I have a 1991 geo storm base 1.6 L it has a pully making noise when engine starts its loosing coolant and it bubbles over from the overflow reserve when engine is shut off does that sound like a water

1991 GEO STORM 1.6L 4-cyl Engine Code 5 DOHCCAPACITIES
Engine, with filter.......... 3.2 quarts
Cooling System, W/ MT Initial Fill.......... 7.4 quarts
Cooling System, W/ AT Initial Fill.......... 8.0 quarts
Automatic Transmission, Initial Fill........ 4.3 quarts [1]
Automatic Transmission, Total Fill......... 7.0 quarts
Manual Transmission, ..........4.0 pints[1] With ENG at operating temperature, shift through all gears.
Check fluid level in PARK and add fluid as needed.1991 GEO STORM 1.6L 4-cyl Engine Code 6 SOHC
1992 GEO STORM 1.8L 4-cyl Engine Code 8 DOHCCAPACITIES
Engine, with filter.......... 4.0 quarts
Cooling System, W/ AT Initial Fill.......... 8.0 quarts
Cooling System, W MT Initial Fill........... 7.4 quarts
Automatic Transmission, Initial Fill........ 4.3 quarts [1]
Automatic Transmission, Total Fill......... 7.0 quarts
Manual Transmission, .......... 4.0 pints[1] With ENG at operating temperature, shift through all gears.
Check fluid level in PARK and add fluid as needed.

you have a blown headgasket

You know the water pump is bad if it is leaking,making a horible noise like the engine is going to blow with the pully moving like it was loose,or if there is no circulation of coolant in the radiator.

Check coolant levels in the radiator and the overflow resevoir. You may have blockage in the radiatior and you could have a sticking thermostat.

When the car is completely cool,check the electric fan(s) for smooth rotation.

Clean/check/change the thermo sensor,contact and wire.

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Excavate air pocket in coolant system / check for head gasket leak

This test will kill two birds with one stone.

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MAKE SURE THE COOLANT SYSTEM and ENGINE IS COLD!

RAN THIS TEST IN A WELL VENTILATED AREA ONLY!

You will spill some coolant during this air pocket purge test.......BE KIND TO THE ENVIRONMENT and ANIMAL please clean up after the test!

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Put the front end on a pair of ramp or park your car on a VERY STEEP HILL (radiator facing top of the hill) .

Top of the coolant reserve tank

Let it ran for 10-15 minutes.

Monitor for air pockets escaping from coolant reserve tank.

Small amount of bubbles is OK at 1-5 minute mark

After the thermostat open up (after 195 F warm up) at
5-12 minute mark or after high idle you should see less bubbles.

If you do not see any in rush of bubbles then your thermostat may be partially stuck or rusted badly inside the thermostat hosing.

Give the thermostat host few gentle taps.

If you see larger bubbles surfacing after 15 minutes then should do a hydrocarbon (HC) dye test to test for potential head gasket leak.

Let engine cold down and top off coolant reserve tank.

Start monitor for coolant lost

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A coolant flush is require every 2 years or 24,000 miles.

I recommend the thermostat that has a relief pop-let to reduce the change of burst radiator and coolant hoses.

Make sure you get a new thermostat gasket,black RTV and fresh coolant for the job.

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You have a thermostat stuck shut. This causes pressure build up causing the over flow. As the heat increases the pressure increases. Also the water pump cant circulate the water also helping to add the pressure.

check fuse and relay, check your coolant to make sure it isn't low, Can you jump the fan to see if the fan will work? If fan works, possibly coolant sensor.

there is a small mark on the cam pully that must point strait down to the mark on the crank shaft timing pully. the mark on the crank pully is a bit hard to see but it is a low spot on the inside area. also lines up with the keyway grove in the pully.