1997 MAZDA MIATA engine oil

Fitting Pistons
1. Ensure pistons are not scored or damaged. Measure piston diameter on piston skirt at 90-degree angle
from piston pin, .65" (16.5 mm) below lowest ring groove. See PISTONS, PINS & RINGS
under
ENGINE SPECIFICATIONS.
2. Check piston-to-cylinder wall clearance in 3 different vertical places of piston travel. If clearance is not
within specification, re-bore cylinders to fit oversize pistons. Using NEW piston rings, measure piston
ring side clearance around entire piston circumference. If clearance is not within specification, replace
piston. See PISTONS, PINS & RINGS
.
Piston Rings
1. If ring end gap and side clearance are not within specification, replace piston and/or rings as necessary.
See PISTONS, PINS & RINGS
under ENGINE SPECIFICATIONS.
2. Install oil ring spacer. Ensure ends DO NOT overlap. See Fig. 19
. Upper and lower rails are the same
and are interchangeable. In stall rails, ensuring rails are expanded by spacer tangs (oil rings when
assembled should rotate freely). Install rings No. 1 (top) and No. 2 (second) with "R" mark toward top of
piston. Ensure ring end gaps are properly positioned around piston. See Fig. 20
.
Fig. 19: Identifying Oil Rings
NOTE: Pistons and rings are available in .010" (.25 mm) and .020" (.50 mm) oversize.

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
Microsoft
Sunday, July 05, 2009 1:55:15 PMPage 29 © 2005 Mitchell Repair Information Company, LLC.

Courtesy of MAZDA MOTORS CORP.
Fig. 20: Identifying Piston Rings & Positioning Ring End Gaps

Courtesy of MAZDA MOTORS CORP.
Crankshaft & Main Bearings
1. Check crankshaft connecting rod journals for wear, out-of-round, taper and undersize. Machine or replace
crankshaft and/or bearings as necessary. See CRANKSHAFT, MAIN & CONNECTING ROD
BEARINGS under ENGINE SPECIFICATIONS.
2. Before removing main cap, measure and record crankshaft end play by prying crankshaft forward, then
rearward. Using Plastigage method, measure and record main bearing oil clearance. Remove crankshaft.
Measure and record each main journal diameter in 2 places. See CRANKSHAFT, MAIN &
CONNECTING ROD BEARINGS under ENGINE SPECIFICATIONS.

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
Microsoft
Sunday, July 05, 2009 1:55:15 PMPage 30 © 2005 Mitchell Repair Information Company, LLC.

3. Install main bearing caps with square mark facing front of engine. Tighten main bearing cap bolts in 2-3
step, working outward from center bearing. Tighten bolts to specification. See TORQUE
SPECIFICATIONS . Thrust Bearing - Install thrust bearing before installing crankshaft. Check
crankshaft end play with crankshaft bearings and caps installed, but without connecting rods attached to
crankshaft. DO NOT turn crankshaft until bearings are lubricated. If crankshaft end play exceeds
specification, grind crankshaft and replace thrust bearings with oversize thrust bearings, or replace
crankshaft and thrust bearings. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS

under ENGINE SPECIFICATIONS.
Cylinder Block
Check cylinder bore out-of-round, taper, ridge and piston-to-cylinder bore clearance. Check head gasket surface
for warpage. If warpage is not within specification, machine or replace cylinder block as necessary. See
CYLINDER BLOCK
under ENGINE SPECIFICATIONS. Remove, clean and install oil jets for piston oil
spraying.
ENGINE OILING
ENGINE LUBRICATION SYSTEM
NOTE: See cross-sectional view of engine oil circuit. See Fig. 21
.

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
Microsoft
Sunday, July 05, 2009 1:55:15 PMPage 31 © 2005 Mitchell Repair Information Company, LLC.

Fig. 21: Cross-Sectional View Of Engine Oil Circuit
Courtesy of MAZDA MOTORS CORP.
Crankcase Capacity
See ENGINE OIL CRANKCASE CAPACITY .
Oil Pressure
With engine at operating temperature, oil pressure should be 15-28 psi (1.0-2.0 kg/cm2 ) at 1000 RPM, and 43-
57 psi(3.0-4.0 kg/cm
2 ) at 3000 RPM.
Oil Pressure Relief Valve
Pressure relief valve opening pressure is 50-64 psi (3.5-4.5 kg/cm2). Pressure relief valve is located in oil pump
body and is not adjustable.
ENGINE OIL CRANKCASE CAPACITY

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
Microsoft
Sunday, July 05, 2009 1:55:15 PMPage 32 © 2005 Mitchell Repair Information Company, LLC.

OIL PUMP
Removal & Disassembly
1. Disconnect negative battery cable. Remove dipstick, tube and "O" ring. Drain engine oil and coolant.
Remove drive belts, crankshaft and water pump pulleys. Remove generator, A/C compressor and
mounting bracket. Without disconnecting A/C hoses, secure A/C compressor away from engine. Remove
timing belt and related components. See TIMING BELT
under REMOVAL & INSTALLATION.
2. Hold crankshaft sprocket in place and remove crankshaft sprocket bolt. Remove crankshaft sprocket
using steering wheel puller. Leave crankshaft Woodruff key in place.
3. Remove oil pan and oil pump pick-up tube. See OIL PAN
under REMOVAL & INSTALLATION.
Remove oil pump housing assembly. Using a screwdriver protected with a rag, drive oil seal out from
inside of oil pump housing assembly.
4. Remove pump cover screws (use a manual impact screwdriver, if necessary). See Fig. 22
. Remove pump
cover. Note location of alignment marks on inner and outer rotors. Remove inner and outer rotors. To
remove pressure relief valve, remove spring seat, pressure spring and control plunger.
Inspection
Replace pressure relief valve spring if length is not as specified. See OIL PUMP SPECIFICATIONS. Ensure
plunger slides freely in bore. Replace oil pump housing assembly if clearances are not as specified. See OIL
PUMP SPECIFICATIONS .
Reassembly & Installation
1. Apply oil to friction surfaces. Install inner and outer rotors with marks aligned. See Fig. 23 . Install
pressure relief valve components. Apply oil to lip of NEW oil seal. Press oil seal into bore until even with
face of oil pump housing assembly.
2. Install pump cover. Tighten screws to 53-78 INCH lbs. (6-9 N.m). To complete installation, reverse
removal procedure. Tighten bolts to specification. See TORQUE SPECIFICATIONS
.
OIL PUMP SPECIFICATIONS
ApplicationW/O Filter Qts. (L)W/Filter Qts. (L)
Miata & Protege3.8 (3.6)4.0 (3.8)
ApplicationMaximum Clearance In. (mm)
Maximum Rotor Tip Clearance (1) .0079 (.20)
Maximum Rotor-To-Pump Body Clearance (2) .0079 (.20)
Maximum Rotor Side Clearance (3) .0055 (.14)
Pressure Relief Spring Free Length1.809 (45.94)
(1)See Fig. 23 .
(2)Insert feeler gauge between outer rotor and pump body.
Place straightedge across pump body and check clearance between straightedge and both rotors.

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
Microsoft
Sunday, July 05, 2009 1:55:15 PMPage 33 © 2005 Mitchell Repair Information Company, LLC.

Fig. 22: Exploded View Of Oil Pump
Courtesy of MAZDA MOTORS CORP.
(3)

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
Microsoft
Sunday, July 05, 2009 1:55:15 PMPage 34 © 2005 Mitchell Repair Information Company, LLC.

ENGINE SPECIFICATIONS
GENERAL SPECIFICATIONS
Manifold Nut23-34 (31-46)
Exhaust Manifold Nut(1) 28-34 (38-46)
Flywheel Bolt71-76 (96-103)
Fuel Rail Bolt14-19 (19-26)
Generator Top Bolt27-38 (37-51)
Intake Manifold Bolt/Nut(1) 14-19 (19-26)
Intake Manifold Support Bracket14-18 (19-25)
Main Bearing Cap Bolt
Step 1(1) 22-27 (30-37)
Step 2 (Final)(1) 40-43 (54-58)
Oil Pan-To-Transaxle Bolt (Protege)28-38 (38-51)
Oil Pan-To-Transmission Bolt (Miata)48-65 (64-88)
Oil Pump-To-Block Bolt14-19 (19-26)
Power Steering Pump-To-Bracket Bolt28-38 (38-51)
PPF/Differential Spacer Mounting Bolt (2) 27-38 (37-51)
PPF-To-Differential Long Mounting Bolt (2) 77-91 (104-123)
PPF-To-Transmission Side Mounting Bolt (2) 77-91 (104-123)
PPF/Transmission Rear Bracket Mounting Bolt27-40 (37-54)
Spark Plug11-16 (15-22)
Timing Belt Tensioner Bolt27-38 (37-51)
Water Pump Bolt14-19 (19-26)
INCH Lbs. (N.m)
Camshaft Bearing Cap Bolt(3) 100-125 (11.3-14.1)
Cylinder Head Cover Bolt43-78 (5-9)
Oil Jet104-156 (12-18)
Oil Pan-To-Engine Block Bolt
(Miata & Protege)70-95 (8-11)
Oil Pump Cover Screws53-78 (6-9)
Oil Strainer Bolt70-95 (8-11)
Rear Cover Bolt70-95 (8-11)
Water Pump Pulley Bolt70-95 (8-11)
(1)Tighten evenly to specification in alternating sequence.
(2)Tighten in sequence. See Fig. 7 .
(3)Tighten in sequence. See Fig. 10 or Fig. 11 .

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
Microsoft
Sunday, July 05, 2009 1:55:15 PMPage 36 © 2005 Mitchell Repair Information Company, LLC.

CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS
CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS
CONNECTING RODS
ApplicationSpecification
Displacement112.2 Cu. In. (1.8L)
Bore3.27" (83.0 mm)
Stroke3.35" (85.0 mm)
Compression Ratio
Miata9.0:1
Protege8.9:1
Fuel SystemPFI
Horsepower @ RPM
Miata128 @ 6500
Protege103 @ 5500
Torque Ft. Lbs. @ RPM
Miata110 @ 5000
Protege111 @ 4000
ApplicationIn. (mm)
Crankshaft
End Play
Standard.0032-.0111 (.080-.282)
Maximum.0118 (.30)
Maximum Runout.0016 (.04)
Main Bearings
Journal Diameter
Standard Bearings1.9661-1.9667 (49.938-49.956)
Journal Out-Of-Round.002 (.05)
Oil Clearance
Standard.0008-.0014 (.020-.036)
Maximum.004 (.10)
Connecting Rod Bearings
Journal Diameter
Standard Bearings1.7693-1.7699 (44.940-44.956)
Journal Out-Of-Round.002 (.05)
Oil Clearance
Standard.0008-.0027 (.020-.068)
Maximum.0039 (.100)

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
Microsoft
Sunday, July 05, 2009 1:55:15 PMPage 37 © 2005 Mitchell Repair Information Company, LLC.