The car overheats soon after I start it. The mechanic said I need to replace either the thermostat or the water pump.
I would agree with that mechanic, but it could also be low on coolant. I would check the level make sure its full, and then start it up, have a certified mechanic such as one from YourMechanic, feel the upper an lower radiator hoses and see if they are hot at all. They should be able to give you a proper diagnosis so that you can move on to a repair.
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