Changed out water pump and thermostat and vehicle runs high temperature what could be issue?

Reasons the Temperature Gauge Reads High

If the temperature gauge reads high, it could mean your engine is overheating. Another reason your reading might be high is you could be losing coolant. A small leak or evaporation may cause your radiator to slowly lose coolant. A third reason your temperature gauge reads high could be because the thermostat is broken. If this is the case, you may need a coolant temperature switch replacement. The last reason the temperature gauge could read high is because of a water pump, or water pump gasket failure. If the water pump is malfunctioning, it may need to be replaced by a professional.

What to Do If Your Temperature Gauge is High

If your temperature gauge is reading high, it means your car is overheating. This is a very serious matter and you should never drive an overheating car. If your car starts to overheat, shut off the air conditioner and open the windows immediately. If this does not reduce the overheating, turn on the heater as high as it can go. If this still doesn't work, pull over on the side of the road, turn off the engine, open the hood carefully, and wait until the vehicle cools down. Never open the radiator cap while the engine is hot - coolant can spray and burn you. Once the vehicle has cooled, take the car to a mechanic right away so they can diagnose the problem. Cars are especially susceptible to overheating in hot climates, like what's common in cities like Los Angeles, Phoenix, Las Vegas, or Atlanta.
The temperature gauge is an important tool in your vehicle that shows the temperature of your engine's coolant. Contact YourMechanic and have your car inspected for overheating if it reads too high, as this can cause serious problems...

Reasons the Temperature Gauge Reads Cold

On most vehicles, the temperature gauge reads cold until the engine has run for a few minutes. If the temperature gauge still reads cold after the engine has warmed up, the gauge may simply be broken. Another reason the temperature gauge could read cold is if the thermostat in the vehicle stays open. With the thermostat stuck open, the engine can be overcooled, causing a low temperature reading. If this is the case, the thermostat may need to be replaced.