Removal
- Disconnect negative battery cable. Remove air cleaner and intake air duct. Release fuel pressure. See «FUEL PRESSURE RELEASE & PRIMING»(ref-8459-S38751688962000083000000). Drain coolant. Note locations and disconnect all necessary electrical connectors, ground wires, vacuum hoses, fuel lines, coolant hoses and control cables. Plug all fuel lines to avoid leakage.
- Remove timing belt. See «TIMING BELT»(ref-8459-S21131665092000083000000). On Protege models, remove power steering pump and bracket with hoses attached, and suspend aside. On all models, disconnect exhaust pipe flange from WU/TWC. Remove exhaust manifold heat shield.
- Disconnect throttle cable, and remove bracket. Remove ignition coil. Remove intake and exhaust manifold support brackets. Remove camshaft sprockets. Mark camshaft bearing caps for installation reference. Loosen bearing cap bolts, a few turns at a time, in the sequence shown. (Scheme 16)or (Scheme 17). Remove camshafts. Loosen cylinder head bolts, in 3 steps, and in sequence. (Scheme 18) Remove cylinder head assembly.
Scheme 16
Scheme 17
Scheme 18
- Install NEW cylinder head gasket. Install cylinder head. Tighten bolts to specification, in 2-3 steps, and in sequence. (Scheme 19) See «TORQUE SPECIFICATIONS»(ref-8459-S35201973112000083000000).
- Apply oil to camshaft journals, and install camshafts so that lobes are pointing up on No. 1 and No. 3 cylinders, as shown. (Scheme 20) Apply silicone sealant to cylinder head mating surfaces of camshaft caps No. 1 and No. 6. Install camshaft caps in original locations. On Protege, hand tighten bolts No. 2, 4, 5, and 7. (Scheme 21) On all models, tighten camshaft cap bolts to specification, in 2-3 steps, and in sequence. (Scheme 21)or (Scheme 22). See «TORQUE SPECIFICATIONS»(ref-8459-S35201973112000083000000).
- Apply oil to camshaft oil seal. Using Seal Driver (49-T028-302 for Miata, or 49-B014-001 for Protege), install camshaft oil seal. Rotate camshafts until camshaft dowel pins face straight up. On Miata, install camshaft sprockets with the "I" mark (intake side), or "E" mark (exhaust side) facing straight up. (Scheme 23) On Protege, install camshaft sprockets with the dowel pins straight up and the "I" and "E" facing each other. (Scheme 24) Hold camshafts by using a wrench on the cast hexagon on camshafts, and tighten sprocket lock bolts to specification. See «TORQUE SPECIFICATIONS»(ref-8459-S35201973112000083000000). To complete installation, reverse removal procedure. Fill cooling system with coolant and bleed system. See «COOLING SYSTEM BLEEDING»(ref-8459-S42368429102000083000000).
Scheme 19
Scheme 20
Scheme 21
Scheme 22
Scheme 23
Scheme 24
Disconnect negative battery cable. Remove drive belts and water pump pulley. Remove crankshaft pulley, timing belt covers and timing belt. See TIMING BELT . Remove crankshaft sprocket and Woodruff key. Remove crankshaft seal.
- Apply oil to seal lip. Using a hammer and Seal Driver (49-B014-001) for Miata, or (49-H010-401) for Protege, tap seal into oil pump body until flush with edge of pump body. DO NOT bottom seal in pump body. Install crankshaft sprocket and Woodruff key with tapered side of key facing toward oil pump body.
- Install timing belt. See «TIMING BELT»(ref-8459-S21131665092000083000000) . Install timing belt covers, pulleys and drive belts. To complete installation, reverse removal procedure.