Loose change keeps getting into the water pump and then the pump goes out.

try a large pair of channel locks to remove the old pump, you are not worried about messing up the old pump, it is already bad, you just do not want to mess up the housing.

it is possible that the water pump fins are wore out so the water pump isn't moving enough water. replace the water pump.

The water pump is on the top right hand side of the engine if you standing on the passenger side looking at the front of the engine. Keep in mind that the water pump only goes back on one way, so make sure that you have it clocked right or the bolts wont line back up. Remove the water pump pully first before you take the belt off. This makes it easier to break the pully bolts loose and then remove the water pump bolts. Then after, put the pully back on and then the belt and then tighten the pully bolts, the belt will help hod the pully for you.

I don't know how you do this so I hope this is not telling you something you know.
1. Make sure that there are no leaks in the suction line from the pump inlet down to where the piping goes under water.
2. Fill the pump body with water through the discharge piping.
3. Keep the discharge valve open and turn on the pump.
4. Wait and listen, pump sound should change as air is discharged through the open line and water gets closer to the pump.
Gary

Check the pump for debris .

Ventilate message

That means the pump needs to be primed by running water through the wand. Push the water button and open the knob on the right. You will hear the pump change tone when it primes and the light or message will disappear. If you have a restriction in the intake line the message will not go away. There is a flow meter inside the machine that measures water flow. If the flow meter does not spin when the pump is running, the computer thinks that the pump is not primed. Coffee grounds can get into the intake and restrict the flow meter. If you get a restriction in the water intake (below the water tank, on the machine) the pump may run and water comes out, but the flow meter does not create the jet of water to spin the turbine wheel to send impulses to the computer. You get the ventilate message. One thing to remember is when you are working on the water system (have the water tank off) do not fill the bean hopper and visa versa. Keep them covered when working on the other. Cross contamination will damage a machine fast
The first thing that I would check is the tip of the steam wand for a plug. If that is clear then I would suspect a clogged flow meter. If you can get the flow meter out it twists apart and don't loose the parts and the dot on the turbine goes up. Clean out the small opening on the bottom pipes where the hoses attach. Look inside and make sure that they are clear before reassembling.

those cars have plastic water pump impellers that like to vrack and come loose from the shaft.if all else checkes out replace water pump

There is only 4 bolts that hold the pump to the block If you have the 4 bolts removed then hit the hub that the water pump pulley goes on with a hammer. some times you may have to hit it 3 or 4 good whacks. Hope this helps.

you need to drop the sub-frame. thats the only way