Cylinder head – removal, inspection and installation
Warning: Make sure the engine is completely cool before beginning this procedure. Warning: Diesel fuel is flammable, so take extra precautions when you work on any part of the fuel system. Don’t smoke or allow open flames or bare light bulbs near the work area, and don’t work in a garage where a gas-type appliance (such as a water heater or a clothes dryer) is present. Since diesel fuel is carcinogenic, wear fuel-resistant gloves when there’s a possibility of being exposed to fuel, and, if you spill any fuel on your skin, rinse it off immediately with soap and water. Mop up any spills immediately and do not store diesel fuel-soaked rags where they could ignite. When you perform any kind of work on the fuel system, wear safety glasses and have a Class B type fire extinguisher on hand.
Removal
1. Disconnect the cables from the negative terminals of the batteries (see Engine electrical systems).
2. Drain the coolant (see Tune-up and routine maintenance).
3. Disconnect the exhaust pipe from the turbocharger.
4. Remove the viscous fan and drive assembly (see Cooling, heating and air conditioning systems).
5. Install an engine support fixture or attach a hoist to the engine. Raise the engine enough to take weight from the engine mounts, then remove the through-bolt from the right engine mount. Remove the engine mount.
6. Detach the turbo oil drain fitting from the bottom of the turbocharger. Seal the openings to prevent contamination.
7. Disconnect the wiring from the air intake temperature sensor, then remove the air filter housing and snorkel. Tape the open turbo port to prevent contamination.
8. Disconnect the heater hoses from the head and the pipe.
9. Disconnect the oil supply line and the coolant lines from the turbocharger. Seal the openings to prevent contamination.
10. Remove the EGR cooler (see Tune-up and routine maintenance).
11. Unbolt the exhaust manifold and remove it with the turbo attached.
12. Remove the fan and shroud assembly (see Cooling, heating and air conditioning systems).
13. Remove the drivebelt (see Tune-up and routine maintenance).
14. Remove the fan support from the engine block.
15. Remove the top mounting bolt from the alternator. Loosen the lower bolt, then lower the alternator away.
16. Disconnect the upper radiator hose from the engine.
17. Label and disconnect all wiring that attaches to the cylinder head.
18. Remove the engine oil dipstick tube bolt.
19. Disconnect and remove the air intake housing.
20. Remove the pump-to-fuel rail line.
21. Remove the fuel rail-to-head lines and the fuel line shield.
22. On 2010 and later models, remove the fuel rail.
23. Remove the engine lift bracket from the back of the head.
24. On 2009 models, disconnect and remove the fuel filter assembly.
25. Remove the P-clip from the wiring harness behind the fuel filter housing.
26. Remove the valve cover (Valve cover – removal and installation).
27. Remove the injector harness nuts from the fuel injectors.
28. Remove the rockers, crossheads and pushrods (Rocker arms and pushrods – removal, inspection, installation and adjustment).
29. Remove the banjo bolt, sealing washers and the fuel line from the rear of the head.
30. Remove the fuel injectors (see Fuel and exhaust systems – diesel engine).
31. Remove the rocker housing and the gasket.
32. Using a new head gasket, make a template of the bolt hole locations on a piece of cardboard (see illustration). Loosen the head bolts, working in the order opposite that of the tightening sequence (see illustration 10.45). As each head bolt is removed, insert it into its location on the cardboard template.
10.32 Use a new head gasket to trace the bolt pattern on a piece of cardboard – punch holes for the head bolts and use the cardboard to keep track of the locations of the bolts
33. Make a thorough inspection of the head for any wiring harnesses and/or ground cables that might still be attached to the head. Make sure that all components have been removed or detached from the head. When you’re sure that nothing more is attached to the head, carefully pry on a casting protrusion between the head and the block to break the head gasket seal. The cylinder head is very heavy, so have an assistant help you lift it off the engine. If an assistant is not available, reattach the lift bracket to the rear of the head, attach an engine lifting hoist to the lifting brackets at the front and rear of the cylinder head and lift out the head. Warning: Do NOT attempt to remove the head by yourself!
Inspection
34. The cylinder head is a vital part of the engine’s efficiency. If you have gone to the trouble to remove it – to replace the head gasket, for example – and the engine has accumulated many, many miles, consider having the valves and seats refaced at an automotive machine shop to restore full sealing of the valves.
35. Remove the fuel injectors and rocker housing from the cylinder head. Note: Fuel injector removal requires special tools. The fuel injectors can be removed after the cylinder head is removed and set on the work bench. Have the injectors removed by a dealer service department or other diesel specialist equipped with the proper tools.
36. The mating surfaces of the cylinder head and block must be perfectly clean when the heads are installed. Gasket removal solvents are available at auto parts stores and may prove helpful.
37. Use a gasket scraper to remove all traces of carbon and old gasket material (see illus tration), then wipe the mating surfaces with a cloth saturated with brake system cleaner. If there is oil on the mating surfaces when the head is installed, the gasket may not seal correctly and leaks may develop. When working on the block, fill the cylinders with shop rags to keep debris out of the engine. Use a vacuum cleaner to remove any debris that falls into the cylinders. Note: Clean any carbon from the injector nozzle seats with a brass or nylon brush.
10.37 Use a gasket scraper and gasket removing solvent to clean the cylinder head and block sealing surfaces
38. Check the block and head mating surfaces for nicks, deep scratches and other damage. If imperfections are slight, they can be removed with emery cloth. If excessive, machining may be the only alternative. Use a straightedge and feeler gauge to check the cylinder head for warpage. If it is not within Specifications, the head must be machined to restore flatness. Consult with an automotive machine shop. Note: There is a raised pad at the rear of the cylinder head. There may be stampings there to indicate whether the head has been machined before. More than 0.010-inch removal may require valve regrinding as well. Consult with an automotive machine shop.
39. The block deck surface should also be checked for warpage by using a precision straightedge and feeler gauges. Compare your findings with the limits listed in this Chapter’s Specifications.
40. Use a tap of the correct size to chase the threads in the head bolt holes in the block. Mount each bolt in a vise and run a die down the threads to remove corrosion and restore the threads. Dirt, corrosion, sealant and damaged threads will affect torque readings. Measure the length of each cylinder head bolt, from under the bolt head to the end of the threads, comparing your measurements to the maximum bolt length. Most engine gasket sets will include a bolt stretch gauge for the head bolts (see illustration). If the head bolts are longer than the allowable length indicated on the gauge, they are stretched and must be replaced with new bolts.
10.40 A head bolt stretch gauge (included with the gasket set) is used to determine if the cylinder head bolts can be reused
41. If removed, have the rocker housing and fuel injectors reinstalled by the shop that removed them.
Installation
42. Position the new gasket over the dowels in the block (see illustration).
10.42 Position the new head gasket over the dowels in the block – note any markings on the gasket that indicate Top or Front
43. Carefully position the cylinder head on the block without disturbing the gasket.
44. Apply engine oil to the threads and underneath the bolt heads.
45. Install the bolts in their original locations and tighten them finger tight. Following the recommended sequence (see illustration), tighten the bolts in several steps to the torque listed in this Chapter’s Specifications.
10.45 Cylinder head bolt tightening sequence
46. The remainder of installation is the reverse of removal. Change the oil and filter and refill the cooling system (see Tune-up and routine maintenance).
47. Prime the fuel filter before attempting to start the engine (see Tune-up and routine maintenance).