These two Cummins 600 hp diesel engines were experiencing temperatures of over 200°F! Upon further inspection, it was noted that the heat exchangers were fouled with scale and marine growth. RYDLYME Marine was then added to the heat exchanger top with the bottom plugged. As the solution dissolved the water scale and marine growth, more RYDLYME Marine was added to the heat exchanger. After several hours of static cleaning, the water scale was completely dissolved! Temperatures are now at a respectable 168°F!