1997 MAZDA MX-5 head gasket

2. Disconnect throttle cable. Remove fuel lines from fuel rail and pressure regulator. Remove throttle body
intake duct housing and throttle body. Remove by-pass air control valve and solenoid valves. Remove
upper intake manifold (if equipped).
3. Remove intake manifold support bracket from underneath manifold. Disconnect injector harness
connectors, and remove injectors/fuel rail assembly. Remove intake manifold and gasket.
Installation
1. Ensure all gasket surfaces are clean and flat. Using NEW gasket, install intake manifold to cylinder head.
Tighten manifold bolts/nuts evenly to specification, starting from center bolt and alternating outward. See
TORQUE SPECIFICATIONS
. Install support bracket underneath intake manifold.
2. Install gasket and upper intake manifold (if equipped). Tighten bolts/nuts evenly to specification,
alternating from top to bottom. See TORQUE SPECIFICATIONS
.
3. To complete installation, reverse removal procedure. Ensure throttle cable has .04-.12" (1-3 mm) free
play. Ensure injectors twist freely and are not cocked in insulator "O" rings. Refill engine with coolant.
EXHAUST MANIFOLD
Removal & Installation
1. Remove air cleaner intake duct from top of radiator/fan assembly (if equipped). Disconnect oxygen
sensor. Remove heat shields. Disconnect down pipe from exhaust manifold. Remove exhaust manifold.
2. To install, reverse removal procedure. Ensure all mating surfaces are clean and flat. Install NEW exhaust
manifold gasket to cylinder head. Tighten manifold bolts evenly to specification, starting from center bolt
and alternating outward. See TORQUE SPECIFICATIONS
.
CYLINDER HEAD
Removal
1. Release residual pressure from fuel system. See FUEL PRESSURE RELEASE & PRIMING . Drain
engine coolant. Note locations and disconnect all necessary electrical connectors, ground wires, vacuum
hoses, fuel hoses, coolant hoses and control cables for cylinder head removal. Plug all fuel hoses to avoid
leakage.
2. Remove spark plug wires from spark plugs. Remove all drive belts. Remove water pump pulley. Remove
timing belt. See TIMING BELT
. Remove camshaft/rocker cover.
3. Remove front exhaust pipe. Remove intake manifold support bracket. Loosen all cylinder head bolts
evenly, in 3 steps, in reverse of tightening sequence. See Fig. 7
. Remove bolts and cylinder head
assembly.
Inspection
Carefully clean carbon and gasket material from all mating surfaces. Clean threads of cylinder head bolts. Use a
tap to clean threads in engine block. Check cylinder head for warpage. Resurface or replace head if it is not
within specification. Check valve train components. Replace or resurface components if they are not within

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
Microsoft
Sunday, July 05, 2009 1:55:15 PMPage 10 © 2005 Mitchell Repair Information Company, LLC.

specification. See CYLINDER HEAD and VALVES & VALVE SPRINGS tables under ENGINE
SPECIFICATIONS .
Installation
Install cylinder head gasket, cylinder head assembly and bolts. Tighten cylinder head bolts in 2 steps, and in
sequence, to specification. See Fig. 7
. See TORQUE SPECIFICATIONS . To complete installation, reverse
removal procedure.
Fig. 7: Cylinder Head Bolt Tightening Sequence

Courtesy of MAZDA MOTORS CORP.
CRANKSHAFT FRONT SEAL
Removal
Disconnect negative battery cable. Remove drive belts and crankshaft pulley. Remove water pump pulley,
timing belt covers and timing belt. See TIMING BELT
. Use Crankshaft Lock Tool (49-D011-102) to lock
crankshaft sprocket into position. Remove crankshaft sprocket bolt. Remove crankshaft sprocket usin
g steering

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
Microsoft
Sunday, July 05, 2009 1:55:15 PMPage 11 © 2005 Mitchell Repair Information Company, LLC.

Courtesy of MAZDA MOTORS CORP.
Removal & Installation (Protege)
1. Disconnect negative battery cable. Remove engine undercovers. Drain engine oil. Remove exhaust header
downpipe and brackets from front exhaust system. Remove oil pan retaining bolts.
2. DO NOT damage sealant contact surfaces. Remove oil pan by prying between oil pan and mounting
surface. On Protege, remove stiffener by prying between stiffener and cylinder block. On all models,
clean all sealant from oil pan, bolts, engine block and both sides of stiffener (Protege).
3. On Protege, apply oil resistant sealant to engine block and stiffener. Install stiffener. On all models, apply
sealant and install oil pan within 5 minutes of applying sealant. To complete installation, reverse removal
procedure. Tighten all bolts to specification. See TORQUE SPECIFICATIONS
. Fill engine with oil to
specification. See ENGINE LUBRICATION SYSTEM
under ENGINE OILING.
OVERHAUL
CYLINDER HEAD
Cylinder Head
Clean carbon and gasket material from all mating surfaces. Using a tap, clean cylinder head threads. Check
cylinder head warpage. If warpage exceeds specification, resurface head, but DO NOT exceed grinding limit.
See CYLINDER HEAD
under ENGINE SPECIFICATIONS. After resurfacing cylinder head, check cylinder
head height. Replace cylinder head if height is less than minimum specification.
Valve Springs
Ensure valve spring free length, out-of-square and compressed length are within specification. See VALVES &
VALVE SPRINGS under ENGINE SPECIFICATIONS. Replace valve spring if necessary.
Valve Stem Oil Seals
1. On Miata, use Installer Set (49-L012-0A0) to install valve seals. See Fig. 15 . Adjust installer dimension
"L" to seal depth of .720-.744" (18.3-18.9 mm). Using hand pressure ONLY, install seal until it contacts
cylinder head. Lightly oil valve seal lip.
2. On Protege, use Installer Set (49-L012-0A0) to install valve seals. See Fig. 15
. Adjust installer
dimension "L" to seal depth of .783" (19.9 mm). Using hand pressure, install seal until it contacts cylinder CAUTION: If reusing old oil pan bolts, remove old sealant from bolt threads.
Failure to remove old sealant may result in cracked block at bolt
holes.
NOTE: Intake and exhaust valve stem seals are different. Exhaust seals can be
identified by ridges molded into top of seal. Intake seals do not have identifying
ridges. Incorrect installation of valve stem seals will cause premature failure.

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
Microsoft
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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.