When im driving for about 5 min i start to hear this loud humming like if tha ac jus turned one then then car start to slowly overheat then slowly goes down and goes away as i keep driving. but when tha heater is on it doesnt happen. need help on whats goin on plzzzzz

sounds like hte thermostat is sticking.... replace it. figure 10-15 bucks

+1 on the thermostat. It's a cheap easy fix.

thanks i'll see what happens

I am facing the same problem. I am taking my car to local mechanic. this weekend.

post your problem in the LS forum! State year, engine, and symptoms!