I just got my water outlet replace now my car is over heating

Possible trapped in system. Bleed system, should have two small screw bleeders, one in front of left valve cover on pipe behind water pump and the other on coolant pipe outlet as you follow upper rad. hose towards engine. Engine cool, remove rad cap, open both bleed screws and fill rad until coolant flows free out both bleed ports. close both bleed screws, rad cap off, start engine and let idle until upper hose is hot to touch , shut off, let it cool down for 20 minutes, top up rad and install cap. restart car ,drive and check.

Look for an air block in the heater core, or a water valve in the heater hoses that may be closed. The normal way to purge air from the coolant system is to run the engine with heater on high heat, and with the radiator cap off, until the thermostat opens and the engine is at normal operating temperature. Then shut off engine, top up the radiator and overflow tank, and replace the radiator cap. If hot coolant is still not circulating through the heater core, you may have to get inventive and crack the outlet line loose to get flow started.

Move to Arizona?

flush the heater rad out with a garden hose ,reversing the flow about 3 times and see what happens

Replace your overflow tank cap. This is a small problem that a lot of people overlook and end up replacing everything. What happens is the heated water and engine heat causes the seal to break down, and overtime the cap/seal can no longer hold pressure which causes the car to have a high temp or over heat. It will also cause you to lose coolant sometimes if you find yourself refilling on a regular basis. Try a new cap or have yours pressure checked at a local store. A new cap is $7-$12

Assuming your coolant is right full, and you've changed the thermostat, it could be the water pump (these usually start to leak or make noise if they go bad), but I would check the condition of your radiator first. If it hasn't been replaced or flushed out in 15 years it could be plugged, restricting coolant flow and causing your car to overheat.

If the engine overheated while driving, damage to the cylinder head gasket or engine block/cylinder head may have been done, which would prevent the vehicle from starting.

A standard engine compression check will tell the tale.

There is a separate T-piece 3way thermostat made by BMW for the old box shaped 318i and 518i cars. It is a separate unit that fits into the water pipes, and not onto the engine. It has a hot water inlet, and a hot water to radiator outlet, and an engine warming outlet. Each outlet has a thermostat. The radiator on opens when the water is hot, and the engine warming closes when the water gets too hot. The temp stays at 85 D Celsius all the time. Works well on my vw synchco bus and subaru 2.5 engine.

Need to check your radiator flow, and thermostat, start the engine cold, with radiator cap off, watch for the water in the radiator, when it starts to bubble over let it, keep water hose close, radiator should blow back till the thermostat opens, the water will go down, and add more water if needed, and put the cap back on,,,, if your thermostat is stick closed it will cause over heating......and you may have to have it replaced.

if standing on passenger side of car looking at the engine the belt will be in front of you the water pump is down at the bottom of engine on the left it is run off the timing chain on the 2.4 when you replaced the water outlet did you bleed cooling system ? if not i would try that first also the low cooling light should not come on unless it is low if it is low you may have another leak