Overheating

Trying to tell if it is the water pump is not easy. So to determine it is a failed pump that is not leaking is to eliminate all other options. The most common causes of overheating are stuck closed thermostats and clogged radiators. Also, cooling fans that are not operating.

So I would suggest running the engine when it starts to overheat and check the fans on the back of the radiator to make sure they are on. If they are, pull the thermostat out and put it in a pot of boiling water and see if it opens. If it does, flush the radiator with the lower hose off and see what the flow is like coming out of the bottom hose. If it doesn't appear sufficient then I would suspect it is plugged.

Here are some guides that will help with this info. Let us know what you find. Thanks

https://www.2carpros.com/articles/engine-overheating-or-running-hot

https://www.2carpros.com/articles/symptoms-of-an-overheating-engine

Looks like this question is a duplicate. Please just respond to one of them.

The water pump normally fails by leaking or the bearing is making noise. If it is not leaking or noisy then it is probably just fine. There are blades on the inside of the water pump and as long as it is spinning then it is working. The only way it would not is if you run straight water and no coolant for a long period of time and those blades rust away. Otherwise, you have another issue causing your overheating. Please refer to the first post on this to get those details. Thanks

https://www.2carpros.com/questions/over-heating-62123867

What is the problem?

Typically the only test is a visual one for leakage. If you list the engine size, I can tell you if it is driven by the timing belt. If it is, it is standard practice that professionals will want to replace it, along with tensioners and idler pulleys, when replacing the timing belt, to insure a quality repair. With that style, it is not unheard of for the bearings to be worn out, yet it isn't leaking coolant. If the bearings fail, it can lead to valve damage if it is an interference engine design.