Honda Civic/CRX/del Sol 1984-1995 Repair Guide

Cylinder Head

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PRECAUTIONS



Be sure to inspect the timing belt before removing the cylinder head. Turn the crankshaft pulley so that the number one cylinder is at top dead center. Carefully mark all emission hoses before disconnecting them. This procedure should make it possible to remove the cylinder head without removing the engine from the vehicle.



To prevent warping, the cylinder head should be removed when the engine is cold (below 100°F (38°C).
 
Remove oil, scale or carbon deposits accumulated from each part. When de-carbonizing take care not to score or scratch the mating surfaces.
 
After washing the oil holes or orifices in each part, make sure they are not restricted by blowing out with compressed air.
 
If the parts will not be reinstalled immediately after washing, spray the parts with a rust preventive to protect from corrosion.
 

Taking a few pictures with an instant camera before disassembly could prove to be extremely helpful during assembly.

REMOVAL & INSTALLATION




CAUTION
When draining coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant may be reused unless it is contaminated or several years old.

1984-87 Engines

See Figures 1 through 15

  1. Disconnect the negative battery terminal.
  2.  
  3. Place a clean drain pan under the radiator, remove the radiator cap, the drain plug (from the front side of the engine block, if equipped) and drain the cooling system.
  4.  
  5. To remove the air cleaner, perform the following procedures:
    1. Remove the air cleaner cover and filter.
    2.  
    3. Disconnect the hot and cold air intake ducts, then, remove the air chamber hose.
    4.  
    5. Remove the three bolts holding the air cleaner.
    6.  
    7. Lift the air cleaner housing, then, remove the remaining hoses and the air temperature sensor wire.
    8.  
    9. Remove the air cleaner.
    10.  

  6.  
  7. On fuel injected models, relieve the fuel pressure using the following procedures:
    1. Slowly loosening the service bolt on top of the fuel filter about one turn.
    2.  

  8.  

Place a rag under the filter during this procedure to prevent fuel from spilling onto the engine.

    1. Disconnect the fuel return hose from the pressure regulator. Remove the special nut and then, remove the fuel hose.
    2.  




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Fig. Fig. 1: Cylinder head and components-1984-87 engines

  1. Remove the brake booster vacuum tube from the intake manifold.
  2.  
  3. Remove the engine ground wire from the valve cover and disconnect the wires from the fuel cut-off solenoid valve, the automatic choke and the thermosensor.
  4.  
  5. Disconnect the fuel lines.
  6.  
  7. Label and disconnect the spark plug wires from the spark plugs, then, remove the distributor assembly.
  8.  
  9. Disconnect the throttle cable from the carburetor or throttle body.
  10.  
  11. Disconnect the hoses from the charcoal canister and from the No. 1 control box at the tubing manifold.
  12.  
  13. For California or high altitude models, disconnect the air jet controller.
  14.  
  15. If equipped with air conditioning, disconnect the idle control solenoid hoses.
  16.  
  17. Disconnect the upper radiator heater and bypass hoses.
  18.  
  19. On fuel injected models, disconnect the engine sub harness connectors and the following couplers from the head and the intake manifold.

    The four injector couplers
     
    The TA sensor connector
     
    The ground connector
     
    The TW sensor connector
     
    The throttle sensor connector
     
    The crankshaft angle sensor coupler
     

  20.  

  1. Remove the thermostat housing-to-intake manifold hose.
  2.  



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Fig. Fig. 2: Cylinder head and components-1985-87 fuel injected models

  1. Disconnect the oxygen sensor coupler.
  2.  
  3. Remove the exhaust manifold bracket and manifold bolts, then, remove the manifold.
  4.  
  5. Remove the bolts from the intake manifold and bracket.
  6.  
  7. Disconnect the breather chamber-to-intake manifold hose.
  8.  
  9. Remove the valve and timing belt covers.
  10.  
  11. Loosen the timing belt tensioner adjustment bolt, then, remove the belt.
  12.  
  13. Remove the cylinder head bolts in the reverse order given in the head bolt torque sequence.
  14.  



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Fig. Fig. 3: Loosening the cylinder head bolts using a breaker bar-once they are cracked loose, a ratchet will work best

Loosen the bolts1/3of a turn each time and repeat the sequence to prevent cylinder head warpage.

  1. Carefully remove the cylinder head from the engine.
  2.  
  3. Using a putty knife, clean the gasket mounting surfaces.
  4.  



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Fig. Fig. 4: Use a gasket scraper to thouroughly clean the remaining gasket material from the mating surfaces. Take care that teh blade is clean and sharp so as to not score the surfaces as you clean



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Fig. Fig. 5: Using a breaker bar to loosen the head bolts-1985-87 fuel injected engine shown



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Fig. Fig. 6: Removing one of the special cylinder head bolts rom the Civic cylinder head. Notice special oil flow grooves spiraling down the shaft



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Fig. Fig. 7: The cylinder head is here lifted from the engine with its two-piece intake manifold and throttle body still attached. These will be much easier to remove (if necessary) in the open space of a work bench



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Fig. Fig. 8: Top-side view of the entire cylinder head assembly with attached distributor (complete with spark plug wires), intake manifold and throttle body as it is lifted from the engine

To install:
  1. Scrape any remaining gasket material from the mating surfaces and install a new head gasket. Be sure to pay attention to the following points:
    1. The No. 1 cylinder must be at top dead center with the camshaft pulley UP mark (if applicable, see also Routine Maintenance for timing belt replacement) on top before positioning the head in place.
    2.  
    3. The cylinder head dowel pins and oil control jet must be aligned.
    4.  

  2.  
  3. Replace the cylinder head using clean or new bolts and tighten the cylinder head bolts in two progressive steps and in the proper sequence. First, to 22 ft. lbs. (30 Nm) in sequence, then, to 43 ft. lbs. (60 Nm) in the same sequence.
  4.  



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Fig. Fig. 9: Cylinder head torque sequence-1984-87 engines

  1. Replace the timing belt and water pump pulleys and replace belt.
  2.  
  3. Replace the valve cover and tighten to 9 ft. lbs. (12 Nm) starting with the inner bolts then working out progressively. (Tighten CRX HF valve cover in proper two-step sequence whereby you apply low torque on the first round and apply final torque on second round -- see drawing).
  4.  



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Fig. Fig. 10: CRX HF valve cover torque sequence. Tighten to 9 ft. lbs. (12 Nm)



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Fig. Fig. 11: Replacing the timing belt pulley bolt. Be sure to tighten to the proper torque



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Fig. Fig. 12: Replace the belt making sure the teeth line up between the belt and pulley



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Fig. Fig. 13: The timing belt properly installed. Note that there is no "UP" mark on the top of this particular pulley, although there are opposed horizontal alignment marks enscribed on either side of the center bolt. These marks are sight lines that should be even with the top of the cylinder head as shown



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Fig. Fig. 14: Replacing the timing belt pulley cover-tighten the 6 x 1.0mm bolt to 7 ft. lbs. (10 Nm)

  1. Replace the breather chamber to intake manifold hose. Replace the thermostat housing-to-intake manifold hose.
  2.  
  3. Replace the exhaust manifold using a new gasket and clean or new bolts coated lightly with anti-seize compound.
  4.  
  5. Reconnect the header pipe to the exhaust manifold using a new gasket.
  6.  
  7. Install the distributor aligning it to the mating end of the end of the camshaft.
  8.  
  9. On fuel injected models, connect the engine sub-harness connectors and the following couplers from the cylinder head and the intake manifold.

    The four injector couplers
     
    The TA sensor connector
     
    The ground connector
     
    The TW sensor connector
     
    The throttle sensor connector
     
    The crankshaft angle sensor coupler
     
    The oxygen sensor coupler
     

  10.  

  1. Replace all other related hoses including: radiator, charcoal canister-to-control box, fuel lines, brake booster vacuum tube.
  2.  
  3. If equipped with A/C, replace the idle control solenoid hoses.
  4.  
  5. If a California or HI ALT model, replace the air jet controller.
  6.  
  7. Reconnect the throttle cable to carbureter or fuel injector throttle body (as applicable).
  8.  
  9. Replace all remaining wires, including: spark plug wires, engine ground wires, wires to the fuel cut-off solenoid valve, automatic choke, and the thermosensor.
  10.  
  11. Tighten the fuel system connections to the proper torque in order to accomodate fuel pressure when running.
  12.  
  13. Replace the air cleaner, refill the radiator and reconnect the negative battery terminal.
  14.  
  15. After installation, check to see that all hoses and wires are installed correctly and nothing was overlooked.
  16.  

If you took photographs before starting, now compare the before to after results if necessary.

  1. Run the engine and check the ignition timing. Check for coolant or oil leaks.
  2.  



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Fig. Fig. 15: Using a torque wrench to tighten cylinder head bolts to the proper specification

1988-91 Engines

See Figures 16, 17, 18 and 19



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Fig. Fig. 16: Cylinder head and components-1988-91 engines



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Fig. Fig. 17: Components that must be disconnected for cylinder head removal

  1. Be sure the engine is cold. Disconnect the negative battery cable. Drain the coolant.
  2.  
  3. Remove the brake booster vacuum hose from the brake master cylinder power booster. Remove the engine secondary ground cable from the valve cover.
  4.  
  5. Remove the air intake hose and the air chamber. Relieve the fuel pressure. Disconnect the fuel hoses and fuel return hose.
  6.  
  7. Remove the air intake hose and resonator hose. Disconnect the throttle cable at the throttle body. On vehicles equipped with automatic transaxles, disconnect the throttle control cable at the throttle body.
  8.  
  9. Disconnect the charcoal canister hose at the throttle valve.
  10.  
  11. Disconnect the following engine wire connectors from the cylinder head and the intake manifold:
    1. 14-prong connector from the main wiring harness.
    2.  
    3. EACV connector.
    4.  
    5. Intake air temperature sensor connector.
    6.  
    7. Throttle angle sensor connector.
    8.  
    9. Injector connectors.
    10.  
    11. Ignition coil from the distributor.
    12.  
    13. Top dead center/crank sensor connector from the distributor.
    14.  
    15. Coolant temperature gauge sender connector.
    16.  
    17. Coolant temperature sensor connector.
    18.  
    19. Oxygen sensor.
    20.  

  12.  
  13. Disconnect the vacuum hoses and the water bypass hoses from the intake manifold and throttle body.
  14.  
  15. Remove the upper radiator hose and the heater hoses from the cylinder head.
  16.  
  17. Remove the PCV hose, charcoal canister hose and vacuum hose from the intake manifold, and remove the vacuum hose from the brake master cylinder power booster.
  18.  
  19. Loosen the air conditioning idler pulley and remove the air conditioning belt. Remove the alternator belt. If equipped with power steering, remove the power steering belt and pump bracket.
  20.  
  21. Remove the intake manifold bracket. Remove the exhaust manifold bracket, then remove the header pipe.
  22.  
  23. Remove the exhaust manifold shroud, then remove the exhaust manifold.
  24.  
  25. Mark the position of the distributor in relation to the engine block, remove and tag the spark plug wires and remove the distributor assembly.
  26.  
  27. Remove the valve cover. Remove the timing belt cover.
  28.  
  29. Mark the direction of rotation on the timing belt. Loosen the timing belt adjuster bolt, then remove the timing belt from the camshaft pulley.
  30.  

Do not crimp or bend the timing belt more than 90 degrees or smaller than 1 in. (25mm) in diameter.

  1. Remove the cylinder head bolts. Once the bolts are all removed, remove the cylinder head along with the intake manifold from the engine. Remove the intake manifold from the cylinder head.
  2.  

To install:
  1. Be sure the cylinder head and the engine block surfaces are clean, level and straight and place a new head gasket on the mounting surface.
  2.  
  3. Be sure the UP mark on the timing belt pulley is at the top or the horizontal alignment marks are even with the top of the cylinder head when sighting with your eye looking straight-on.
  4.  
  5. Install the intake manifold making sure the cylinder head dowel pins and control jet are aligned. Starting with the inner nuts, tighten the nuts in a crisscross pattern in 2-3 steps to 17 ft. lbs. (23 Nm).
  6.  
  7. Install the bolts that secure the intake manifold to its bracket but do not tighten them at this point.
  8.  
  9. Position the cam correctly and install the cylinder head bolts.
  10.  
  11. Tighten the cylinder head bolts in two steps. On the first step tighten all the bolts, in sequence, to 22 ft. lbs. (30 Nm). On the final step, using the same sequence, tighten the bolts to 47 ft. lbs. (65 Nm).
  12.  
  13. On the Standard and Si vehicles, install the exhaust manifold and tighten the nuts in a crisscross pattern in two or three steps to 25 ft. lbs. (34 Nm) starting with the inner nuts.
  14.  
  15. On the CRX HF vehicles, install the catalytic converter to the exhaust manifold, then install the exhaust manifold assembly and tighten the bolts to 25 ft. lbs. (34 Nm).
  16.  
  17. Install the header pipe onto the exhaust manifold. Tighten the bolts to the intake manifold bracket. Install the header pipe on to its bracket.
  18.  
  19. After the installation procedure is complete, check that all tubes, hoses and connectors are installed correctly. Adjust the valve timing.
  20.  

If you took photographs before starting, now compare the instalation with the "before" pictures; correct any unintended discrepancies.



Click image to see an enlarged view

Fig. Fig. 18: Cylinder head torque sequence-1988-91 vehicles except CRX HF



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Fig. Fig. 19: Cylinder head torque sequence-1988-91 vehicles CRX HF

1992-95 Engines

See Figures 20 through 27

Be sure to inspect the timing belt before removing the cylinder head. Turn the crankshaft pulley so that the number one cylinder is at top dead center. Mark all emission hoses before disconnecting them. Be sure you have the original radio code number before disconnecting the battery (if applicable). This procedure does not require removing the engine from the vehicle.

  1. Be sure the engine is cold to avoid warping the cylinder head (wait until the coolant temperature drops below 100°F (38°C) before loosening the retaining bolts). Disconnect the negative battery cable. Drain the cooling system and relieve the system fuel pressure.
  2.  


CAUTION
Never smoke or allow open flame or spark near the car when working on the fuel system. Only drain fuel into an approved container.

  1. Remove the brake booster vacuum hose from the brake master cylinder power booster. Remove the engine secondary ground cable from the valve cover.
  2.  

An instant camera (if available) to take a few pictures of everything in place could prove invaluable when it is time for re-installation.

  1. Remove the air intake hose and the air chamber. Relieve the fuel pressure. Disconnect the fuel feed hose and evaporative emission control canister (EVAP control) hose from the intake manifold.
  2.  
  3. Remove the throttle cable at the throttle body (A/T only).
  4.  

Do not bend the throttle cable when removing it. If it gets kinked, replace with a new one.

  1. Remove the fuel return hose and brake booster vacuum hose.
  2.  
  3. Disconnect the charcoal canister hose at the throttle valve.
  4.  
  5. Disconnect the following engine wire connectors from the cylinder head and the intake manifold:
    1. Four injector connectors
    2.  
    3. Intake air temperature (IAT) sensor connector
    4.  
    5. Throttle position sensor connector
    6.  
    7. Manifold absolute pressure (MAP) sensor connector
    8.  
    9. Ground terminal (at thermostat cover)
    10.  
    11. Heated oxygen sensor (HO2s) connector
    12.  
    13. Engine coolant temperature (ECT) sensor connector
    14.  
    15. ECT switch connector
    16.  
    17. ECT gauge sending unit connector
    18.  
    19. VTEC solenoid valve connector (D16Z6, D15Z1 engines)
    20.  
    21. VTEC pressure switch connector (D16Z6, D15Z1 engines)
    22.  
    23. Exhaust gas recirculation (EGR) valve lift sensor connector (D15Z1 engine)
    24.  
    25. TDC/CKP/CYP sensor connector
    26.  

  6.  
  7. Remove and tag the spark plug wires and remove the distributor assembly. Remove the engine ground cable on the cylinder head cover.
  8.  
  9. Remove the power steering (P/S) belt and pump but do not disconect the P/S hose. Remove the P/S bracket.
  10.  
  11. Remove the emission vacuum hoses and water bypass hoses from the intake manifold assembly.
  12.  
  13. Remove the upper radiator hose and heater hose from the cylinder head and the water bypass hose from the thermostat housing.
  14.  



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Fig. Fig. 20: Location of hoses that must be removed for cylinder head removal

  1. Remove the intake manifold bracket.
  2.  
  3. Remove self-locking nuts and disconnect the the exhaust manifold bracket, then remove exhaust pipe A (formerly known as the "header pipe"). Then remove the exhaust manifold bracket.
  4.  
  5. Remove the PCV hose, remove the cylinder head cover, then remove the upper cover.
  6.  
  7. Loosen the adjusting bolt 1/2 turn.
  8.  



Click image to see an enlarged view

Fig. Fig. 21: The timing belt is released when the tensioner is loosened slightly and pushed to allow slack for the belt

  1. Push the tensioner to release tension from the timing belt, then re-tighten the adjusting bolt.
  2.  
  3. Remove the timing belt.
  4.  

Do not crimp or bend the timing belt more than 90 degrees or smaller than 1 inch (25mm) in diameter.

  1. Remove the cylinder head bolts in sequence as shown in accompanying drawing. Once the bolts are all removed, gently pry the cylinder head with a suitable tool and remove it along with the intake manifold from the engine. Remove the intake manifold from the cylinder head.
  2.  



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Fig. Fig. 22: Cylinder head bolt loosening sequence-1992-95 vehicles



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Fig. Fig. 23: Pry the head from the block using a suitable prytool

To install:
  1. Scrape any remaining gasket material from the mating surfaces and install a new head gasket. Be sure to pay attention to the following points:
    1. The No. 1 cylinder must be at top dead center with the camshaft pulley UP mark (if applicable, see further along in this section for timing belt replacement) on top before positioning the head in place.
    2.  
    3. Make sure the oil control orifice is not clogged (D15B7, D15B8 engines).
    4.  

  2.  
  3. Install the intake manifold using a new gasket and clean or new hardware and tighten the nuts in a crisscross pattern in two or three steps beginning with the inner nuts. Final tightening should be to 17 ft. lbs. (23 Nm).
  4.  



Click image to see an enlarged view

Fig. Fig. 24: Exploded view of intake manifold installation and proper torque figures. Tighten the bolts in the sequence described in step No. 20-1992-95 vehicles

  1. Install the exhaust manifold using a new gasket and clean or new hardware and tighten the nuts in a crisscross pattern in two or three steps beginning with the inner nuts. Final tightening should be to 16 ft. lbs. (22 Nm).
  2.  



Click image to see an enlarged view

Fig. Fig. 25: Exploded view of exhaust manifold mounting to cylinder head and proper torque figures-1992-95 D15B7 engine shown

  1. Install the three-way catalytic converter using all new hardware and gaskets on the exhaust manifold, then install the exhaust manifold assembly
  2.  



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Fig. Fig. 26: Exploded view of three-way catalytic converter-1992-95 D15Z1 and D15B8 engines for 49 states. The similar California version for same engines uses the same torque figures

  1. Install two dowel pins, a new head gasket and the cylinder head using clean or new oil-dipped bolts. Do not tighten fully yet.
  2.  
  3. Install the bolts that secure the intake manifold to its bracket, but do not tighten yet.
  4.  
  5. Now tighten the cylinder head bolts in the proper sequence in two steps:
    1. 1st step: initially tighten to 22 ft. lbs. (30 Nm)
    2.  
    3. 2nd step for D16Z6,D15Z1 engines: fully tighten to 53 ft. lbs (73 Nm), or
    4.  
    5. 2nd step for D15B7, D15B8 engines: fully tighten to 47 ft. lbs. (65 Nm)
    6.  

  6.  
  7. Install exhaust pipe A on the exhaust manifold.
  8.  
  9. Tighten the bolts for the intake manifold bracket and install exhaust pipe A on its bracket.
  10.  



Click image to see an enlarged view

Fig. Fig. 27: Exploded view of cylinder head mounting and various torque figures-1992-95 vehicles

  1. Replace the power steering (P/S) bracket and P/S pump tightening the bracket bolts to 33 ft. lbs. (45 Nm).
  2.  
  3. Reconnect all hoses, tubes and wire connectors as they were before removal.
  4.  

If you took photographs before starting, now compare the instalation with the "before" pictures; correct any unintended discrepancies.

  1. Install the timing belt.
  2.  
  3. Apply liquid gasket to the head mating surface of the No. 1 and No. 5 or No. 6 camshaft holders, then install the cylinder head cover and the spark plug wires.
  4.  
  5. Reconnect battery negative terminal and enter the 5-digit security code to re-activate the original radio (if so equipped).
  6.  

CLEANING AND INSPECTION



See Figures 28, 29 and 30

  1. Refer to the Valves, Removal and Installation procedure in this section and remove the valve assemblies from the cylinder head.
  2.  
  3. Using a small wire power brush, clean the carbon from the combustion chambers and the valve ports.
  4.  
  5. Inspect the cylinder head for cracks in the exhaust ports, combustion chambers or external cracks in the water chamber.
  6.  
  7. Thoroughly clean the valve guides using a suitable wire bore brush or expanding wire-type cleaner.
  8.  



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Fig. Fig. 28: Using an expanding wire cleaner to clean the valve guides

Excessive valve stem-to-bore clearance will cause excessive oil consumption and may cause valve breakage. Insufficient clearance will result in noisy and sticky functioning of the valve and will disturb engine smoothness.

  1. Measure the valve stem clearance as follows:
    1. Clamp a dial indicator on one side of the cylinder head rocker arm cover gasket rail.
    2.  
    3. Locate the indicator so movement of the valve stem from side-to-side (crosswise to the head) will cause a direct movement of the indicator stem. The indicator stem must contact the side of the valve stem just above the valve guide.
    4.  
    5. Prop the valve head about 1/16 in. (1.6mm) off the valve seat.
    6.  
    7. Move the stem of the valve from side-to-side using light pressure to obtain a clearance reading. If the clearance exceeds specifications, it will be necessary to ream (for original valves) the valve guides.

      Click image to see an enlarged view

      Fig. Fig. 29: Using a dial indicator to measure the valve stem clearance



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      Fig. Fig. 30: Measure the valve movement in the head using a dial indicator

    8.  

  2.  
  3. Inspect the rocker arm studs for wear or damage.
  4.  
  5. Install a dial micrometer into the valve guide and check the valve seat for concentricity.
  6.  

RESURFACING



See Figures 31 and 32

  1. Using a straightedge, check the cylinder head for warpage.
  2.  



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Fig. Fig. 31: Use a straightedge and feeler gauge to check for possible cylinder head warpage

  1. If the warpage exceeds 0.076mm in a 152mm span or 0.152mm over the total length, the cylinder head must be resurfaced. Resurfacing can be performed at most machine shops.
  2.  



Click image to see an enlarged view

Fig. Fig. 32: Use this pattern to check the cylinder head height

If the camshaft-to-holder oil clearances are not within specification, the cylinder head cannot be resurfaced.

 
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