Editing Z31/Nuts and Bolts (section)

== Engine ==

=== VG30E/ET block, head and manifolds ===

{| class="wikitable"
|-
! Location !! Thread (size × pitch, length) !! Years !! Torque (N·m) !! Torque (ft-lb) !! Source / notes
|-
| Main bearing cap bolts || — || 1986–87 || 90–100 || 67–74 || FSM EM-45 (1986 & 1987) [3][14], EM-31. Tighten in order, in two or three stages.
|-
| Connecting rod cap nuts || — || 1986–87 || 44–54 || 33–40 || FSM EM-45 (1986 & 1987) [3][14], EM-32. FSM: oil the threads and nut seating surfaces.
|-
| Cylinder head bolts || — || 1987 || see notes || see notes || FSM EM-23 [3]. Procedure: (1) all to 29 N·m (22 ft-lb); (2) all to 59 N·m (43 ft-lb); (3) loosen all completely; (4) all to 29 N·m (22 ft-lb); (5) all to 54–64 N·m (40–47 ft-lb), or turn 60–65° with an angle wrench. Bolt lengths: 127 mm and 106 mm (positions in FSM figure).
|-
| Camshaft sprocket bolts || M10 × 1.25, measured at 28 mm (30 mm also works) || All || 78–88 || 58–65 || Size: rev 7952 contribution (Z31-R chat) [13]. Torque: FSM EM-23, EM-45 [3]; 1986 EM-45 "Camshaft pulley" same [14]; same values as the lemon-manuals.la reference cited in that edit [13].
|-
| Rocker cover bolts || — || 1986–87 || 1–3 || 0.7–2.2 || FSM EM-45 (1986 & 1987) [3][14]
|-
| Rocker shaft bolts || — || 1986–87 || 18–22 || 13–16 || FSM EM-45 (1986 & 1987) [3][14]. Tighten in two or three stages (EM-24).
|-
| Oil pan bolts || M6 × 1.0, 14 mm, bolt + split washer || All || 5–7 || 3.6–5.1 || Size [1]; torque FSM EM-45 [3]; same in 1986 EM-45 [14]
|-
| Oil pan drain plug || — || 1986–87 || 29–39 || 22–29 || FSM EM-45 (1986 & 1987) [14], MA-42 [3][12]
|-
| Spark plugs || — || 1986–87 || 20–29 || 14–22 || FSM EM-45 (1986 & 1987) [14], MA-18, MA-42 [3][12]
|-
| Harmonic balancer (crank pulley) to crank || M10 × 1.0, 120 mm, bolt + flat washer || 84–87 || rowspan="3" | 123–132 || rowspan="3" | 90–98 || Size [1]. Torque: FSM EM-45, MA-22 [3][12]; same in 1986 EM-45 [14].
|-
| Harmonic balancer (crank pulley) to crank || M12 × 1.25, bolt + flat washer || 88–89 || Size [1] (length not recorded).
|-
| Crank pulley bolt (G-E's sample) || M12 × 1.25 × 80 mm, washer 35 mm OD × 8 mm thick || not stated || Forum, G-E 2014-08-12 [2]. G-E asked for someone to check this against other cars.
|-
| Pulleys to harmonic balancer || M6 × 1.0, 15 mm, bolt + split washer || All || — || — || Size [1]
|-
| Flywheel to crank (manual) || M10 × 1.0, 24 mm long (3 mm shoulder), JIS flange head || not stated || 98–108 || 72–80 || Size: forum, G-E 2014-12-28 [2] (his earlier post guessed ~30 mm). Torque: FSM EM-45 (1986 & 1987) [3][14].
|-
| Pressure plate to flywheel || M8 × 1.25, 17 mm long (4 mm shoulder), JIS flange head || not stated || — || — || Forum, G-E 2014-12-28 [2]
|-
| Drive plate to crankshaft (automatic) || — || 1987 || 137–157 || 101–116 || FSM AT-92 [6]
|-
| Timing belt tensioner nut || M10 × 1.25, nut + flat washer || All || 43–58 || 32–43 || Size [1]; torque FSM EM-45, MA-20 [3][12]; same in 1986 EM-45 [14]
|-
| Thermostat housing || M8 × 1.25, 72 mm, bolt + split + flat washer || All || rowspan="2" | 16–21 || rowspan="2" | 12–15 || Size [1]; torque FSM LC-16 "Thermostat housing securing bolt" [4]
|-
| Thermostat housing cover || M8 × 1.25, 34 mm, bolt + split + flat washer || All || Size [1]
|-
| Intake manifold nuts || — || 1987 || 1st: 3–5; 2nd: 24–27 || 1st: 2.2–3.6; 2nd: 17–20 || FSM EM-24 [3]. Tighten in two or three stages.
|-
| Intake manifold bolts || — || 1987 || 1st: 3–5; 2nd: 16–20 || 1st: 2.2–3.6; 2nd: 12–14 || FSM EM-24 [3]
|-
| Exhaust manifold || M8 × 1.25 studs || 84–87 || rowspan="2" | 18–22 || rowspan="2" | 13–16 || Size [1]. Torque: FSM EM-45, 1987 [3] and 1986 [14] (not yet checked for 88–89).
|-
| Exhaust manifold || M10 × 1.25, 30 mm bolts || 88–89 || Size [1]
|-
| Turbocharger unit (ET) || — || 1986–87 || 44–54 || 33–40 || FSM EM-45 (1986 & 1987) [14] "Turbocharger unit" [3]
|-
| Turbine to downpipe (ET) || M10 × 1.5 studs || All || — || — || Size [1]
|-
| Turbo oil feed tube (ET), at cylinder block || — || 1986–87 || 15–20 || 11–14 || FSM EM-45 (1986 & 1987) [14] "Oil feed tube"; LC-15 "Oil inlet tube to cylinder block" [3][4]
|-
| Turbo oil inlet tube (ET), at turbocharger || — || 1987 || 8–11 || 5.8–8.0 || FSM LC-15 [4]
|}

=== Lubrication ===

{| class="wikitable sortable"
|-
! Location !! Thread (size × pitch, length) !! Years !! Torque (N·m) !! Torque (ft-lb) !! Source / notes
|-
| Oil pump bolts || M6 × 1.0, 20 mm and 30 mm, bolt + split washer || All || 6–7 || 4.3–5.1 || Size [1]; torque FSM LC-15 (M6 securing bolt), EM-45 [4][3]
|-
| Oil pressure switch (sender) port || 1/8" BSPT || All || 13–17 || 9–12 || Size [1]; torque FSM LC-3, LC-15 "Oil pressure switch" [4]
|-
| Oil temperature sensor bung (turbo) || M16 × 1.5 || All (turbo) || — || — || Size [1]. Note: M16 × 1.5 is the oil ''temperature'' bung, not the pressure sender.
|-
| Oil filter bracket to cylinder block || — || 1987 || 14–18 || 10–13 || FSM LC-15 [4]
|-
| Oil filter stud || — || 1987 || 59–74 || 43–54 || FSM LC-15 [4]
|}