Overheating, Signs of Exhaust in Coolant, but None
My car overheats on the freeway after about 20-30
minutes, especially in stop and go traffic. I see
signs of exhaust in the radiator (when rad cap is
off and car is running, bubbles come up. Steam
comes out once it gets hot. Fluid comes out when
car revved). However, it just passed a block test
with flying colors (fluid that detects exhaust stayed
dark blue, no hint of green or yellow). What other
issue could cause those same symptoms? Any
help would be greatly appreciated. Oh, and I just
changed the thermostat. No difference.
