CAN
OCCUR.

NOTE: It is normal for the water pump to weep a
small amount of coolant from the weep hole (black
stain on water pump body). Do not replace the
water pump if this condition exists. Replace the
water pump if a heavy deposit or a steady flow of
engine coolant is evident on water pump body from
the weep hole (shaft seal failure). Be sure to perform
a thorough analysis before replacing water
pump.

(1) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).

(2) Remove accessory drive belts (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).

NOTE: The water pump is driven by the timing belt.

(3) Remove engine timing belt (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT AND
SPROCKETS - REMOVAL).

(4) Remove water pump mounting bolts (Fig. 31).
Note position of longer bolt for proper re-installation.

(5) Remove water pump body from engine

Here is link to get a factory service manual relatively cheap.
2004 Chrysler 300M Service Manual Covers every serviceable part.

Make sure you have water to the unit, the water pump is on and the fan is working. No water=no cooling.

Drain stopped up.
Take out the bottom drawer in the freezer, look at the back wall and you should get a partial view of the bottom of the cooling coils. Directly below these coils is the drain area. You may need a light to see the drain hole. If this area is covered with ice then a hair dryer will help clear this so you can see the drain hole.
I have some O2 tubing that I put down the drain to clear any cloggs. Also, I seal the top of the drain hole around the O2 tubing with tape and use the air from my lungs to clear the drain tube. Pour a little water down this drain hole to make sure it’s clear.