Volkswagen Front Wheel Drive 1974-1989 Repair Guide

Cylinder Head

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REMOVAL & INSTALLATION



See Figures 1 through 10



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Fig. Fig. 1: Exploded view of the cylinder head found on 8-valve gasoline engines



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Fig. Fig. 2: Cylinder head found on 16-valve engines



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Fig. Fig. 3: Diesel engine cylinder head

Carbureted Engines

The engine should be cold before the cylinder head can be removed. The head is retained by ten socket head bolts and can be removed without removing the intake and exhaust manifolds.

Beginning in approximately July 1977, 12-point socket head bolts were used in place of the older 6-point version. These should be used in complete sets only and do not need to be retorqued after a mileage interval.

  1. Rotate the crankshaft to set the No. 1 cylinder at TDC. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove the air cleaner. Disconnect the fuel line from the carburetor.
  6.  
  7. Disconnect the radiator, heater, and choke hoses.
  8.  
  9. Label and unplug all electrical wires and emission control vacuum hoses. Remove the spark plug wires. The spark plugs can be left in the head if you choose to do so.
  10.  
  11. Remove the air conditioner compressor with lines attached and secure it out of the way. DO NOT disconnect any hoses or allow the unit to hang freely by the hoses.
  12.  
  13. Separate the exhaust manifold from the exhaust pipe.
  14.  
  15. Disconnect the EGR line from the exhaust manifold. Remove the EGR valve and filter from the intake manifold.
  16.  
  17. Remove the carburetor from the intake manifold.
  18.  
  19. Disconnect the air pump fittings.
  20.  
  21. Remove the timing belt cover and belt. Remove the camshaft cover and gasket.
  22.  
  23. Loosen the cylinder head bolts in the reverse order of the tightening sequence (refer to the illustration).
  24.  
  25. Remove the bolts and lift the cylinder head straight off.
  26.  
  27. Clean the head and block surfaces thoroughly and check the flatness of the cylinder block with a feeler gauge and a metal straight edge. Refer to the cleaning and inspection procedures in this section.
  28.  

To install:
  1. Install the new cylinder head gasket. If printed with the words TOP or OBEN, make sure these are facing upwards. Lower the head onto the gasket.
  2.  
  3. Install bolts 10 and 8 first. These holes are smaller and will properly position the gasket and cylinder head.
  4.  
  5. Install the remaining bolts. Tighten them in three stages using the tightening sequence shown in the illustration. Cylinder head tightening torque is 54 ft. lbs. (75 Nm). If equipped with 12-point bolts, tighten to 54 ft. lbs. (73 Nm), then tighten them 1 / 4 turn more.
  6.  
  7. Install and tension the timing belt. Install the timing belt and camshaft covers. Use a new gasket on the camshaft cover.
  8.  
  9. Connect the air pump fittings.
  10.  
  11. Install the carburetor with a new gasket.
  12.  
  13. Install the EGR valve and filter on the intake manifold. Connect the EGR valve line.
  14.  
  15. Connect the exhaust pipe to the exhaust manifold with a new gasket.
  16.  
  17. Mount the air conditioning compressor.
  18.  
  19. Connect the spark plug wires. Connect all the vacuum hoses and electrical wires.
  20.  
  21. Connect the choke, radiator and heater hoses.
  22.  
  23. Connect the fuel line to the carburetor. Install the air cleaner.
  24.  
  25. Fill the cooling system.
  26.  
  27. Connect the negative battery cable. Start the engine and check for leaks. Adjust the ignition timing and the idle speed.
  28.  

After approximately 1000 miles, the 6-point cylinder head bolts must be retorqued. Loosen them approximately 30 degrees, then tighten them to 54 ft. lbs. (75 Nm) on cold engines or 61 ft. lbs. (85 Nm) on hot engines (operating temperature). This is applicable to 6-point bolts only, 12-point bolts do not have to be retorqued.



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Fig. Fig. 4: A small extension can be used to reach the cylinder head bolts. The extra leverage of a breaker bar is also useful for loosening the bolts



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Fig. Fig. 5: After the bolts have been removed, carefully lift the cylinder head from the engine block



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Fig. Fig. 6: Always discard the old gasket. On diesel engines, make a note as to the number of identification notches on the edge of the gasket



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Fig. Fig. 7: New (12-point) and old (6-point) types of cylinder head bolts



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Fig. Fig. 8: Cylinder head tightening sequence for 4-cylinder engines. When removing the head, reverse the sequence



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Fig. Fig. 9: Cylinder head tightening sequence for 5-cylinder engines. When removing the head, reverse the sequence



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Fig. Fig. 10: Always torque the cylinder head bolts using the proper sequence, to the correct specification

Fuel Injected Engines

Special tools (VW 3140/1 and 2) are required for removing and installing the spring clamps securing the exhaust pipe to the manifold. This is a set of different sized wedges for spreading the spring clamps in steps. The installed spring clamp has considerable tension and could cause damage or injury if not properly removed. Clamps with wedges installed are under high tension and should be handled carefully.

Most fuel injected engines use 12-point socket head bolts in place of the older style 6-point bolts and do not require retorquing after any mileage interval. On Fox models, the head bolts may only be used once and should be replaced any time they are loosened or removed.

  1. Rotate the crankshaft until the No. 1 cylinder is at TDC. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove all the accessory drive belts.
  6.  
  7. Remove the alternator and, if required, the alternator mounting bracket.
  8.  
  9. Disconnect the air inlet ductwork from the throttle body assembly.
  10.  
  11. Label and disconnect all the emission control vacuum lines.
  12.  
  13. Disconnect the throttle cable from the throttle body assembly. On the 16-valve engines, remove the upper half of the intake manifold.
  14.  
  15. On vehicles with CIS/CIS-E fuel injection, remove the injectors and the cold start valve without disconnecting the fuel lines, then cap them. Secure all the lines aside.
  16.  
  17. On vehicles with Digifant II fuel injection, the injectors and fuel rail assembly may be left on the head. Disconnect the fuel supply and return lines and the wiring harness for the injectors.
  18.  
  19. Disconnect the radiator and heater hoses.
  20.  
  21. Remove the camshaft cover and gasket.
  22.  
  23. If equipped, remove the auxiliary air regulator from the intake manifold.
  24.  
  25. Label and unplug all electrical connections on the cylinder head. Remove the spark plugs.
  26.  
  27. Remove the bolts securing the air conditioner compressor, then tie it off to the side and out of the way. DO NOT disconnect any lines or allow the compressor to hang freely.
  28.  
  29. On 16-valve engines, remove the distributor with the cap and wires as an assembly.
  30.  
  31. Disconnect the exhaust pipe from the exhaust manifold. If the pipe is secured to the manifold with spring clamps:
    1. Push the exhaust pipe to one side and insert the longer starter wedge into the opposite clamp.
    2.  
    3. Push the pipe to the other side and install a wedge into the opposite clamp. Continue to work the pipe side to side while pushing the wedges into the clamps. The wedge must be inserted all the way to its shoulder.
    4.  
    5. Push the pipe to one side again, grasp the opposite clamp and wedge at the same time with locking pliers and remove them together. Leave the wedge in the clamp if it is going to be reinstalled. Place the clamps (with wedges installed) in a box until needed again.
    6.  

  32.  
  33. Remove the EGR line from the exhaust manifold, if equipped.
  34.  
  35. Remove the intake manifold.
  36.  
  37. Remove the timing belt covers and belt.
  38.  
  39. Loosen the cylinder head bolts in the reverse order of the tightening sequence (refer to the illustration).
  40.  
  41. Remove the bolts and lift the head straight off. Remove the old cylinder head gasket.
  42.  
  43. Clean the head and block surfaces thoroughly and check the flatness of the cylinder block with a feeler gauge and a metal straight edge. Refer to the cleaning and inspection procedures in this section.
  44.  

To install:
  1. Install the new cylinder head gasket. If printed with the words TOP or OBEN, make sure these are facing upwards. Lower the head onto the gasket.
  2.  
  3. Install bolts 10 and 8 first. These holes are smaller and will properly position the gasket and cylinder head.
  4.  
  5. Install the remaining bolts. Tighten them in three stages using the tightening sequence shown in the illustration. Cylinder head tightening torque is 54 ft. lbs. (75 Nm) for 6-point bolts. If equipped with 12-point bolts, the bolts should be tightened first to 29 ft. lbs. (40 Nm), then 43 ft. lbs. (60 Nm)., then an additional 180 degree turn (two 90 degree turns are permissible).
  6.  
  7. Install the timing belt and adjust the belt tension. Install the timing belt covers.
  8.  
  9. Install the intake manifold with new gaskets.
  10.  
  11. Connect the EGR pipe to the exhaust manifold, if equipped.
  12.  
  13. Connect the exhaust pipe to the manifold. On 16-valve engines, use new gaskets and self-locking nuts. Torque to 18 ft. lbs. (25 Nm). On models with spring clamps, push the pipe to one side and install the clamp. Push the pipe the other way to install the other clamp and continue to work the pipe side to side to remove the wedges.
  14.  
  15. Install the air conditioning compressor.
  16.  
  17. Connect all electrical wires. Install the spark plugs.
  18.  
  19. Install the auxiliary air regulator onto the intake manifold, if equipped.
  20.  
  21. Install the camshaft cover with a new gasket.
  22.  
  23. Connect all emission control vacuum lines.
  24.  
  25. Connect the radiator and heater hoses.
  26.  
  27. Install the fuel injection equipment and connect the wiring.
  28.  
  29. On 16-valve engines, install the upper intake manifold and the distributor.
  30.  
  31. Connect and adjust the throttle cable.
  32.  
  33. Connect the air inlet ductwork to the throttle body.
  34.  
  35. Install the alternator mounting bracket and alternator as required.
  36.  
  37. Install the accessory drive belts and adjust the belt tension.
  38.  
  39. Fill the cooling system.
  40.  
  41. Connect the negative battery cable. Start the engine and check for leaks. Adjust the ignition timing and the idle speed.
  42.  

After approximately 1000 miles, the 6-point cylinder head bolts must be retorqued. Loosen them approximately 30 degrees, then tighten them to 54 ft. lbs. (75 Nm) on cold engines or 61 ft. lbs. (85 Nm) on hot engines (operating temperature). This is applicable to 6-point bolts only; 12-point bolts do not have to be retorqued.

Diesel and Turbo Diesel Engines

The engine should be cold when the head is removed to avoid chances of warpage. Diesel cylinder heads cannot be resurfaced. The older 6-point socket head bolts are not interchangeable with the newer 12-point head bolts nor are their major engine components (engine block, cylinder head and gasket). The 6-point bolts were used up to March of 1982 and the 12-point bolts were used intermittently starting in April of 1981. The 12-point head bolts are not reusable and must always be replaced anytime they are removed.

  1. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove the air cleaner and duct.
  6.  
  7. Disconnect the fuel (injector) lines. Cap the ends of the lines to prevent the entry of dirt into the fuel system.
  8.  
  9. Label and disconnect all electrical wires and leads.
  10.  
  11. If equipped, disconnect and plug all lines coming from the brake booster vacuum pump, then remove the pump.
  12.  
  13. Disconnect the air supply tubes (turbo diesels only), then unbolt and remove the intake manifold.
  14.  
  15. Disconnect and plug all lines coming from the power steering pump, then remove the pump.
  16.  
  17. On turbo diesels, disconnect and remove the oil supply and return lines from the turbocharger.
  18.  
  19. Remove the exhaust manifold heat shields (if equipped). Remove the glow plugs and the fuel injectors.
  20.  
  21. Separate the exhaust pipe from the exhaust manifold or turbocharger, then remove the manifold.
  22.  
  23. Disconnect all radiator and heater hoses where they are attached to the cylinder head, then position them out of the way.
  24.  
  25. Remove the timing belt cover and the timing belt. Refer to the procedures in this section.
  26.  
  27. Remove the PCV hose.
  28.  
  29. Remove the camshaft cover.
  30.  
  31. Loosen the cylinder head bolts in the reverse order of the tightening sequence.
  32.  
  33. Remove the bolts and lift the cylinder head straight off.
  34.  

If the head sticks, tap it upward with a soft rubber mallet. Do not force anything between the head and the engine block to pry it upward; this may result in damage to the gasket seating surfaces.

  1. Clean the head and block surfaces thoroughly and check the flatness of the cylinder block with a feeler gauge and a metal straight edge. Refer to the cleaning and inspection procedures in this section.
  2.  

To install:

On these engines, the pistons actually project above the deck of the block. Depending upon the piston height, there are gaskets of different thicknesses which can be used to adjust piston-to-valve clearance. The gasket thickness is determined by the number of identification notches in the gasket. Be sure that the new gasket has the same number of notches as the gasket being replaced. If the pistons were removed or if the old gasket is not available, the piston height must be measured and a gasket selected from the measurement. Refer to the piston and connecting rod procedures in this section.

  1. Install the new cylinder head gasket. If printed with the words TOP or OBEN, make sure these are facing upwards. Lower the head onto the gasket.
  2.  
  3. Turn the crankshaft to TDC, then turn the crankshaft back until all the pistons are nearly equal height in the cylinders.
  4.  
  5. Place the cylinder head on the engine block and turn the camshaft gear so that the cam lobes for the No.1 cylinder point upwards. Install bolts No. 8 and 10 first. These holes are smaller and will properly locate the head on the engine block.
  6.  

Keep in mind that 12-point bolts cannot be reused. Always replace them!

  1. Install and hand tighten the remaining bolts.
  2.  
  3. On 6-point bolts, tighten the bolts using this procedure:
    1. Tighten the head bolts in numerical sequence to 35 ft. lbs. (50 Nm).
    2.  
    3. Tighten the head bolts in numerical sequence to 50 ft. lbs. (70 Nm).
    4.  
    5. Tighten the head bolts in numerical sequence to 65 ft. lbs. (90 Nm).
    6.  

  4.  
  5. On 12-point bolts, use this procedure to tighten the bolts:
    1. Tighten the head bolts in numerical sequence to 29 ft. lbs. (40 Nm).
    2.  
    3. Tighten the head bolts in numerical sequence to 43 ft. lbs. (60 Nm).
    4.  
    5. Finally, turn each head bolt an additional 1 / 2 (180 degree) turn in numerical sequence. Two 1 / 4 (90 degree) turns are permissible.
    6.  

  6.  
  7. Install the camshaft cover and the PCV hose.
  8.  
  9. Install the timing belt and its covers.
  10.  
  11. Connect all necessary heater and radiator hoses to the engine.
  12.  
  13. Connect the exhaust pipe to the turbocharger or the exhaust manifold.
  14.  
  15. Install the exhaust heat shields. Install the fuel injectors and glow plugs.
  16.  
  17. Connect the oil supply and return lines to the turbocharger. Refer to the turbocharger procedures in this section.
  18.  
  19. Install the power steering pump.
  20.  
  21. Install the intake manifold. Connect the air supply tubes on turbo diesels.
  22.  
  23. Connect all necessary wires and vacuum hoses.
  24.  
  25. Connect the fuel injector lines.
  26.  
  27. Install the air cleaner and duct. Fill the cooling system.
  28.  
  29. Change the engine oil and replace the oil filter.
  30.  
  31. Connect the negative battery cable. Start the engine and run it to normal operating temperature. Check for leaks.
  32.  

Be sure the engine is at normal operating temperature when retightening the bolts.

  1. Remove the camshaft cover. On 6-point bolts, retighten the head bolts in numerical order to 65 ft. lbs. (90 Nm). On 12-point bolts, turn the bolts in numerical order an additional 1 / 4 turn (90 degrees). The bolts should be tightened in one movement without loosening them first. This applies to both 6 and 12-point bolts.
  2.  
  3. Install the camshaft cover. Correct any leaks observed earlier.
  4.  

After 1,000 miles (1,609 km), the cylinder head bolts must be retorqued. The engine may be cold or warm. On 6-point bolt heads, loosen the bolts in the reverse of the tightening sequence about 30 degrees, then tighten them to 65 ft. lbs. (90 Nm). On 12-point bolt heads, tighten the bolts an additional1/4(90 degrees) in numerical order (do not loosen them first). The bolts should be tightened in one movement.

CLEANING AND INSPECTION



See Figures 1 and 2

  1. Remove the manifolds and all other items that can be unbolted or unscrewed.
  2.  
  3. Place the head on wooden blocks and remove the camshaft, cam followers and end seals.
  4.  

Keep the cam followers and bearing shells in order. Tag them so they can be installed in the same location.

  1. Working in a clean area, use spray solvent or brush cleaning solvent on the cylinder head top, sides and combustion chamber surfaces to remove any grease, dirt or oil, and help soften carbon deposits. After cleaning with solvent, wash the head with hot water and wipe dry.
  2.  
  3. Turn the head so the combustion chambers are facing up.
  4.  
  5. Before removing any carbon, examine the chambers and valve faces for obvious damage such as burnt valves or cracks. If one chamber is very clean, this usually indicates a coolant leak into that cylinder.
  6.  
  7. Mount a rotary wire carbon cleaning brush in an electric drill and clean the combustion chambers and valve heads. Be careful not to remove any aluminum or make deep scratches that may look like cracks. A complete inspection of the cylinder head (combustion chambers, valves, guides etc.) can be done after the valves and springs are removed.
  8.  
  9. To check the head for warping:
    1. Place a straight edge along the length of the head and attempt to slip a 0.004 inch (0.01mm) feeler gauge between them. Move the gauge the full length of the head and look for high or low spots.
    2.  
    3. Move the straight edge diagonally across the head and use the feeler gauge again.
    4.  
    5. If the head is warped more than allowed, use thicker feeler gages to determine how much and record the results. This information is needed to determine how much material to remove during resurfacing.
    6.  

  10.  



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Fig. Fig. 11: Checking the cylinder head flatness along the length of the head



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Fig. Fig. 12: Check the cylinder head flatness at both diagonals as well

RESURFACING



See Figure 13

If the cylinder head is warped more than 0.004 inches (0.01mm), it must be resurfaced. Diesel cylinder heads cannot be resurfaced because the relationship between the pre-chambers, injectors and head surface would be changed. If warped beyond specifications, diesel cylinder heads must be replaced.

To determine how much material can be removed from the cylinder head, measure the thickness of the head between the valve cover and head gasket surfaces. On 8-valve engines, the minimum cylinder head height is 5.22 inches (132.6mm). On 16-valve engines, minimum head height is 4.650 inches (118.1mm). Measure this dimension at several different points to determine the average thickness. These measurements are often best left for the machinist.



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Fig. Fig. 13: To determine how much material can be removed from the cylinder head, measure the thickness of the head between the valve cover and head gasket surfaces. Keep in mind that diesel cylinder heads cannot be resurfaced

If required, cylinder head resurfacing can be performed by most automotive machine shops.

 
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