1997 MAZDA MX-5 check engine

1997-98 ENGINES
1.8L 4-Cylinder
ENGINE IDENTIFICATION
Engines can be identified by engine model and number. See ENGINE IDENTIFICATION CODE. On Miata,
engine model and number are stamped on flange at upper right rear of cylinder block deck, as viewed from
flywheel. On Protege, engine model and number are stamped on flange at upper left rear of cylinder block deck,
as viewed from flywheel.
ENGINE IDENTIFICATION CODE
ADJUSTMENTS
VALVE CLEARANCE ADJUSTMENT
REMOVAL & INSTALLATION
FUEL PRESSURE RELEASE & PRIMING
Releasing Pressure (Miata)
Locate and remove fuel pump relay from under left side of dash, near steering column. Start engine and allow to
stall. After engine stalls, attempt to restart engine to ensure no residual pressure exists. Turn ignition off and
reinstall fuel pump relay. When disconnecting fuel hoses, cover connection with shop rag to catch fuel leakage.
To avoid excessive cranking after servicing, prime fuel system before starting engine.
Releasing Pressure (Protege)
NOTE: For repair procedures not covered in this article, see ENGINE OVERHAUL
PROCEDURES article in GENERAL INFORMATION.
ApplicationCode
Miata & Protege (1.8L DOHC)BP
NOTE: Valve clearance is not adjustable. Some Hydraulic Lash Adjuster (HLA) noise
may occur during engine start-up. Noise should disappear after engine reaches
normal operating temperature. If noise persists and oil level is okay, change
engine oil. If oil change does not reduce noise, check with manufacturer for
modified HLA.
NOTE: For reassembly reference, label all electrical connectors, vacuum hoses and
fuel lines before removal. Also place mating marks on engine hood and other
major assemblies before removal.

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

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
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Remove rear seat cushions. Disconnect fuel pump connector. Start engine and allow to stall. After engine stalls,
attempt to restart engine to ensure no residual pressure exists. Turn ignition off and reconnect fuel pump
connector. When disconnecting fuel hoses, cover connection with shop rag to catch fuel leakage. To avoid
excessive cranking after servicing, prime fuel system before starting engine.
Priming System
Ensure fuel system is closed. Connect jumper wire between F/P and GND terminals of data link connector. See
Fig. 1
. Turn ignition on for about 10 seconds and check for fuel leaks. Turn ignition off and disconnect jumper
wire.
Fig. 1: Identifying Data Link Connector Terminals (Typical)

Courtesy of MAZDA MOTORS CORP.
COOLING SYSTEM BLEEDING
1. Slowly pour coolant into radiator at a rate of 1.1 qt. (1.0L) per minute maximum until coolant is level
with filler port. Fill coolant reservoir to "F" mark. Securely install radiator cap. Start engine.
2. Operate engine at idle until normal operating temperature is reached. If coolant level warning light
illuminates during warm-up, turn engine off and check drain plug and coolant hoses for leaks. Operate
engine at 2200-2800 RPM for 5 minutes. Stop engine and allow to cool.
3. Repeat steps 1) and 2). Check coolant level. If engine coolant is not level with filler neck, repeat entire
procedure. If engine coolant is level with filler neck, fill reservoir to "F" mark.
CAUTION: If engine overheats during procedure, system contains excessive air. Stop
engine and allow it to cool, then repeat step 1).

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
Microsoft
Sunday, July 05, 2009 1:55:15 PMPage 2 © 2005 Mitchell Repair Information Company, LLC.

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.

Inspection (All Models)
Check timing belt for cracks, peeling, abrasion or other damage. Check tensioner bearing for looseness or
roughness of rotation. Inspect tensioner spring for stretching. Replace parts as necessary.
Installation (All Models)
1. Position notch on crankshaft sprocket to 12 o'clock position (aligned with mark on oil pump). Align
timing marks on camshaft sprockets. See Fig. 8
. Ensure crankshaft timing mark is at TDC. Install belt
around crankshaft sprocket, then working in a counterclockwise direction, route belt around camshaft
sprockets.
2. Loosen timing belt tensioner lock bolt and allow spring to apply tension on belt. Snug tensioner lock bolt.
Rotate crankshaft 2 complete turns in direction of normal engine rotation. Ensure timing marks align. If
timing marks are not aligned, remove belt, realign all timing marks, and repeat installation procedure.
3. Check timing belt deflection with 22 lbs. (10 kg) of pressure applied to belt. See Fig. 9
. Ensure timing
belt deflection is within specification. See TIMING BELT DEFLECTION
.
TIMING BELT DEFLECTION
Application(1) Deflection In. (mm)
Miata & Protege.35-.45 (9.0-11.5)
(1)Deflection measurement is with 22 lbs. (10 kg) of pressure applied to timing belt. See Fig. 9 .

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
Microsoft
Sunday, July 05, 2009 1:55:15 PMPage 13 © 2005 Mitchell Repair Information Company, LLC.

Fig. 9: Measuring Timing Belt Deflection
Courtesy of MAZDA MOTORS CORP.
HYDRAULIC LASH ADJUSTER (HLA)
Removal
Disconnect negative battery cable. Remove camshaft. See CAMSHAFT . Mark location of each HLA for
reassembly reference. Remove HLA from cylinder head.
Inspection
Place HLA in palm of hand. Attempt to compress HLA plunger with thumb. If plunger compresses, replace
HLA.
NOTE: If hydraulic lash adjusters are persistently noisy, check with manufacturer for
availability of modified adjusters.

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

Installation
Insert HLA in original location. To complete installation, reverse removal procedure. Tighten camshaft bearing
caps evenly in sequence to specification. See Fig. 10
or Fig. 11 . See TORQUE SPECIFICATIONS .
CAMSHAFT
Removal
Remove cylinder head cover. Remove timing belt. See TIMING BELT. Remove distributor/camshaft position
sensor. Reference mark camshafts, caps and sprockets, and remove sprockets. Loosen camshaft bearing cap
bolts evenly in 5-6 steps, in sequence. See Fig. 10
or Fig. 11 . Remove camshafts.
Inspection
Check camshaft end play. Check camshaft journal diameters and bearing clearances. Check camshaft lobes for
wear. See CAMSHAFT
under ENGINE SPECIFICATIONS. If any measurement is not within specification,
replace camshaft and/or cylinder head.
Installation
To install, reverse removal procedure. On both camshafts, apply small amount of silicone sealant to contact area
of cylinder head/camshaft seal cover cap. Tighten camshaft bearing cap bolts evenly in sequence to
specification. See Fig. 10
or Fig. 11 . See TORQUE SPECIFICATIONS. NOTE: On Miata, exhaust camshaft has a slot for camshaft position sensor drive. On
Protege, exhaust camshaft has a slot for distributor drive. On all models, match
mark camshafts and sprockets for installation reference.

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
Microsoft
Sunday, July 05, 2009 1:55:15 PMPage 16 © 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
Sunday, July 05, 2009 1:55:15 PMPage 23 © 2005 Mitchell Repair Information Company, LLC.

head. Lightly oil valve seal lip.
Fig. 15: Installing Valve Guide Seals

Courtesy of MAZDA MOTORS CORP.
Valve Guides
1. Check valve stem-to-valve guide oil clearance. Ensure valve guide inside diameter is within specification.
See CYLINDER HEAD
under ENGINE SPECIFICATIONS.
2. Completely disassemble cylinder head. Gradually heat cylinder head in water to 194°F (94°C). Using
Valve Guide Remover (49-B012-005), drive valve guide out, working from combustion chamber side of
cylinder head. Repeat procedure if required, keeping cylinder head hot so aluminum head will not warp.
3. If required, install new circlip on guide. Using proper components of Valve Guide Installer (49-L012-
0A0), adjust installer guide depth (dimension "L") to specification using depth micrometer or caliper. See
VALVE GUIDE INSTALLED HEIGHT
. See Fig. 16 .
4. Insert guide into pre-adjusted installer and drive guide into cylinder head from camshaft side until guide
circlip, and/or installer contact cylinder head. Measure dimension "L" (guide installed height). See Fig.
16 or Fig. 15 . If installed height is not within specification, adjust or replace valve guide or cylinder head
as necessary. See VALVE GUIDE INSTALLED HEIGHT
.
NOTE: On Miata, use only NEW exhaust valve guides to replace intake or exhaust valve
guides.

1997 Mazda MX-5 Miata
1997-98 ENGINES 1.8L 4-Cylinder
Microsoft
Sunday, July 05, 2009 1:55:15 PMPage 24 © 2005 Mitchell Repair Information Company, LLC.