Car is overheating, Just replaced Radiatior, Water Pump and Thermostat. All of the hoses have no leaks and are new.

A worn water pump is the most likely. If the coolant is going down, the water is going somewhere.

The most common reasons an Oldsmobile Alero is overheating are a coolant leak (water pump, radiator, hose etc.), the radiator fan, or a failed thermostat. Coolant leak (water pump, radiator, hose etc.)

Oldsmobile Alero Overheating - RepairPal

Videos on overheating. You probably have air in the system from when you replaced the thermostat. The coolant system needs 'burping' of air.

https://www.google.com/search?q=2000+Oldsmobile+Alero+running+ho

Burping

https://www.google.com/search?q=burping+coolant+system

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I have seen the water pump impeller go bad on a lot of jeep engines. Take off the top radiator hose and run the car. Run it long enough to have the thermostat open. Have a garden hose in the radiator inlet. See how much water flows through the hose.

Connie, Were the radiator,water pump and thermostat replaced to try and fix the over heat issue or as maintenance. Engine overheating can be caused by a lot of things, Leak in cooling system, air in system, bad rad. cap, slipping belt, faulty thermostat or installed upside down, faulty water pump, plugged radiator (inside/outside), collapsing rad hose, faulty cooling fan, leaking head gasket, sludge plugging engine water passages, poorly tuned engine, etc..
Take into a good shop for diagnoses and estimate for repair. Check the attached links,instruction and guides, Good luck
"I hope this helped you out, if so let me know by pressing the helpful button. Check out some of my other posts if you need more tips and info."
How to Troubleshoot an Overheating Engine
Steve Litt Overheating Guide
Diagnose Engine Overheating Auto Repair Help
How to Troubleshoot an Overheating Engine DoItYourself com

Un screw rad bleed . hose in radiatior . . loosen hoses and vent out . You can buy pressure pump to couple on top of radiator

The only other thing you need to do is get the radiatior flushed. If your certain you have a good water pump and the thermostat was not put in upside down, then that would be the only thing left that would hinder water flow. If you have a follow up question on thei get back to me and if this was helpful a vote on the thumbs up would be greatly appreciated.
Thanks

COULD BE THERMOSTAT IF TOP RADIATOR HOSE IS NOT HOT AND BOTTOM RADIATOR HOSE GOING TO WATER PUMP IS HOT THE THERMOSTAT STICKING PARTIALLY CLOSE.IF TOP HOSE IS HOT THE RADIATOR,ENGINE BLOCK HEATER CORE NEED FLUSHING OUT.IF WATER PUMP WEEP HOLE LEAKING REPLACE WATER PUMP, FAULTY WATER PUMP WILL CAUSE ENGINE TO OVER HEAT.REPLACE RADIATOR CAP MAKE SURE YOU HAVE 50 / 50 MIX SOLUTION ANTIFREEZE AND WATER IN COOLANT SYSTEM. IF ALL LOOKS GOOD CHECK ENGINE OIL ON DIP STICK, IF OIL IN DIP STICK LOOK LIKE MILKSHAKE YOU HAVE BLOWED HEAD GASKET THAT WILL CAUSE ENGINE OVERHEATING WHILE DRIVING CAR IN SHORT DISTANCE AND ENGINE OVERHEATING.

Your thermostat is located where the upper radiator hose connects to the engine under a housing. If it is not leaking there then check the bottom of your water pump. Look at it from underneath and you will see a small weep hole in the water pump housing. If it is leaking there your seal or bearing packing has gone bad. Simple solution- replace the water pump. The other reasons for overheating could be a stuck thermostat which will cause the vehicle to overheat within about 5-10 minutes after starting. The other cause could be a radiator that needs to be roded and cored because of to many deposits internally causing restricted flow of the coolant.The thermostat could be cracked or rusted out also. Try to gain access to a system pressurizer to find your leak. I have given you just about every scenario to check to find your problem. Good luck.

If you are going to the expense of replacing the head gasket, it would be false economy not to also replace the thermostat at the same time.
Particularly if you are attempting to solve a overheating problem.

Remove and raise upper hose at thermostat end and remove lower rad hose.
Fill rad with a hose and watch for flow from bottom rad hose and/ or bottom rad hose connecton.......water should fall though rad easily.
Honda rads are cheap.....any restriction....replace rad.

Remove thermostat....fill thermostat housing with hose and watch for water flow at bottom rad hose.
Flush good.

Remove heater hoses.......flush back and forth until a good flow is present "With heater control set to hot" if no or poor flow....replace heater core.

Stop leak can plug everything.

Also.......not likely causing over heating....but ....at your mileage,if you do not know if the timing belt has been changed.....CHANGE IT NOW!
Water pump is optional at this mileage.

Hello Ranger Joe, eight months and two radiators is very uncommon. Question, Have you visually confirmed the leak in the radiators or is the leak near the hose connections? Replacing the radiator, cap, water pump, & the thermostat leaves only two others, the hoses and the engine block/heads. Far fitched will be something or somebody poking holes in the radiator.