It sounds like the cooling fans are randomly toggling between low (or off) and high speed. The first thing that comes to mind is a faulty high-speed fan relay. Other possibilities include a faulty powertrain control module or refrigerant pressure switch.
1. Do the fans do this only when the climate control is on?
2. How about with the climate control is off and the engine is idled long enough for the temperature to rise to the point where the fans would normally turn on high and stay on for several seconds or more?
1. Do the fans do this only when the climate control is on?
2. How about with the climate control is off and the engine is idled long enough for the temperature to rise to the point where the fans would normally turn on high and stay on for several seconds or more?