Reconditioning

General:
- Disassembly, assembly, and reconditioning procedures for the cylinder heads used on Volkswagen engines are similar to those for most other modern 4-cylinder, water-cooled engines with alloy cylinder heads. For anyone with the proper tools and equipment and basic experience in cylinder head reconditioning, this section provides the specifications and special reconditioning information necessary to repair these Volkswagen engines.
- Cylinder head reconditioning is not overly complicated, but it does require a variety of special equipment and skills. For those who are without the necessary tools, or unfamiliar with reconditioning procedures, this work may be best left to a professional automotive machinist. You will still find this information to be important to the qualified machinist who does the work. If machine shop services are not readily available, one alternative is to install a Volkswagen remanufactured cylinder head, available from an authorized Volkswagen dealer parts department.

CYLINDER HEAD ASSEMBLY:

Cylinder Head, Exploded View:

- Cylinder heads with small fine cracks between valve seats and plug threads are usable provided the cracks are not more than 0.5 mm (0.02 in.) wide and do not extend into more than the first few spark plug threads.

CAMSHAFT AXIAL CLEARANCE:

Checking Camshaft Axial Clearance:

- The image above shows a dial indicator setup used to check axial or end-to-end thrust clearance.
- To measure camshaft axial play, relieve the tension on the cam lobes by first removing the cam followers, and camshaft drive chains. Then reinstall four bearing caps (end caps only).

NOTE: Store hydraulic cam followers with the camshaft contact surface face down.

- Camshaft axial clearance (wear limit): 0.15 mm (0.006 in.).
- Lubricate the cam follower's contact surfaces before installing.

NOTE: Do not interchange camshaft bearing caps or cam followers. Note the bearing cap offset when installing. The beveled corners on the bearing caps face the intake side of the cylinder head.

Camshaft Chain Sprocket Timing Marks:

- When reinstalling the camshaft drive chain, marks on sprockets should align with each other and cylinder head top surface.
- Tightening torque for camshaft bearing caps (nuts): 15 Nm (11 ft lb).

CAMSHAFT RADIAL CLEARANCE:

- Check camshaft radial clearance, bearing clearance measured perpendicular to the camshaft, using Plastigage (R) or its equivalent.
- Remove valve lifters.
- Clean camshaft and cylinder head bearing surfaces.
- Camshaft lobes not touching valves or upper spring seats.

CAUTION: Do not turn the camshaft while the Plastigage (R) is in place. Remove all traces of Plastigage (R) from the cam journals and bearing surfaces before final assembly.

- Camshaft radial clearance (wear limit): 0.1 mm (0.004 in.).
- Bearing cap tightening torque:
Clearance check only: 20 Nm (15 ft lb).
Final assembly: 15 Nm (11 ft lb).

VALVES:

- Intake and exhaust valves cannot be refaced by machine. They must always be hand-lapped only.
- The exhaust valves are sodium filled to aid heat dissipation, and are dangerous when handled improperly. Special care must be taken to properly dispose of valves and avoid possible injury to others.

WARNING:
- Sodium-filled valves, when discarded, must be disposed of properly to avoid personal injury.
- Always wear protective goggles or glasses.
- Using a hand saw, cutoff the valve stern near the head of each valve, Do not use a power saw.
- Sodium reacts violently with water. Do not let any water contact the valve while cutting.
- Throw the valve parts (no more than 10 valves at a time) into a bucket of water and stand clear. Discard the valves when the reaction has ceased.

NOTE: Water used for disposal of sodium-filled valves is biodegradable and can be disposed of accordingly.

VALVE GUIDES:

- To properly recondition a worn cylinder head, the valve guides must be checked for wear. Valve guides should be replaced if necessary before machining the valve seats.

Checking:

Checking Valve Guide Wear:

- Check valve guides for wear by inserting a new valve and measuring side-to-side play. The valve should be inserted just far enough so that the end of the valve stem is flush with the guide.

NOTE: There are slight size differences between intake and exhaust. Use only intake valves to check intake guides, and exhaust valves for exhaust guides.

- Valve guide maximum play:
Intake: 1.0 mm (0.039 in.).
Exhaust: 1.3 mm (0.051 in.).

Removing and Installing:

NOTE: Inspect the valve seats to ensure that the cylinder head can be reconditioned before installing new valve guides.

Removing Valve Guides:

- The valve guides should be pressed out from the combustion chamber side of the cylinder head. The image above illustrates this step and identifies the appropriate Volkswagen special tools.

Valve Guide Installation:

- Replacement valve guides, with shoulders, are pressed in from the camshaft side of the cylinder head. The image above illustrates this step and identifies the appropriate Volkswagen special tools.
- Before installing new valve guides, coat them with oil first.
- maximum of one ton pressure after shoulder of guide seats in head.
- Remove and install guides with Volkswagen special tool 3121 (order no. T03 121 000 15 ZEL), then ream the guides to final size using Volkswagen special tool 3120 (order no. T03 120 000 15 ZEL) and an appropriate cutting oil.

NOTE: Volkswagen part numbers and special tool order numbers listed are for reference only. They are subject to change. Always check with your authorized Volkswagen dealer for the most accurate and up-to-date information.

VALVE SEATS:

- There is a limit to how much material can be removed when refacing valve seats. If the valve seats are cut too far, the final assembly will leave too little space for the hydraulic lifter to function properly. A calculation must be made before refacing the valve seats.

Measure Distance Between Top Of Valve & Top Surface Of Cylinder Head:

- Measure the distance between top of valve stem and top (gasket) surface of cylinder head, with the valve firmly seated, as shown in the image above. Then subtract the minimum dimension as listed below. The difference is the maximum allowable depth of cut for refacing. Remove only as much material as is required to get an acceptable seat.

- Minimum Dimension (valve stem to head):
Intake: 34.4 mm (1.354 in.).
Exhaust: 34.7 mm (1.366 in.).