Cooling system my fan relay went out and i fixed it, but it still is overheating. I dont have any idea how to check the thermostat or water pump. where do i start?

Water pump bad

Check that the fan is working properly, whether it is electric or a belt driven fan. A car will overheat if the fan doesn't function as originally designed.

CHECK COOLANT LEVEL MOST NEWER VECHICLE DONT HAVE RADIATOR CAP YOU HAVE TO POUR COOLANT IN THE COOLANT OVERFLOW JUG THE COOLANT WILL GO TO RADIATOR. IF THE COOLANT OVERFLOW JUG EMPTY ADD COOLANT UNTIL COOLANT LEVEL STOP DROPPING AT STAY AT FULL COLD MARK.IF COOLANT OKAY,NEED TO REPLACE THERMOSTAT AND COOLANT OVERFLOW JUG PRESSURE CAP. IF ALL BEEN DONE. MOST OF THE TIME WHEN CAR OVERHEATING WHILE MOVING. RADIATOR CORES STOPPED UP OR RADIATOR GRILLE DIRTY OR RESRICTED.ENGINE BLOCK COOLANT PASSAGES CLOGGED AND HEATER CORE CLOGGED.CHECK WATER PUMP SEE IF WATER PUMP WEEP HOLE LEAKING IF SO REPLACE WATER PUMP.IF ENGINE OVERHEATING AT A LONG TRAFFIC LINE ENGINE COOLING FANS NOT RUNNING EITHER COOLING FANS FUSE AND RELAYS BAD.OR ENGINE COOLANT TEMPERATURE BAD. THE ENGINE COOLANT TEMPERATURE SENSOR TURNS ON COOLING FANS AT A CERTAIN TEMPERATURE IF SENSOR BAD FANS WONT TURN ON. MAKE SURE YOU HAVE 50 /50 MIXTURE OF COOLANT AND WATER IN COOLING SYSTEM.

REPLACE THE THERMOSTAT AND RADIATOR PRESSURE CAP.IF COOLANT LOW, ADD MORE COOLANT THROUGH COOLANT OVERFLOW UNTIL COOLANT LEVEL IN THE COOLANT OVERFLOW STAY AT FULL COLD MARK.REASON POUR COOLANT THROUGH COOLANT OVERFLOW MOST GM CARS DONT HAVE RADIATOR CAP.WHEN YOU GET COOLANT LEVEL OKAY, CRANK CAR LET IT IDLE UNTIL ENGINE GET HOT BUILD UP PRESSURE THEN TURN OFF CAR.CHECK FOR COOLANTS LEAKS AT THE RADIATOR HOSES,CHECK FOR LEAKS AT THE RADIATOR, CHECK FOR LEAKS AT WATER PUMP WEEP HOLE IF YOU SEE COOLANT LEAKING FROM WEEP HOLE REPLACE WATER PUMP. IF CAR OVERHEATING WHILE IDLING YOUR COOLING FANS NOT WORKING CHECK COOLING FANS FUSE AND RELAYS.IF FUSE AND RELAYS OKAY THE ENGINECOOLANT TEMPERATURE SENSOR BAD.

that would be coolant or anti freeze,but it dont over heating it helps keep the cooling system rust free and helps prevent overheating but it dont keep it from overheating,if your overheating there is a problem you need to deal with,check the water level,check the thermostat,are the fans turning on,is there signs of leaking around the water pump?

Could be both your water pump and thermostat are faulty. Start with the simple and replace the thermostat and also did the engine over heat while you were stopped or in stop and go traffic, if you were then you may have a blown fuse or bad cooling fan relay that needs to be addressed. Check to make sure your Cooling fan is working, you can test this buy turning on your A/C on full and the fan should come one the same time your A/C clutch activates. If the fan does not function, inspect the electrical system to the cooling fans and replace the thermostat to ensure there will not be any issues in the summer time. Thermostat are know to go bad when they are over heated.
Thank you for using FIxya and good luck

Removal of the thermostat from the cooling system is not a good idea. This upsets the coolant flow rate in the system, and that can cause the engine to overheat, even when no other problem with the cooling system exists.

Try to identify the cause of the overheating.

Ensure that engine tune, or other engine mechanical fault condition is not the cause of the overheating, then go through the checklist following:-

1) Check engine cooling fan/s are operating as required when engine temp rises above cut-in threshold - check fan control relay is ok,
2) Check for collapsing radiator hose on suction side of water-pump when motor revs raised above idle.
3) Check coolant reservoir pressure cap is serviceable,
4) Check coolant system is properly filled - carry out any bleed off procedure specified to clear any air locks- (ensure heater core coolant flow is turned on).
5) Check for combustion gas bubbles in the coolant reservoir while the motor is running - this indicates a blown head gasket. If in doubt, take it to a radiator shop and ask for a combustion gas check on your radiator.
6) Check condition of radiator core:-
i) for blockage of air flow to (bugs/grass etc),
ii) for core internal blockage to coolant flow,

If all above ok, replace the thermostat again (also ensure it is not installed upside down) - faulty new thermostats are not unheard of.

The thermostat is bolted into the bottom of the water pump, the lower radiator hose connects to a cover that holds the thermostat to the water pump.

the thermostat can be difficult to get at because the AC and power steering pump are all bolted on top of the water pump,

Your problem may not be a bad thermostat.
I would also check:

1) water pump, some of the vw pumps are poorly made & tend to go bad.

2) fans belts, it can be tricky to get the right tension on these belts due to a badly designed tensioner system on the power steering & water pump belt.

3) hoses, radiator, coolant tank,. the radiators and coolant tank tend to leak when they get old, the plastic cracks or the rubber seals go bad.
Also check the electrical system controlling the engine cooling fans. there are sensors and relays that can go bad.
I have owned 8 vw's most of the major problems with these cars was due to electical problems.

4) Engine problems such as a blown head gaskets, or ignition timing problems can cause overheating. luckily VW engines usually don't have these problems, unlike other companies 4 cylinder engines (the Dodge Neons for example)

hello, have you ran a scan tool on it yet to see if its not your coolant temp sensor or other temp sensor if you don't own one you can have any place like auto zone run one for you for free you'll have more of a idea of whats wrong even if your cooling fan is at fault it'll let you know. when your chevy is at idol if the cooling fan is'nt kicking on then that's a good starting point,also check to make sure your anti freeze is'nt low and easy but over looked problem and your anti freeze cap could be bad and wont force the right amount to pressure through the cooling system also make sure you dont have air in your system when you changed the thermostat did you bleed the system through the bleeder valve mounted on the coolint system.and make sure your drive belt has proper tension even though you replaced the pump the drive belt has to be in good condition it drives the pump.also check your cooling fan fuse and the relay for it.

your fans need replacing try hooking them up straight to battery to check if they spin fast its not the fans but the wiring.