Overheating and A/C problems

hey guys im new in this forum my names israel. i drive a 01 grand am gt. i got a borla exhaust. 2.5in cutout. 65mm throttle body. DHP pcm. for performance. about a month ago i was driving home on the expressway and my car started to overheat and hit the redline and i shut it off. i also noticed that my ac was not heating up. it would only stay cold and not heat up on the heater. i took it to a mechanic and they told me i needed to rebuild everything. i highly dont believe this guy i think hes trying to milk me for my money. is ther eany solution to whats going on to my vehicle? there are no leaks anywhere that i can see.:shakehead

Welcome to AF !

Sounds like your heater core is clogged, or your water pump is shot and not pumping coolant, thus either would cause the overheating.

Could also be your head gasket or lowr intake blown causing the overheating.. but I'd try tesing/checking a few things before jumping that gun.

How old is your thermostat and coolant ?
How's the coolant level and what color is it ?
Has your lower intake gaskets ever been changed ??
Also does your radiator fans work when the AC is on ?

i have had my gaskets replaced once because it was leaking anti freeze below my throttle body..but there is no leaks... my fans do still turn on with the ac. .and the car still runs fine but it will not cool down at all. but the coolant still gets used up so id otn knwo why it isnt working. i might try replacing my thermostat..i have already replaced it about 1 yr ago. and my gaskets were also a year ago that i had replaced them... other than that.. the car still runs and everything but it will not cool down.

T'stat wont cause the engine to use up the coolant. If the engine is still running smoothly I'd have to think that the head gaskets are good and that your LIM is gone leaking again.