Cylinder Head Assembly: Service and Repair

Fig. 1 Cylinder Head Gasket Selection:

Fig. 2 Cylinder Head Bolt Tightening Sequence:

With the timing belt removed, avoid turning the camshaft or crankshaft. If movement is required, exercise extreme caution to avoid valve damage caused by piston contact. During the following procedure, the engine coolant must be drained completely and discarded. Refer to "Specifications for cooling system capacities. Do not reuse contaminated coolant.
1. Obtain audio coded anti-theft code, then disconnect battery ground cable. Remove air cleaner and intercooler duct assembly.
2. Identify cylinder head gasket thickness by noting part number (black arrow) or number of notches/holes (white arrow), Fig. 1
3. Remove expansion tank cap and drain cooling system by removing thermostat.
4. Disconnect all coolant hoses from cylinder head, then crankcase ventilation hoses which interfere with head removal.
5. Disconnect wiring harness connectors to temperature sensors and glow plugs, and remove wiring harness from cylinder head.
6. Disconnect and remove injector fuel pipe assemblies as a unit, then plug open fittings. Do not alter shape of fuel pipe assemblies.
7. If cylinder head is to be replaced, remove fuel injectors and glow plugs, then plug openings in cylinder head.
8. Note No. 3 injector contains needle lift sensor and must be installed into No. 3 cylinder.
9. Remove timing belt as outlined under "Timing Belt,Replace. Do not rotate crankshaft or camshaft with timing belt removed, as engine damage may result.
10. Raise and support vehicle. Disconnect exhaust pipe, oil drain lines and fittings from turbocharger, then lower vehicle.
11. Remove cylinder head retaining bolts in reverse order of tightening sequence, Fig. 2
12. Ensure hoses, cables and wiring harness components are disconnected from cylinder head and that camshaft is properly secured, then remove head.
13. Remove camshaft as outlined in "Camshaft, Replace.
14. Remove lifters, noting original position if cam or head is to be reused, then valves, valve springs and valve guide seals using a suitable valve spring compressor.
15. Check valve guides as outlined in "Valve Guides,Inspection."
16. Thoroughly clean cylinder head and check for cracks. Check gasket surface for flatness. Diesel engine cylinder heads cannot be resurfaced. If more than 0.004 inch warpage is measured, cylinder head must be replaced.
17. The following procedure is used only when engine block or components are replaced or original gasket thickness cannot be determined. Check piston deck height to determine head gasket thickness as follows:
a. Ensure TDC mark on flywheel is aligned with pointer, and measure piston projection using a dial indicator.
b. Select head gasket thickness according to next step. Cylinder head gaskets can be identified by part number and notches in edge of gasket. Install gasket with "OBEN marking toward cylinder head.
c. With piston projection 0.0260-0.0341 inch, one notch should be indicated, 0.0341-0.0356 inch, two notches should be indicated and with piston projection 0.0356-0.0402 inch, three notches should be indicated.
18. Install cylinder head gasket without sealer, ensure camshaft is locked and TDC mark on flywheel is properly aligned with pointer.
19. To aid in cylinder head and gasket alignment, insert guide pins from kit No. 3070, or equivalent, in outer holes on intake manifold side.
20. Mount cylinder head, insert bolts 1 through 7 and 9, Fig. 2 and tighten by hand.
21. Remove guide pins with tool from kit No. 3070, or equivalent, then install bolts 8 and 10.
22. Using sequence shown in Fig. 2 torque cylinder head bolts in four steps as follows (engine cold): first, to 30 ft. lbs.; second, to 44 ft. lbs.; third, tighten an additional 1/4 (90°) turn; and finally, tighten an additional 1/4 (90°) turn.
23. Reverse procedure to complete installation. Ensure injection pump timing is within specifications as outlined under "Injection Pump Timing.