Diagnosis And Testing - Checking Engine Oil Pressure - Chrysler 300M Service Manual

LH
LUBRICATION (Continued)
(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24 km (15 miles), and
repeat inspection.
(5) If the oil leak source is not positively
identified at this time, proceed with the air leak
detection test method as follows:
• Disconnect the fresh air hose (make-up air) at
the cylinder head cover and plug or cap the nipple on
the cover.
• Remove the PCV valve hose from the cylinder
head cover. Cap or plug the PCV valve nipple on the
cover.
• Attach an air hose with pressure gauge and reg-
ulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kpa (3 PSI) of test pressure.
• Gradually apply air pressure from 1 psi to 2.5
psi maximum while applying soapy water at the sus-
pected source. Adjust the regulator to the suitable
test pressure that provides the best bubbles which
will pinpoint the leak source. If the oil leak is
detected and identified, repair per service manual
procedures.
• If the leakage occurs at the crankshaft rear oil
seal area, refer to the section, Inspection for Rear
Seal Area Leak.
(6) If no leaks are detected, turn off the air supply.
Remove the air hose, all plugs, and caps. Install the
PCV valve and fresh air hose (make-up air). Proceed
to next step.
(7) Clean the oil off the suspect oil leak area using
a suitable solvent. Drive the vehicle at various
speeds approximately 24 km (15 miles). Inspect the
engine for signs of an oil leak by using a black light.
NOTE: If oil leakage is observed at the dipstick tube
to block location; remove the tube, clean and reseal
using Mopar Stud & Bearing Mount (press fit tube
applications only), and for O-ring style tubes,
remove tube and replace the O-ring seal.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the
source of an oil leak in the rear seal area of the
engine, a more involved inspection is necessary. The
following steps should be followed to help pinpoint
the source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery.
(2) Raise the vehicle.
(3) Remove torque converter or clutch housing
cover and inspect rear of block for evidence of oil.
Use a black light to check for the oil leak. If a leak is
present in this area, remove transmission for further
inspection.
(a) Circular spray pattern generally indicates
seal leakage or crankshaft damage.
(b) Where leakage tends to run straight down,
possible causes are a porous block, oil gallery cup
plug, bedplate to cylinder block mating surfaces
and seal bore. See proper repair procedures for
these items.
(4) If no leaks are detected, pressurize the crank-
case as previously described.
CAUTION: Do not exceed 20.6 kPa (3 psi).
(5) If the leak is not detected, very slowly turn the
crankshaft and watch for leakage. If a leak is
detected between the crankshaft and seal while
slowly turning the crankshaft, it is possible the
crankshaft seal surface is damaged. The seal area on
the crankshaft could have minor nicks or scratches
that can be polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft
polishing is necessary to remove minor nicks and
scratches. The crankshaft seal flange is especially
machined to complement the function of the rear oil
seal.
(6) For bubbles that remain steady with shaft
rotation, no further inspection can be done until dis-
assembled.
(7) After the oil leak root cause and appropriate
corrective action have been identified, replace compo-
nent(s) as necessary.
DIAGNOSIS AND TESTING - CHECKING
ENGINE OIL PRESSURE
(1) Remove the oil pressure switch. (Refer to 9 -
ENGINE/LUBRICATION/OIL PRESSURE SENSOR/
SWITCH - REMOVAL)
(2) Install oil pressure test gauge assembly, Spe-
cial Tools C-3292 with 8406 adaptor.
(3) Start engine and monitor gauge readings.
CAUTION: If oil pressure is 0 at idle, Do Not Run
engine at 3000 RPM
(4) Oil Pressure (engine at operating temperature):
Curb Idle 34.5 kPa (5 psi) minimum 3000 RPM
300–724 kPa (45–105 psi).
(5) If oil pressure is 0 at idle. Shut off engine,
check for pressure relief valve stuck open or a
clogged oil pickup screen.
(6) Install oil pressure switch after testing is com-
pleted. (Refer to 9 - ENGINE/LUBRICATION/OIL
PRESSURE SENSOR/SWITCH - INSTALLATION)
ENGINE 9 - 61