Engine Disassembly and Assembly
Camshaft timing chains
Camshaft cases and cylinder heads, removing..............102-12
Camshaft cases, camshafts and camshaft timing chains, installing ... .102-28
TABLE
a. Crankshaft Gear Circlip Thickness............102-18
Special tool
A P 238 a...........................Flywheel locking tool
(Porsche ordering #000 721 238 10)
B P 201/201 b..........Four-arm engine mount and adapters
(Porsche ordering #000 721 201 00/20)
C 9191............Camshaft sprocket counterholding wrench
(Porsche ordering #000 721 919 10)
D P 212....................Camshaft sprocket lockpin tool
(Porsche ordering #000 721 212 00)
GENERAL
This repair group covers engine disassembly and reassembly. Engine removal procedures, including separating the transmission from the engine, are covered in 101 Engine Removal and Installation.
The repair information given here requires that the engine be removed from the car. The disassembly procedure should be carried out on an appropriate engine stand in a clean environment.
^ Some of the procedures require special tools.
Reconditioning procedures and specifications are not covered here. Once the engine is disassembled to the component level, refer to the appropriate repair group for applicable reconditioning information.
• 130 Crankcase and Crankshaft
• 131 Pistons and Cylinders
• 150 Cylinder Heads
• 151 Camshafts and Camshaft cases
• 152 Camshaft Timing Chains
Special Tools
Special tool
E P 204.....................Timing chain idler pulley brace
F 9236............................Pulley spanner wrench
(Porsche ordering #000 721 923 60)
G P 209 ......................Crankshaft mounting bracket
H P 221 .. Left connecting rods support during engine assembly (Porsche ordering #000 721 221 00)
I P 222 .....Left timing chain support during engine assembly
(Porsche ordering #000 721 222 00)
J US 1008a.......................Piston ring compressor
K P 140 .... Nuts for securing cylinders during engine assembly (Porsche ordering #000 721 140 00)
L P 207 ......................Dial gauge mounting bracket
(Porsche ordering #000 721 207 00)
• The pulley end of the engine is referred to as the front. The flywheel end of the engine is referred to as the rear.
• If the engine is disassembled because of bearing failure, a thorough flushing of the lubrication system must be carried out prior to reassembly. Refer to 130 Crankcase and Crankshaft and 170 Engine Lubrication.
Some repair operations do not require engine removal and disassembly. Some of the more common engine-installed operations are as follows:
' Camshaft timing adjustment and timing chain and tension-er replacement. See 152 Camshaft Timing Chains.
• Camshafts and rocker arm replacement. See 151 Camshafts and Camshaft Cases.
• Leaky engine oil return tube replacement. See 170 Engine Lubrication.
ENGINE, DISASSEMBLY
The disassembly procedure is divided into subsections as follows:
♦ Engine peripherals, removing
♦ Camshaft timing chains and camshafts, removing
► Camshaft cases and cylinder heads, removing
♦ Pistons and cylinders, removing
♦ Crankcase, disassembling
♦ Crankshaft, disassembling
Crankcase assembly
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1. Oil pressure switch -torque to 20 Nm (15 ft-lb)
2. Switch adapter -torque to 35 Nm (26 ft-lb)
3. Sealing ring (18 x 24mm)
4. Oil thermostat
5. Thermostat sealing O-ring (39.2 x 3 mm)
6. Case bolt sealing ring
7. Case bolt beveled washer
9. Crankcase
10. Case bolt
11. Oil pressure sensor -torque to 35 Nm (26 ft-lb)
12. Oil pressure sensor sealing ring (18x24 mm)
13. Oil pressure sensor adapter bolt, -torque to 35 Nm (26 ft-lb)
14. Adapter bolt sealing ring (12x16 mm)
15. Transmitter adapter housing
16. Oil temperature sensor -torque to 25 Nm (18 ft-lb)
17. Temperature sensor sealing ring
18. Front pulley bolt -torque to 80 Nm (59 ft-lb)
19. Front pulley
20. Intermediate shaft cover bolt
21. Intermediate shaft cover bolt washer
22. Intermediate shaft cover
23. Crankshaft oil seal, front
24. Chain guide rail bolt
25. Guide rail bolt sealing ring (10x16 mm)
26. Chain guide rail
27. Oil drain plug
28. Drain plug sealing ring (22 x 27 mm)
29. Oil pressure relief valve piston
30. Oil pressure relief valve spring
31. Oil pressure relief valve sleeve
33. Oil pressure relief valve plug -torque to 60 Nm (44 ft-lb)
34. Line adapter sealing ring, (22 x 27mm)
35. Oil line adapter
36. Oil pressure safety valve spring
37. Cylinder head alien nut
38. Cylinder head washer
39. Cylinder head stud
40. Crankshaft oil seal, rear
41. Flywheel
42. Heater blower after-run temperature switch
43. Temperature switch sealing ring
44. Breather cover
45. Breather cover gasket
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¡^Engine peripherals, removing
Remove clutch bolts (arrows). Remove clutch from flywheel.
Hold flywheel stationary with Porsche special tool P 238 (remove inner pin from tool) or equivalent locking device and loosen flywheel bolts (arrows). Remove flywheel.
— Remove metal shrouding from flywheel end of engine.
Remove TDC sensor bracket bolts from top of engine (arrows). Remove sensor.
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— Mount engine on engine stand.
A 4-arm or 5-arm engine stand adapter (Porsche special tool P 201) should be used to mount the engine. 3-arm and"generic" engine stands are dangerous and may damage the engine block.
— Remove metal shrouding from pulley end of engine.
— Remove engine support crossmember.
— Rotate engine on stand so exhaust system is on top. Lock engine stand in this position.
^ Remove heat exchanger mounting nuts (arrows). Right side shown.
— Remove muffler retaining straps.
— Remove heat exchanger crossover tube.
— Remove exhaust system as a complete unit. See 260 Exhaust System.
— Remove muffler support bracket.
— Rotate engine so that intake side is up. Lock engine stand in this position.
^ Remove A/C compressor mounting bracket and engine support bracket bolts (arrows).
• Remove brackets.
• Note blind mounting nut on reverse side of engine support bracket.
During disassembly, check for oil leakage at upper right mounting stud at rear engine carrier (A). If oil leakage is present, see 130 Crankcase and Crankshaft for specific repair information.
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^ Remove intake runner fasteners from cylinder heads.
^ Disconnect electrical harness connectors on engine:
• Oil pressure warning light switch (B)
• Oil temperature sender (C)
• Heater blower after-run temperature switch (D)
- _A 0018050
— Slide oil cooler off mounting studs.
— Disconnect spark plug connectors. Unclip and remove distributor cap with wires.
— Remove left and right metal shrouding.
^ Pry off throttle linkage from bellcrank (arrow 1).
• Remove bell crank mounting nuts and remove bellcrank with spacer (arrow 2) from top of engine.
— Carefully lift off complete fuel system, intake manifolds and alternator with cooling shroud.
^ Remove oil cooler mounting nuts from top and bottom (arrows) of cooler.
— Slide oil cooler off mounting studs.
^ Remove cooling fan/alternator housing:
• Remove fan/alternator drive belt. See 030 Maintenance.
• Remove alien bolt (A) from fan housing strap.
• Remove bolts (B) from engine cooling shroud.
• Remove spark plug wire supports (C).
• Pull alternator out partially and unbolt alternator ground strap from top of engine crankcase.
Once the drive belt is removed, reinstall alternator belt pulley and shims and tighten nut fingertight.
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^ Check cast oil pipe webbing (arrows) in right crankcase half (lower oil cooler area) for oil leakage due to porous casting material.
— To repair, thoroughly clean crankcase in problem area using alcohol or acetone.
• Fill area with Silastic® 732 RTV sealing compound or equivalent using light uniform pressure until depression is filled.
^ Remove following parts from engine:
• Intermediate shaft end cover (A).
►Camshaft timing chains and camshafts, removing
^ Set crankshaft to Z1 (TDC) cylinder 1 compression stroke (arrow).
— Remove intake and exhaust valve covers on both sides of engine.
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Loosen all valve adjuster lock nuts and fully back off adjusting screws for all valves.
^ Working at cylinder 1, counterhold rocker shaft nut with 8 mm alien wrench, then loosen opposite end with 5 mm alien wrench.
Mark location of each rocker arm. Do not interchange used parts.
^ Gently tap rocker shaft out and remove rocker arm.
— Turn crankshaft 120° in normal direction of rotation. Remove cylinder 6 rocker arms using above procedure.
— Following firing order, turn crankshaft 120° and remove rocker arms for next cylinder. Repeat until all rocker arms are removed.
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^ Remove left camshaft case oil feed line pressure fittings (A).
• Remove left chain tensioner oil feed line pressure fitting (B).
• Remove left chain housing coverfasteners (small arrows), and remove cover.
^ Loosen left camshaft sprocket mounting bolt. NOTE —
Use Porsche special tool 9191 or equivalent to counterhold camshaft sprocket when loosening bolt.
Compress timing chain tensioner using large pliers.
• Lock tensioner down using 3 mm pin through hole in tensioner body (1).
• Special tool P 204 (2) can be used to brace idler sprocket before removing tensioner.
Check timing chain tensioner piston height before compressing. If piston is fully extended, carefully inspect timing chains and sprockets for wear. See 152 Camshaft Timing Chains.
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^ Remove timing chain tensioner (A) and idler sprocket assembly (B) with special brace P 204 if installed.
— Remove camshaft sprocket bolt from left camshaft (C).
Remove camshaft sprocket lockpin using Porsche special tool P 212 or equivalent.
— Remove camshaft sprocket and disengage from timing chain.
— Remove sprocket flange.
Remove left camshaft:
• Remove woodruff key (A) from camshaft.
• Remove camshaft end cover retaining bolts (arrows) and remove camshaft end cover (B), shims and thrust spacer.
• Slide camshaft toward pulley end of engine to remove.
• Wire tie end cover, shims and thrust spacer together and label.
• For identification, the left camshaft is marked "147-10" on the end.
— Remove left timing chain housing.
— Repeat procedures on right side camshaft.
For identification, the right camshaft is marked "148-10" on the end.
^ Remove left side upper and lower timing chain guide rails by removing mounting bolts.
— Repeat procedures for right side chain guide rails. Note lower right guide rail is different from all other chain guide rails.
ICamshaft cases and cylinder heads, removing
Remove 18 nuts (arrows) from left camshaft case.
— Remove camshaft case and mark for left side.
— Rotate engine on stand. Working on left side bottom of crankcase, remove oil pressure line and all brackets holding it to crankcase.
— Remove cylinder head nuts from each cylinder head using long 10 mm alien wrench.
— Remove cylinder heads, marking installed locations.
— Repeat procedures for right side.
• Check for broken cylinder head studs when removing the cylinder heads. If any are found, check area around cylinder head and base of stud for signs of blow-by. If blow-by is present, mark that area on both cylinder and head for further inspection once the parts are thoroughly cleaned.
• Various head studs have been used on the Carrera 911 engines. Always check with an authorized Porsche parts department for the latest in parts information.
^ Disassemble cylinder heads using Porsche special tool
P 200 or equivalent.
• Remove valve keepers, spring retainers, springs, valve stem seals, spacer shims and spring seats.
• Mark location of valves and remove from cylinder head.
- .0018333.
- 0018711
IPistons and cylinders, removing
— Remove cylinder air shroud plates.
— Mark cylinder locations on each cylinder barrel.
IPistons and cylinders, removing
— Remove cylinder air shroud plates.
— Mark cylinder locations on each cylinder barrel.
Label all parts during disassembly. Used parts must be reinstalled in their exact location and position.
^ Remove cylinders. If necessary, use a soft-faced hammer to tap cylinders off studs.
^ Remove wrist pin circlips from piston 1.
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0018345r
^ Using a soft drift, tap wrist pin out of piston 1. • Remove piston, marking its position.
— Rotate crankshaft 240°. Remove piston 2, marking its position.
When rotating crankshaft, manually guide pistons in and out of crankcase bores in order to avoid damaging the piston skirts or rings. Use shop towels around the pistons for protection.
— Rotate crankshaft appropriate amount and remove remaining pistons, marking positions.
- 008029b
ICrankcase, disassembling
^ Remove both oil pressure relief valve assemblies in front bottom of crankcase.
— Remove crankshaft pulley bolt using Porsche special tool 9236 or equivalent to counterhold pulley. Remove pulley.
^ Remove M8 nuts (arrows) joining case halves together.
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^ Remove M10 case nuts (arrows) located in oil cooler housing.
Remove M10 case nut (arrow) from left timing chain housing.
— Remove remaining M10 case nuts (quantity 11) on left side, counterholding case bolt heads on right side of crankcase.
— Carefully separate crankcase halves.
CAUTION—
Do not pry case apart at sealing surfaces. A damaged surface will result in an oil leak.
— Lift left half of crankcase off and set aside.
— Lift crankshaft assembly out of crankcase and set aside.
^ Bend back locking tabs on oil pump mounting nuts (arrows). Remove nuts.
— Remove and disassemble intermediate shaft by removing timing chains, oil pump and oil pump drive shaft.
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♦Crankshaft, disassembling
— Mount crankshaft to Porsche special tool P 209 or equivalent and clamp tool with crankshaft in shop vise.
An adequate substitute for special tool P 209 can be made from an old flywheel.
Mark installed position of connecting rods and remove from crankshaft.
— Slide crankshaft nose bearing off crankshaft.
— Remove circlip holding gear assembly to crankshaft.
Remove gear assembly on front of crankshaft using suitable gear puller.
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