Exam 14: Cooling System

_____ in the thermostat expands to cause it to open.

What instrument can determine the coolant's conductivity?

Technician A says a temperature-controlled fan clutch is controlled by a spring that shrinks when it is heated and expands when it is cooled. Technician B says that electric fans found on many late model cars sometimes run after the engine is shut off. Who is correct?

When measuring the voltage of coolant, what is the limit before the system should be flushed out?

Why is ethylene glycol coolant dangerous to animals?

A transmission heat exchanger has failed. Technician A says that if the engine is running, oil will flow from the transmission to the radiator. Technician B says that when the engine is off, coolant will flow into the transmission. Who is right?

Technician A says that a fan is not necessary at freeway speeds. Technician B says that the fan is supposed to push air through the radiator. Who is right?

Technician A says that older radiator cores are made of copper and brass. Technician B says that newer radiator cores are usually made of aluminum and have plastic tanks. Who is right?

Technician A says that installing a thermostat with a lower temperature rating will help an engine run cooler in hot weather. Technician B says that a stuck-closed thermostat can cause a computer-controlled fuel system to run rich when the engine is cold. Who is right?

Technician A says aluminum oxide forms if the coolant becomes too diluted with water. Technician B says the thermostat on all engines remains closed until its predetermined opening point. Who is correct?

Technician A says that a vehicle that overheats only on the freeway probably has a stuck-closed thermostat. Technician B says that the thermostat can be left out of the engine with no ill effects. Who is right?

Technician A says borax included in an SCA package is a buffer and acid neutralizer. Technician B says phosphate is added to antifreeze to protect aluminum parts in the cooling system. Who is correct?

All of the following are examples of the cause of electrolysis, EXCEPT _____.

Automotive coolant is a combination of ethylene glycol and ____

Technician A says that when replacing a thermostat the temperature sensing bulb faces out of the block. Technician B says that engines with aluminum heads should use antifreeze with special (silicate) additives. Who is right?

_____ is the name of one type of coolant additive that protects aluminum.

If a flushing procedure is not entirely effective in correcting an engine with thermoplastic seizure, what must be done?

Technician A says that the lower radiator hose fails most often. Technician B says that 100% coolant provides better cooling than a mixture of coolant and water. Who is right?

Cavitation means air bubbles form in the coolant and then collapse.

What is it called when an electrical current develops between two dissimilar types of metal in the cooling system?