Volkswagen Repair: VW GOLF Overheating, coolant temperature sensor, golf gti 1 8t

Question
I just bought a 2002 Golf Gti 1.8T, suddenly the temperature went up to the red zone and started to beep and a light appeared in the dash.I had to stop every 5 miles to avoid an engine damage.I heard the water pump and has no strange,I also saw the expansion tank boiling water and leaking vapor (i got scared), since that day I don't drive the car anymore and Im planning to do some cheap replacements before I bring the car to auto repair (is all about money that I don't have right now).I'm gonna replace the coolant temperature sensor , then thermostat.I hear similar questions where an expert talked about "vacuum refills", please help me out!

Answer
Hi Antonio;
It sounds like the water pump is done.  When you have the thermostat housing out, you can see the back of the water pump, and more than likely the "impeller" has broken, or just come off of the water pump drive shaft.  You can feel into the water pump housing inside the engine block when the thermostat is out.  The water pump is driven by the timing belt though, and it is an absolute expert type job to replace.  If you plan to do it yourself, be prepared for some frustration, and read up on the procedure at your local library, "Bentley" publication has about the best description.  Read it and then decide if you really want to do it, or save up some cash, and have someone who has done a lot of them do it.  The 1.8T belt, tensioner, water pump, and idler pulley ALL need to be replaced at the same time don't try to save a few bucks just to be disappointed in 10,000 miles when something else breaks.  If all of the parts are replaced at the same time, the repair should last 50,000 or more miles.  Do it right.  The vacuum refill on the cooling system is ABSOLUTELY necessary!!!!!!!  You just can't get all of the air pockets out of the system otherwise.  The aftermarket tools I've seen is called "Air Lift."  Hope this helps, Antonio.  Good luck, man.  Save up a little bit, and then tackle it all at once, you'll be disappointed otherwise.