My car was overheating before, and notice water leaking from it. So I took it to mechanic he said it was the water pump that needed to be changed. So I had him work on it and change it. The car drove fine for a couple of weeks, Just today the gauge started to rise. It was getting real got again!!!! I dont know what it could be at this point. Checked the coolant and it was fine, and does not seem to be leaking anything. Any suggestions...

Question edited for clarity
Question moved to category.

Water leaks don't cause overheating unless there is no, or very little coolant..

Air locks cause overheating.
Failed water pumps cause overheating.
Blocked radiators cause overheating.
Stuck thermostats cause overheating.

https://www.fixya.com/cars/r29872074-vehicle_cooling_system_no_heat

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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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Its real common for the water pumps to go on those especially with a 2.7 liter

goodyear are tyre mechanics
water in the oil is from a hole in the housing (aluminium timing chain cover ) behind the water pump impeller or problem head
before anything was replaced , a compression test should have been done to determine the condition of the head and head gasket
next a coolant pressure test should have been done to determine if there was a leak in the cooling system ( the housing crack would have been obvious at the test
water pumps always work if there is water for them to work in and only need replacing if there is a water leak from a hole in the housing ( seal failure ) or there is a failed bearing noise
I could suggest that you find an accredited professional service center that has experience on your make of car and get a proper diagnosis before you waste any more time and money on tire mechanics

Hello.
Recomend you to take a look under water pump
if you see coolant leaking, water pump is gonna be the problem

I AM LOOKING AT THE RADIATOR CORE LEAKING OR ITS PLASTIC SIDE TANKS.CHECK WATER PUMP WEEP HOLE IT WILL LEAK OUT COOLANT WHEN PUMP GOES BAD IT WILL CAUSE OVERHEATING.CHECK THE CYLINDER BLOCK CORE PLUGS SOMETIMES THEY WILL GO BAD AND LEAK OUT COOLANT.

Hello There

It's the water pump. One of the most common problems with the VW/Audi's. It was never the head.

Hope this helps. Please don't forget to rate me.

Thanks

Is your cooling fan kicking on when temp rises?Are you running antifreeze or just water?Possible calcium buildup in radiator or water pump not working at full potential.. I could be more helpful if more detail info was given....

It could be your head gasket.

leaking