Teledyne Continental Motors, Inc.
TM
Maintenance
Inspections
IOF-240 Series Engine Maintenance Manual
7-21
31 August 2007
Change 1
Table 7-3.
Differential Pressure Test Results
Air Discharge Source
Pressure Test Value
Symptoms and
Observations
Recommended Action
Cylinder Differential
Pressure Test reading
above leakage limit.
Normal cylinder
borescope inspection
results.
Continue engine in
service.
Cylinder Differential
Pressure Test reading
below leakage limit.
Normal cylinder
borescope inspection
results.
Fly aircraft at cruise
power
{
and repeat
Cylinder Differential
Pressure Test.
Air discharge into
induction system
Cylinder Differential
Pressure Test reading
below leakage limit after
re-check.
Not applicable
Remove cylinder for
repair.
Cylinder Differential
Pressure Test reading
above leakage limit.
Normal cylinder
borescope inspection
results.
Continue engine in
service.
Cylinder Differential
Pressure Test reading
below leakage limit.
Normal cylinder
borescope inspection
results.
Fly aircraft at cruise
power
{
and repeat
Cylinder Differential
Pressure Test.
Air discharge into
exhaust system
Cylinder Differential
Pressure Test reading
below leakage limit after
re-check.
Not applicable
Remove cylinder for
repair.
Air escaping at spark
plug spot face
Cylinder Differential
Pressure Test readings
not applicable
Dye check of area
reveals cracks.
Remove cylinder for
replacement.
Air discharge at cylinder
head to barrel juncture
or between barrel fins
Cylinder Differential
Pressure Test readings
above leakage limit
First cylinder head fin
above cylinder barrel
wet with oil or baked on
oil residue. See also
latest revision of TCM’s
Service Bulletin SB96-
12 for additional test to
be performed.
Remove cylinder for
replacement.
{
Fly the aircraft at a cruise power setting between 65 and 75 percent power, as specified in the aircraft
Aircraft Flight Manual/Pilots Operating Handbook (AFM/POH), for a duration that will allow the engine oil
and cylinder head temperatures to stabilize, or at least 45 minutes. Perform an additional differential
compression test on the suspect cylinder(s).
|
A sudden increase in oil consumption from the established or normal trend for the engine or an oil
consumption rate that exceeds 1/2 quart (liter) per hour during normal engine operation.