Ch 11 – Engine Coolant Systems Review Questions 1. Which type of diesel engine coolant is regarded as potentially the most harmful? EG (ETHYLENE GLYCOL) 2. Which of the following cooling media would transfer heat most efficiently? PURE WATER 3. Wet liner cavitation is caused by: VAPOR BUBBLE COLLAPSE 4. The cooling system hoses on a engine collapse when the unit is left parked overnight, which of the following is likely cause? A DEFECTIVE RADIATOR CAP 5. Which would be the warmest portion of a typical downflow type radiator when the engine is at operating temperature? THE TOP TANK 6. If a radiator cap pressure valve fails to seal which of the following would be the likely outcome? HIGHER HC EMISSIONS 7. The temperature rating of a thermatic viscous fan hub ia a nominal hub is a nominal 155F (68c) at approximately what equivalent coolant temperature will this produce minumum slip drive as temperature rise? 165 F (74*c) 8. In a typical diesel powered highway truck at operating temperature which of the following should be true? COOLANT TEMPERATURE RUNS COOLER THAN LUBE OIL TEMPERATURE 9. Which of the following properly describes the operating principle of a typical coolant pump on a highway diesel engine? CENTRIFUGAL 10. Which of the following controls the drive efficiency of a thermatic viscous drive fan hub? BIMETAL STRIP