Question 477Motor Plants - Assistant Engineer

The correct answer is C) air charge density decreases. When the cooling water flow through the aftercooler is interrupted, the air charge entering the engine will be less dense. This is because the aftercooler is responsible for cooling the compressed air from the turbocharger, which increases the air density. With the cooling water flow interrupted, the air will not be sufficiently cooled, resulting in a decrease in air charge density. This lower air density leads to a reduction in the power output of the turbocharged diesel engine. The other options are incorrect because a stalled turbocharger (A) would not be the direct cause, an increase in exhaust pressure (B) is not the primary effect, and an increased scavenge effect (D) is not relevant to the issue of cooling water flow interruption.