Diagnosis
Valve Train
Block & Assembly
Support Systems
Measurement
100
If a vacuum gauge reading drops steadily to zero as engine speed increases, it usually indicates this type of restriction.
What is a clogged exhaust (restricted catalytic converter)?
100
In an Overhead Cam (OHC) engine, this component is responsible for maintaining constant tension on the timing belt or chain.
What is the tensioner?
100
This component must be removed from the top of the cylinder bore before the pistons can be pushed out during teardown.
What is the carbon ridge?
100
This valve in the oiling system opens if the oil filter becomes completely clogged to prevent engine starvation.
What is the filter bypass valve?
100
This precision tool is used to measure the "out-of-round" condition of a crankshaft journal.
What is an outside micrometer?
200
During a cylinder leakage (leak-down) test, air bubbles appearing in the radiator indicate a failure in this component.
What is the head gasket (or a cracked cylinder head/block)?
200
This is the term for the period when both the intake and exhaust valves are open at the same time.
What is valve overlap?
200
This type of main bearing is designed to control the fore-and-aft (end play) movement of the crankshaft.
What is a thrust bearing?
200
A cooling system pressure tester can be used to find external leaks and to test the operation of this specific component.
What is the radiator cap?
200
his plastic material is flattened between a journal and a bearing to check for oil clearance.
What is Plastigage?
300
Blue smoke emitting from the exhaust specifically during a cold start-up usually points to this mechanical failure.
What are worn valve stem seals?
300
An engine that sustains internal damage if the timing belt breaks is known by this classification.
What is an interference engine?
300
When installing piston rings, the gaps must be positioned in this way to prevent "blow-by."
What is staggered (or offset/clocker)?
300
This is the most common cause of "milky" looking engine oil.
What is coolant contamination (internal leak)?
300
This tool is used in conjunction with a telescoping gauge to determine the actual diameter of a cylinder bore.
What is an outside micrometer?
400
A "cranking compression test" is being performed; if adding a tablespoon of oil to a low cylinder causes the pressure to rise significantly, this part is likely worn.
What are the piston rings?
400
An engine that sustains internal damage if the timing belt breaks is known by this classification.
What is an interference engine?
400
This term refers to the difference between the diameter of the cylinder at the top and the diameter at the bottom.
What is cylinder taper?
400
A technician finds high oil pressure at high RPMs but normal pressure at idle; this internal oil pump component is likely stuck closed.
What is the pressure relief valve?
400
When checking a cylinder head for warpage, a technician uses a precision straightedge and this other tool.
What is a feeler gauge?
500
This diagnostic tool is used to detect combustion gases (CO2) present in the engine's cooling system
What is a chemical block tester (combustion leak detector)?
500
If the "installed height" of a valve spring is too high, it will result in this condition, potentially causing valve float.
What is low spring pressure (low seat pressure)?
500
This finishing process is performed on cylinder walls to create a cross-hatch pattern that helps retain oil for ring lubrication.
What is honing?
500
Modern engines often use this "fail-safe" cooling strategy, which alternates firing cylinders to pump air and cool the engine if it overheats.
What is Strategy-Based Cooling (or Limp Home Mode)?
500
This measurement represents the distance the piston sits above or below the block deck surface at TDC.
What is piston deck height?