
DIAGNOSIS AND TESTINGÐLUBRICATION
CONDITION POSSIBLE CAUSES CORRECTION
OIL LEAKS 1. Gaskets and O-Rings. 1.
(a) Misaligned or damaged. (a) Replace as necessary.
(b) Loose fasteners, broken or
porous metal parts.(b) Tighten fasteners, Repair or
replace metal parts.
2. Crankshaft rear seal 2. Replace as necessary.
3. Crankshaft seal flange.
Scratched, nicked or grooved.3. Polish or replace crankshaft.
4. Oil pan flange cracked. 4. Replace oil pan.
5. Timing chain cover seal,
damaged or misaligned.5. Replace seal.
6. Scratched or damaged vibration
damper hub.6. Polish or replace damper.
OIL PRESSURE DROP 1. Low oil level. 1. Check and correct oil level.
2. Faulty oil pressure sending unit. 2. Replace sending unit.
3. Low oil pressure. 3. Check pump and bearing
clearance.
4. Clogged oil filter. 4. Replace oil filter.
5. Worn oil pump. 5. Replace as necessary.
6. Thin or diluted oil. 6. Change oil and filter.
7. Excessive bearing clearance. 7. Replace as necessary.
8. Oil pump relief valve stuck. 8. Clean or replace relief valve.
9. Oil pump suction tube loose or
damaged.9. Replace as necessary.
OIL PUMPING AT RINGS; SPARK
PLUGS FOULING1. Worn or damaged rings. 1. Hone cylinder bores and replace
rings.
2. Carbon in oil ring slots. 2. Replace rings.
3. Incorrect ring size installed. 3. Replace rings.
4. Worn valve guides. 4. Ream guides and replace valves.
5. Leaking intake gasket. 5. Replace intake gaskets.
6. Leaking valve guide seals. 6. Replace valve guide seals.
9 - 66 ENGINE 5.2LBR/BE
ENGINE 5.2L (Continued)

DIAGNOSIS AND TESTINGÐCYLINDER
COMPRESSION PRESSURE
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.
Otherwise, the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Clean the spark plug recesses with compressed
air.
(2) Remove the spark plugs (Refer to 8 - ELEC-
TRICAL/IGNITION CONTROL/SPARK PLUG -
REMOVAL).
(3) Secure the throttle in the wide-open position.
(4) Disconnect the ignition coil.
(5) Insert a compression pressure gauge and rotate
the engine with the engine starter motor for three
revolutions.
(6) Record the compression pressure on the third
revolution. Continue the test for the remaining cylin-
ders.
(Refer to 9 - ENGINE - SPECIFICATIONS) for the
correct engine compression pressures.
DIAGNOSIS AND TESTINGÐCYLINDER
COMBUSTION PRESSURE LEAKAGE
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
²Exhaust and intake valve leaks (improper seat-
ing)
²Leaks between adjacent cylinders or into water
jacket²Any causes for combustion/compression pressure
loss
WARNING: DO NOT REMOVE THE RADIATOR CAP
WITH THE SYSTEM HOT AND UNDER PRESSURE.
SERIOUS BURNS FROM HOT COOLANT CAN
OCCUR.
Check the coolant level and fill as required. DO
NOT install the radiator cap.
Start and operate the engine until it attains nor-
mal operating temperature, then turn OFF the
engine.
Remove the spark plugs.
Remove the oil filler cap.
Remove the air cleaner.
Calibrate the tester according to the manufactur-
er's instructions. The shop air source for testing
should maintain 483 kPa (70 psi) minimum, 1,379
kPa (200 psi) maximum and 552 kPa (80 psi) recom-
mended.
Perform the test procedure on each cylinder accord-
ing to the tester manufacturer's instructions. While
testing, listen for pressurized air escaping through
the throttle body, tailpipe or oil filler cap opening.
Check for bubbles in the radiator coolant.
All gauge pressure indications should be equal,
with no more than 25% leakage.
FOR EXAMPLE:At 552 kPa (80 psi) input pres-
sure, a minimum of 414 kPa (60 psi) should be main-
tained in the cylinder.
Refer to CYLINDER COMBUSTION PRESSURE
LEAKAGE DIAGNOSIS CHART below
CYLINDER COMBUSTION PRESSURE LEAKAGE DIAGNOSIS CHART
CONDITION POSSIBLE CAUSE CORRECTION
AIR ESCAPES THROUGH
THROTTLE BODYIntake valve bent, burnt, or not
seated properlyInspect valve and valve seat.
Reface or replace, as necessary
AIR ESCAPES THROUGH
TAILPIPEExhaust valve bent, burnt, or not
seated properlyInspect valve and valve seat.
Reface or replace, as necessary
AIR ESCAPES THROUGH
RADIATORHead gasket leaking or cracked
cylinder head or blockRemove cylinder head and inspect.
Replace defective part
MORE THAN 50% LEAKAGE
FROM ADJACENT CYLINDERSHead gasket leaking or crack in
cylinder head or block between
adjacent cylindersRemove cylinder head and inspect.
Replace gasket, head, or block as
necessary
MORE THAN 25% LEAKAGE AND
AIR ESCAPES THROUGH OIL
FILLER CAP OPENING ONLYStuck or broken piston rings;
cracked piston; worn rings and/or
cylinder wallInspect for broken rings or piston.
Measure ring gap and cylinder
diameter, taper and out-of-round.
Replace defective part as necessary
BR/BEENGINE 5.2L 9 - 67
ENGINE 5.2L (Continued)

SPECIFICATIONS
5.2L ENGINE
ENGINE SPECIFICATIONS
DESCRIPTION SPECIFICATION
GENERAL SPECIFICATIONS
Engine Type 90É V-8 OHV
Bore and Stroke 99.3 x 84.0 mm
(3.91 x 3.31 in.)
Displacement 5.2L
(318 c.i.)
Compression Ratio 9.1:1
Firing Order 1±8±4±3±6±5±7±2
Lubrication Pressure FeedÐ
Full Flow Filtration
Cooling System Liquid CooledÐ
Forced Circulation
Cylinder Block Cast Iron
Crankshaft Nodular Iron
Cylinder Head Cast Iron
Combustion Chambers Wedge-High Swirl
Valve shrouding
Camshaft Nodular Cast Iron
Pistons Aluminum Alloy w/strut
Connecting Rods Forged Steel
Cylinder Compression 689.5 kPa
Pressure (Min.) (100 psi)
CAMSHAFT
Bearing Diameter
No. 1 50.800 ± 50.825 mm
(2.000 ± 2.001 in.)
No. 2 50.394 ± 50.419 mm
(1.984 ± 1.985 in.)
No. 3 50.013 ± 50.038 mm
(1.969 ± 1.970 in.)
No. 4 49.606 ± 49.632 mm
(1.953 ± 1.954 in.)
DESCRIPTION SPECIFICATION
No. 5 39.688 ± 39.713 mm
(1.5625 ± 1.5635 in.)
Bearing Journal Diameter
No. 1 50.749 ± 50.775 mm
(1.998 ± 1.999 in.)
No. 2 50.343 ± 50.368 mm
(1.982 ± 1.983 in.)
No. 3 49.962 ± 49.987 mm
(1.967 ± 1.968 in.)
No. 4 49.555 ± 49.581 mm
(1.951 ± 1.952 in.)
No. 5 39.637 ± 39.662 mm
(1.5605 ± 1.5615 in.)
Bearing to Journal
Clearance
Standard 0.0254 ± 0.0762 mm
(0.001 ± 0.003 in.)
Service Limit 0.127 mm
(0.005 in.)
End Play 0.051 ± 0.254 mm
(0.002 ± 0.010 in.)
CONNECTING RODS
Piston Pin bore Diameter 24.966 ± 24.978 mm
(0.9829 ± 0.9834 in.)
Side Clearance 0.152 ± 0.356 mm
(0.006 ± 0.014 in.)
CRANKSHAFT
Rod Journal
Diameter 53.950 ± 53.975 mm
(2.124 ± 2.125 in.)
Out of Round (Max.) 0.0254 mm
(0.001 in.)
Taper (Max.) 0.0254 mm
(0.001 in.)
Bearing Clearance 0.013 ± 0.056 mm
(0.0005 ± 0.0022 in.)
Service Limit 0.0762 mm
(0.003 in.)
9 - 72 ENGINE 5.2LBR/BE
ENGINE 5.2L (Continued)

DESCRIPTION SPECIFICATION
Main Bearing Journal
Diameter 63.487 ± 63.513 mm
(2.4995 ± 2.5005in.)
Out of Round (Max.) 0.127 mm
(0.001 in.)
Taper (Max.) 0.0254 mm
(0.001 in.)
Bearing Clearance
(#1 Journal) 0.013 ± 0.038 mm
(0.0005 ± 0.0015 in.)
(#2-5 Journals) 0.013 ± 0.051 mm
(0.0005 ± 0.002 in.)
Service Limit
(#1 Journal) 0.0381 mm
(0.0015 in.)
(#2-5 Journals) 0.064 mm
(0.0025 in.)
End Play 0.051 ± 0.178 mm
(0.002 ± 0.007 in.)
Service Limit 0.254 mm
(0.010 in.)
CYLINDER BLOCK
Cylinder Bore
Diameter 99.308 ± 99.371 mm
(3.9098 ± 3.9122 in.)
Out of Round (Max.) 0.025 mm
(0.001 in.)
Taper (Max.) 0.025 mm
(0.001 in.)
Oversize Limit 1.016 mm
(0.040 in.)
Lifter Bore Diameter 22.99 ± 23.01 mm
(0.9051 ± 0.9059 in.)
Distributor Drive Bushing
(Press Fit)
Bushing to Bore
Interference0.0127 ± 0.3556 mm
(0.0005 ± 0.0140 in.)
Shaft to Bushing
Clearance0.0178 ± 0.0686 mm
(0.0007 ± 0.0027 in.)DESCRIPTION SPECIFICATION
CYLINDER HEAD
Valve Seat
Angle 44.25É ± 44.75É
Runout (Max.) 0.0762 mm
(0.003 in.)
Width (Finish)
Intake 1.016 ± 1.524 mm
(0.040 ± 0.060 in.)
Exhaust 1.524 ± 2.032 mm
(0.060 ± 0.080 in.)
VA LV E S
Face Angle 43.25É ± 43.75É
Head Diameter
Intake 48.666 mm
(1.916 in.)
Exhaust 41.250 mm
(1.624 in.)
Length (Overall)
Intake 124.28 ± 125.92 mm
(4.893 ± 4.918 in.)
Exhaust 124.64 ± 125.27 mm
(4.907 ± 4.932 in.)
Lift (@ zero lash) 10.973 mm
(0.432 in.)
Stem Diameter 7.899 ± 7.925 mm
(0.311 ± 0.312 in.)
Guide Bore 7.950 ± 7.976 mm
(0.313 ± 0.314 on.)
Stem to Guide Clearance 0.0254 ± 0.0762 mm
(0.001 ± 0.003 in.)
Service Limit (rocking
method)0.4318 mm
(0.017 in.)
VALVE SPRINGS
Free Length 49.962 mm
(1.967 in.)
Spring Tension
BR/BEENGINE 5.2L 9 - 73
ENGINE 5.2L (Continued)

DESCRIPTION SPECIFICATION
valve closed 378 N @ 41.66 mm
(85 lbs. @ 1.64 in.)
valve open 890 N @ 30.89 mm
(200 lbs. @ 1.212 in.)
Number of Coils 6.5
Installed Height 41.66 mm
(1.64 in.)
Wire Diameter 4.50 mm
(0.177 in.)
HYDRAULIC TAPPETS
Body Diameter 22.949 ± 22.962 mm
(0.9035 ± 0.9040 in.)
Clearance (to bore) 0.0279 ± 0.0610 mm
(0.0011 ± 0.0024 in.)
Dry Lash 1.524 ± 5.334 mm
(0.060 ± 0.210 in.)
Push Rod Length 175.64 ± 176.15 mm
(6.915 ± 6.935 in.)
OIL PRESSURE
Curb Idle (Min.*) 41.4 kPa (6 psi)
@ 3000 rpm 207 ± 552 kPa
(30 ± 80 psi)
Oil Pressure Bypass
Valve
Setting 62 ± 103 kPa
(9 ± 15 psi)
Switch Actuating
Pressure34.5 ± 48.3 kPa
(5 ± 7 psi)
* If oil pressure is zero at curb idle, DO NOT RUN
ENGINE.
OIL PUMP
Clearance over Rotors
(Max.)0.0381 mm
(0.0015 in.)DESCRIPTION SPECIFICATION
Inner Rotor Thickness
(Min.)20.955 mm
(0.825 in.)
Outer Rotor Clearance
(Max.)0.3556 mm
(0.014 in.)
Outer Rotor Diameter
(Min.)62.7126 mm
(2.469 in.)
Outer Rotor Thickness
(Min.)20.955 mm
(0.825 in.)
Tip Clearance between
Rotors
(Max.) 0.2032 mm
(0.008 in.)
PISTONS
Clearance at Top of Skirt 0.013 ± 0.038 mm
(0.0005 ± 0.0015 in.)
Land Clearance (Diam.) 0.635 ± 1.016 mm
(0.025 ± 0.040 in.)
Piston Length 86.360 mm (3.40 in.)
Piston Ring Groove
Depth
Groove #1&2 4.572 ± 4.826 mm
(0.180 ± 0.190 in.)
Groove #3 3.810 ± 4.064 mm
(0.150 ± 0.160 in.)
Weight 592.6 ± 596.6 grams
(20.90 ± 21.04 oz.)
PISTON PIN
Clearance in Piston 0.00635 ± 0.01905 mm
(0.00025 ± 0.00075 in.)
Diameter 24.996 ± 25.001 mm
(0.9841 ± 0.9843 in.)
End Play NONE
Length 75.946 ± 76.454 mm
(2.990 ± 3.010 in.)
9 - 74 ENGINE 5.2LBR/BE
ENGINE 5.2L (Continued)

DESCRIPTION SPECIFICATION
PISTON RINGS
Ring Gap
Compression Rings 0.254 ± 0.508 mm
(0.010 ± 0.020 in.)
Oil Control (Steel Rails) 0.254 ± 1.270 mm
(0.010 ± 0.050 in.)
Ring Side Clearance
Compression Rings 0.038 ± 0.076 mm
(0.0015 ± 0.0030 in.)
Oil Ring (Steel Rails) 0.06 ± 0.21 mm
(0.002 ± 0.008 in.)
Ring Width
Compression rings 1.971 ± 1.989 mm
(0.0776 ± 0.0783 in.)
Oil Ring (Steel Rails) ±
Max.3.848 ± 3.975 mm
(0.1515 ± 0.1565 in.)
VALVE TIMING
Exhaust Valve
Closes (ATDC) 21É
Opens (BBDC) 60É
Duration 264É
Intake Valve
Closes (ATDC) 61É
Opens (BBDC) 10É
Duration 250É
Valve Overlap 31ÉOVERSIZE AND UNDERSIZE ENGINE
COMPONENT MARKINGS CHART
U/S-O/S Item Identification Identification
Location
U/S Rod/ R or M R-1-4
ect.Milled flat on
No.8
.0254
mmMain (indicating No.
1crankshaft
(0.001
in.)Journal and 4
connectingcounterweight.
rod journal)
and/or
M-2-3 ect.
(indicating No.
2
and 3 main
bearing
journal)
O/S HydraulicLDiamond-
shaped
.2032
mmTappets stamp top pad
-
(.008 in.) front of engine
and flat
ground
on outside
surface of
each
O/S tappet
bore.
O/S Valve X Milled pad
.127 mm Stems adjacent to
two
(.005 in.) tapped holes
(3/8 in.) on
each
end of
cylinder
head.
BR/BEENGINE 5.2L 9 - 75
ENGINE 5.2L (Continued)

SPECIAL TOOLS
5.2L ENGINE
Oil Pressure Gauge C-3292
Engine Support Fixture C-3487±A
Valve Spring Compressor MD-998772±A
Adaptor 6633
Adaptor 6716A
Valve Guide Sleeve C-3973
Dial Indicator C-3339
Puller C-3688
Puller 1026
Crankshaft Damper Removal Insert 8513
BR/BEENGINE 5.2L 9 - 77
ENGINE 5.2L (Continued)

CYLINDER HEAD
DESCRIPTIONÐCYLINDER HEAD
The cast iron cylinder heads (Fig. 4) are mounted
to the cylinder block using ten bolts. The spark plugs
are located in the peak of the wedge between the
valves.
DESCRIPTIONÐCYLINDER COVER GASKET
The cylinder head cover gasket (Fig. 5) is a steel-
backed silicone gasket, designed for long life usage.
OPERATIONÐCYLINDER HEAD
The cylinder head closes the combustion chamber
allowing the pistons to compress the air fuel mixture
to the correct ratio for ignition. The valves located in
the cylinder head open and close to either allow clean
air into the combustion chamber or to allow theexhaust gases out, depending on the stroke of the
engine.
OPERATION
The steel-backed silicone gasket is designed to seal
the cylinder head cover for long periods of time
through extensive heat and cold, without failure. The
gasket is designed to be reusable.
DIAGNOSIS AND TESTINGÐCYLINDER HEAD
GASKET FAILURE
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
²Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
²Loss of engine power
²Engine misfiring
²Poor fuel economy
²Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
²Engine overheating
²Loss of coolant
²Excessive steam (white smoke) emitting from
exhaust
²Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders, follow the proce-
dures in Cylinder Compression Pressure Test in this
section. An engine cylinder head gasket leaking
between adjacent cylinders will result in approxi-
mately a 50±70% reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING WITH COOLANT PRES-
SURE CAP REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure
cap. Start the engine and allow it to warm up until
thermostat opens.
If a large combustion/compression pressure leak
exists, bubbles will be visible in the coolant.
Fig. 4 Cylinder Head AssemblyÐV-8 Gas Engines
1 - EXHAUST VALVE
2 - SPARK PLUGS
3 - EXHAUST VALVES
4 - SPARK PLUGS
5 - EXHAUST VALVE
6 - INTAKE VALVES
7 - INTAKE VALVES
Fig. 5 Cylinder Head Cover Gasket V-8 Gas Engines
1 - CYLINDER HEAD COVER GASKET
BR/BEENGINE 5.2L 9 - 79