Honda Accord/Prelude 1984-1995 Repair Guide

Cylinder Head

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REMOVAL & INSTALLATION



Except Accord V-6

See Figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 11

The cylinder head temperature must be below 100°F (38°C); allow the engine to cool several hours if the car has been recently driven. Turn the crankshaft pulley so that the number one piston is at Top Dead Center (TDC) of the compression stroke.

  1. Disconnect the battery ground cable.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove the air cleaner and intake duct assembly.
  6.  
  7. Label and remove the brake booster, PCV and charcoal canister vacuum hoses from the intake manifold.
  8.  
  9. Remove the engine ground cable from the cylinder head or valve cover.
  10.  
  11. Relieve the fuel pressure using the proper procedure. Disconnect the fuel lines.
  12.  
  13. Disconnect the accelerator cable at the throttle body or carburetor. On automatic transaxle vehicles, also disconnect the throttle control cable.
  14.  
  15. Disconnect and tag all the wire harnesses and vacuum hoses from the cylinder head, intake manifold and throttle body/carburetor. Disconnect the spark plug wires, then position them aside.
  16.  
  17. Disconnect the upper radiator hose. Remove the heater hoses from the cylinder head.
  18.  
  19. If equipped, remove the cruise control actuator. Do not disconnect the cable; move the actuator out of the work area with the cable attached.
  20.  
  21. Remove accessory drive belts.
  22.  
  23. Disconnect the inlet hose from the power steering pump and plug the hose immediately to prevent fluid leakage. Remove the power steering pump from the cylinder head and position it aside.
  24.  

When the power steering hose is disconnected, the fluid will flow out. Cover the alternator with a shop towel to prevent the fluid from leaking into it.

  1. If the alternator is mounted to the cylinder head, remove it.
  2.  
  3. Remove the power steering and alternator brackets if they are mounted on the cylinder head.
  4.  
  5. Remove the distributor. Be sure to scribe a line relating the position of the distributor to the engine for easy installation.
  6.  
  7. If equipped, remove the cylinder sensor next to the distributor.
  8.  
  9. Remove the valve cover.
  10.  
  11. Remove the timing belt.
  12.  

Do not crimp or bend the timing belt.

  1. Remove the exhaust header pipe nuts and the header pipe bracket (if equipped). Pull the pipe away from the exhaust manifold.
  2.  
  3. If equipped, remove the EGR crossover and air suction pipes.
  4.  
  5. On Accords through 1989 and Preludes through 1991, the cylinder head can be removed with the intake and exhaust manifolds either still attached or removed. On other models, the manifolds should be removed first.
  6.  
  7. On some engines, it will be necessary to remove the camshaft holders, camshafts and rocker arms to access the cylinder head bolts. If so, refer to the proper procedures in this section.
  8.  
  9. Remove the cylinder head bolts in sequence (take notice of any bolt holes occupied by longer bolts). Failure to follow this procedure may cause the head to warp.
    1. On 1984-89 Accords and 1984-91 Preludes, work from the ends toward the center. Loosen each bolt about 1 / 2 turn each time and make several passes to release the tension evenly.
    2.  
    3. On 1990-95 Accords and 1992-95 Preludes, follow the loosening sequence shown in the illustrations. Loosen each bolt about 1 / 3 turn each time. Repeat the sequence until all bolts are loosened.

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      Fig. Fig. 1: Bolt loosening sequence on 1990-93 Accords and 1992-95 Preludes with 2.2L engines



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      Fig. Fig. 2: Bolt loosening sequence on 1992-95 Preludes with 2.3L engines



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      Fig. Fig. 3: Bolt loosening sequence on 1994-95 Accords

    4.  

  10.  
  11. Remove the cylinder head. The head may resist removal, even with the bolts out. Tap the edge of the head with a plastic or rubber mallet; lift the head straight up to remove it.
  12.  



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Fig. Fig. 4: A breaker bar is helpful for loosening the cylinder head bolts



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Fig. Fig. 5: Have an assistant help lift the cylinder head assembly off the engine

  1. Remove the cylinder head gasket and clean the mating surfaces.
  2.  



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Fig. Fig. 6: Never reuse the old gasket



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Fig. Fig. 7: Carefully use a scraper to remove any remaining gasket material



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Fig. Fig. 8: Always tighten the bolts with a torque wrench

  1. If applicable, remove the intake and exhaust manifolds from the cylinder head.
  2.  

To install:
  1. Install a new head gasket on the engine, making certain it is positioned correctly. The cylinder head dowel pins and the oil jet must be in place. Refer to the illustrations if necessary.
  2.  
  3. Install the head. Lower it straight down onto the block, aligning it correctly.
  4.  
  5. Apply clean engine oil to the bolt threads and the contact face of the bolt head. Install the head bolts finger-tight.
  6.  
  7. On all models except 1988-89 DOHC Prelude and 1992-95 Preludes with 2.3L and VTEC engines, tighten the head bolts following sequence A. On 1988-89 DOHC Preludes, use sequence B. Use sequence C on 1992-95 Preludes with 2.3L and VTEC engines.
    1. On 1984-89 Accords and 1984-91 Preludes, tighten the bolts in two passes. The first pass should bring the bolts to about 22 ft. lbs. (30 Nm). On the second pass, tighten the bolts to their final torque of 49 ft. lbs. (68 Nm).
    2.  
    3. On 1990-93 Accords, tighten the bolts to 29 ft. lbs. (40 Nm) on the first pass, 51 ft. lbs. (70 Nm) on the second pass, then tighten the bolts to their final torque of 78 ft. lbs. (108 Nm).
    4.  
    5. On 1994-95 Accords and 1992-95 Preludes, the bolts are also tightened in three passes. Tighten the bolts to 29 ft. lbs. (40 Nm) on the first pass, 51 ft. lbs. (70 Nm) on the second pass, then tighten the bolts to their final torque of 72 ft. lbs. (100 Nm).

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      Fig. Fig. 9: Cylinder head bolt torque sequence A



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      Fig. Fig. 10: Cylinder head bolt torque sequence B



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      Fig. Fig. 11: Cylinder head bolt torque sequence C

    6.  

  8.  
  9. If applicable, assemble the intake and exhaust manifolds to the head. Use new gaskets.
  10.  
  11. If applicable, install the cam, rockers and camshaft holders.
  12.  
  13. If equipped, install the EGR crossover and air suction pipes.
  14.  
  15. Connect the exhaust pipe to the manifold using new nuts.
  16.  
  17. Install the timing belt.
  18.  
  19. Install the valve cover.
  20.  
  21. Install the cylinder sensor (if equipped) and the distributor.
  22.  
  23. If applicable, install the alternator.
  24.  
  25. Install the power steering pump, then connect the inlet hose to the pump.
  26.  
  27. Install the accessory drive belts. Adjust the belt tensions.
  28.  
  29. Install the heater hoses.
  30.  
  31. Install the cruise control actuator if it was removed.
  32.  
  33. Connect the spark plug wires. Connect all the wire harnesses and vacuum hoses to the cylinder head, intake manifold and throttle body/carburetor.
  34.  
  35. Connect the throttle control cable and/or accelerator cable at the throttle body.
  36.  
  37. Connect the fuel lines.
  38.  
  39. Install the brake booster, PCV and charcoal canister vacuum hoses.
  40.  
  41. Install the air cleaner and intake duct.
  42.  
  43. Refill the engine coolant. It is recommended that the engine oil be changed whenever a cylinder head is removed.
  44.  
  45. Connect the negative battery cable.
  46.  
  47. Start the engine, allowing it to idle. Bleed the cooling system. Check the work area carefully for any signs of fluid leakage or any indication of the timing belt rubbing or slapping the covers.
  48.  

Accord V-6

See Figures 12, 13, 14, 15, 16 and 17

The cylinder head temperature must be below 100°F (38°C); allow the engine to cool several hours if the car has been recently driven. Turn the crankshaft pulley so that the number one piston is at Top Dead Center (TDC) of the compression stroke.

  1. Disconnect the battery ground cable.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove the air intake duct.
  6.  
  7. Disconnect the accelerator and cruise control cables from the throttle body. Loosen the locknuts, then slip the cable ends out of the linkage.
  8.  
  9. Detach the starter cable from the strut tower brace, then remove the brace.
  10.  
  11. Relieve the fuel pressure by loosening the service bolt on the top of the fuel filter about a turn. Disconnect the fuel feed hose from the filter. Remove the fuel return hose.
  12.  
  13. Label and disconnect all vacuum hoses from the throttle body, intake manifold and cylinder head.
  14.  
  15. Disconnect the water bypass hose from the throttle body.
  16.  
  17. Remove the accessory drive belts.
  18.  
  19. Disconnect the engine ground cable.
  20.  
  21. Remove the vacuum pipe assembly.
  22.  
  23. Support the engine with a floor jack on the oil pan (use a cushion between the jack and pan). Tension the jack so that it is just supporting the engine but not lifting it.
  24.  
  25. Remove the three mount bolts, then loosen the through-bolt. Pivot the side engine mount out of the way.
  26.  



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Fig. Fig. 12: Remove the three mount bolts and loosen the through-bolt to pivot the mount out of the way

  1. Disconnect the inlet hose from the power steering pump, then plug the hose and pump. Remove the power steering pump.
  2.  
  3. Remove the harness cover and ground cable from the water passage.
  4.  
  5. Label and disconnect all wiring harnesses from the cylinder head, intake manifold and throttle body.
  6.  
  7. Disconnect the spark plug wires from the cylinder head, then remove the distributor.
  8.  
  9. Remove the upper and lower radiator hoses, then the heater hoses.
  10.  
  11. Remove the Intake Air Bypass (IAB) vacuum tank.
  12.  
  13. Remove the water passage. Discard the O-rings.
  14.  
  15. Remove the harness covers from the intake manifold.
  16.  
  17. Remove the EGR crossover pipe.
  18.  
  19. Remove the intake manifold.
  20.  
  21. Remove the exhaust manifolds.
  22.  
  23. Remove the valve covers and side covers.
  24.  
  25. Remove the timing belt.
  26.  
  27. Remove the camshaft pulleys and back covers.
  28.  
  29. Remove the camshaft holder plates, camshaft holders and camshafts.
  30.  
  31. Remove the rocker arms, exhaust inner rocker arms and pushrods.
  32.  
  33. Remove the cylinder head bolts using the sequence shown in the illustration. Loosen each bolt about 1 / 3 turn each time. Repeat the sequence until all bolts are loosened. Failure to follow this procedure may result in cylinder head warpage.
  34.  



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Fig. Fig. 13: Loosen the cylinder head bolts in sequence to prevent warpage

  1. Clean the gasket mounting surfaces.
  2.  

To install:
  1. Install new head gaskets on the engine, making certain they are positioned correctly. The cylinder head dowel pins and the oil jets must be in place. Refer to the illustrations if necessary.
  2.  



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Fig. Fig. 14: Be sure the oil jets and dowel pins are positioned correctly

  1. Install the head. Lower it straight down onto the block, aligning it correctly.
  2.  
  3. Apply clean engine oil to the cylinder head bolts and washers.
  4.  
  5. Torque the cylinder head bolts (following the sequence in the illustration) in two progressive steps. First to 29 ft. lbs. (39 Nm), then to 56 ft. lbs. (76 Nm).
  6.  



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Fig. Fig. 15: Always tighten the bolts in sequence

  1. Pour clean engine oil into the cylinder head hydraulic tappet mounting holes, up to the level of the oil path. Also, pour clean engine oil into the fillers on the cylinder head (refer to the illustration).
  2.  
  3. Install the hydraulic tappets into the cylinder head. Do not rotate the hydraulic tappet while inserting it into the head.
  4.  



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Fig. Fig. 16: Pour clean engine oil into the fillers and tappet mounting holes



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Fig. Fig. 17: Do not rotate the hydraulic tappet while inserting it into the head

  1. Install the pushrods and rocker arms. Be sure to install each part in its original position. Loosen the rocker arm adjusting screws and locknuts before installation.
  2.  
  3. Install the camshafts and camshaft oil seals. Install the camshaft holders and plates (refer to the procedures in this section).
  4.  
  5. Install the back covers and camshaft pulleys. Tighten the back cover bolts to 9 ft. lbs. (12 Nm) and the pulley bolts to 23 ft. lbs. (31 Nm).
  6.  
  7. Install the timing belt.
  8.  
  9. Adjust the exhaust rocker arms. Refer to the Rocker Arm procedures in this section.
  10.  
  11. Install the side covers and valve covers.
  12.  
  13. Install the intake manifold.
  14.  
  15. Install the exhaust manifold.
  16.  
  17. Install the EGR crossover pipe.
  18.  
  19. Install the water passage with new O-rings. Tighten the bolts to 16 ft. lbs. (22 Nm).
  20.  
  21. Install the IAB vacuum tank. Tighten the bolts to 9 ft. lbs. (12 Nm).
  22.  
  23. Install the heater hoses, then the upper and lower radiator hoses.
  24.  
  25. Install the distributor. Connect the spark plug wires.
  26.  
  27. Connect the wiring harnesses to the intake manifold, cylinder head and throttle body as applicable.
  28.  
  29. Install the ground cable and harness cover at the water passage.
  30.  
  31. Install the power steering pump and connect the inlet hose.
  32.  
  33. Install the side mount (refer to the engine removal and installation procedure). Remove the jack supporting the engine.
  34.  
  35. Install the vacuum pipe assembly. Tighten the bolts to 9 ft. lbs. (12 Nm).
  36.  
  37. Install the engine ground cable.
  38.  
  39. Install, then tension the accessory drive belts.
  40.  
  41. Connect the water bypass hose to the throttle body.
  42.  
  43. Connect the vacuum hoses to the intake manifold, cylinder head and throttle body as applicable.
  44.  
  45. Connect the fuel lines. Use new gaskets.
  46.  
  47. Install the strut tower brace and attach the starter cable. Tighten the bolts to 16 ft. lbs. (22 Nm).
  48.  
  49. Connect the cruise control and accelerator cables to the linkage to the throttle body.
  50.  
  51. Install the air intake duct.
  52.  
  53. Refill the cooling system. It is recommended that the engine oil be changed whenever a cylinder head is removed.
  54.  
  55. Reconnect the battery ground cable. Start the engine and bleed the cooling system. Check for leaks.
  56.  

CLEANING AND INSPECTION



See Figures 18, 19, 20, 21 and 22

  1. Using a wire brush chucked into an electric drill, remove all the carbon from the combustion chambers in the head. Be careful not to scratch the valve seats.
  2.  



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Fig. Fig. 18: Using a wire brush chucked into an electric drill, remove all the carbon from the combustion chambers in the head

  1. Use a gasket scraper and remove all material from the manifold and head surfaces, again being careful not to scratch the surface.
  2.  
  3. Refer to the valve removal and installation procedures in this section and remove the valves from the cylinder head.
  4.  
  5. Use a valve guide brush or a fine-bristled rifle bore brush with solvent to clean the valve guides.
  6.  



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Fig. Fig. 19: Use a guide brush to clean the valve guides

  1. Use a clean cloth and a stiff bristle brush with solvent to thoroughly clean the head assembly. Make sure that no material is washed into the bolt holes or passages. If possible, dry the head with compressed air to remove fluid and solid matter from all the passages.
  2.  

Do not clean the head in a hot tank or chemical bath.

  1. Measure the valve stem clearance as follows:
    1. Mount 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. Install the valve (without the springs) and prop the valve head about 0.39 in. (10mm) 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 specification (refer to the valve specifications chart), it will be necessary to knurl or replace the valve guides.

      Click image to see an enlarged view

      Fig. Fig. 20: A dial indicator can be used to check the valve stem clearance



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      Fig. Fig. 21: Check for warpage across the head surface ...

    8.  

  2.  
  3. Check the camshaft journal oil clearance. If the clearance is greater than specified, check the total run-out and the journal diameters of the camshaft. If they are within specification, the cylinder head must be replaced. If they are out of specification, replace the camshaft, then recheck the oil clearances. If the oil clearances are still out of specification, the cylinder head must also be replaced.
  4.  
  5. With the head clean and dry, use a precision straightedge and a feeler gauge to measure the head for warpage. If it is less than 0.002 in. (0.05mm), resurfacing is not required. If warpage is between 0.002-0.008 in. (0.05-0.2mm), the head must be resurfaced. Any warpage in excess of this requires replacement of the head.
  6.  



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Fig. Fig. 22: ... as well as both diagonals

  1. If all is well with the head to this point, it is highly recommended that it be taken to a professional facility such as a machine shop for sophisticated crack testing. The various procedures are much more reliable than simple examination by eye. The cost is reasonable and the peace of mind is well worth the cost. If any cracks are found, the head must be replaced.
  2.  
  3. While the head is being checked, carefully scrape the carbon from the tops of the pistons. Don't scratch the metal of the piston tops and don't damage the cylinder walls. Remove all the carbon and fluid from the cylinder.
  4.  
  5. If repairs are needed to the valves, camshaft or other components, follow the appropriate procedures outlined in this section.
  6.  

RESURFACING



The Honda cylinder heads for all engines may be resurfaced by a reputable machine shop. Resurfacing is recommended if the engine suffered a massive overheating, such as from a failed head gasket.

The heads are manufactured to be as light as possible; consequently, there is not much excess metal on the face. Any machining must be minimal. If too much metal is removed, the head becomes unusable. A head which exceeds the maximum warpage specification CANNOT be resurfaced. The machine shop will have a list of minimum head thicknesses; at no time may this minimum be exceeded.

 
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