Engine Mechanical Repair Day 1

What's the most likely cause of blue smoke from the tailpipe on startup?

• Air pockets in coolant passages

• Worn valve guides

• Worn spark plugs

• A mixture that's too lean

What's the most likely cause of blue smoke from the tailpipe on acceleration?

• Incorrect fuel

• Incorrect coolant

• Worn exhaust seats

• Worn piston rings

What is a compression test used for?

• To determine if there are leaks in a

  combustion chamber

• To determine how much combustion pressure is generated

• To determine exactly where a leak is in a cylinder

• To initiate billable hours

If an engine's dry compression test is below its wear limit on all cylinders, which is a good following test?

• Perform a power balance test

• Perform a running compression test

• Perform a wet compression test

• Perform a "circular swap" of ignition coils

If you perform a compression test without disabling the fuel system, what could occur?

• A "false positive" result

• Incorrect pressures due to presence of raw fuel

• Damage to the catalytic converter

• Longer cranking time for a failed result is required

If there was an 18% increase in compression pressures going from a dry test to a wet test, then:

• This indicates a piston ring problem

• This indicates a valvetrain problem

• This indicates a fuel delivery problem

• This is normal

During a leak-down test you see bubbles in the coolant reservoir. What is the most likely cause?

• Damaged piston ring

• Damaged head gasket

• Damaged exhaust valve

• Damaged intake valve

What does the color of the coolant reservoir cap signify?

• Audi is black, VW is blue

• The country it was produced in

• Its opening (venting) pressure

• It's not significant

During a leak-down test you find 30% leakage on adjacent cylinders. What is the most likely cause?

• Damaged piston ring

• Damaged exhaust valve

• Damaged intake valve

• Cracked head

During a leak-down test you hear loud hissing from the tailpipe. What is the most likely cause?

• Damaged exhaust valve

• Damaged head gasket

• Damaged piston ring

• Damaged intake valve