I had the same overheating problem because I only had one fan on my radiator. The small gap created by my front mount and the radiator was causing air to escape underneath the car instead of straight to the radiator. I built a plastic shroud for the gap and bought a slimline fan and have had no problems with overheating since then. If the overheating is gradual, this will fix your problem. If the temperature is drastically changing, replace your thermostat. good luck...