Cylinder Head Assembly: Service and Repair
Removal
1. Disconnect battery ground cable and remove engine splash guard.
2. Remove air filter, preheat and inlet hose.
3. Disconnect crankcase breather and blow-off valve hose.
4. Label, disconnect and cap all electrical connectors, vacuum and fuel lines from cylinder head.
5. Disconnect front exhaust pipe from turbocharger assembly. If necessary, apply anti-rust oil to the attaching bolts.
6. Disconnect exhaust pipe from transmission and coupling brackets. Cover exhaust pipe opening with suitable tape.
7. Remove expansion tank cap.
8. On vehicles without drain tap, disconnect lower radiator hose and drain coolant.
9. On vehicles with drain tap, carefully loosen drain tap and drain coolant. Disconnect lower hose from radiator.
10. Disconnect lower hose form cold start unit, point hose end downward and drain remaining coolant.
11. Disconnect and cap oil feed and return lines from oil cooler and turbocharger assembly.
12. Disconnect upper radiator hose and cold start unit hose from cylinder head.
13. Loosen power steering pump attaching bolts and position pump aside. Do not disconnect power steering pump lines.
14. Remove vacuum pump and pump plunger. Position vacuum pump aside.
15. Remove fuel delivery lines from cylinder head.
16. Remove valve cover.
17. Remove front and rear timing belt covers.
Fig. 1 Engine at TDC and injection:
18. Set No. 1 cylinder to TDC and injection position (compression stroke). Both No. 1 cylinder camshaft lobes should be face upward at equal angles and the flywheel timing mark should be at zero (0), Fig. 1.
19. Remove cylinder head timing belt cover attaching screws.
20. Loosen water pump attaching bolts and release tension from timing belt tensioner.
21. Using tool 5199 or equivalent, to hold camshaft sprocket in place, loosen front camshaft sprocket attaching bolt. Using a suitable mallet, tap camshaft sprocket from camshaft. Remove sprocket and timing belt.
22. Loosen injection pump bracket attaching bolts to release belt tension. Leave one attaching bolts in place and lift off belt.
23. Using tool 5199 or equivalent, hold rear camshaft sprocket in place. Using tool 5201 or equivalent, loosen rear camshaft sprocket attaching bolt. While loosening attaching bolt, do not allow camshaft to rotate.
Fig. 2 Cylinder head bolt tightening sequence:
24. Carefully and gradually loosen cylinder head attaching bolts in reverse of tightening sequence shown in Fig. 2.
25. Carefully remove cylinder head from cylinder block. Ensure rear glow plug clears injection pump bracket and valves do not contact cylinder walls.
Installation
1. Place cylinder head on wooden blocks. Ensure cylinder head is not resting on valves.
2. Clean gasket surfaces on cylinder head and cylinder head bolt holes.
3. Check cylinder head for damage and/or warpage. Measure cylinder head for warpage lengthwise and crosswise. Cylinder head warpage measured lengthwise should not exceed .020 inch. Cylinder head warpage measured crosswise should not exceed .008 inch. Replace cylinder head if warpage measurements obtained exceed specifications.
4. If cracks are found, ensure cracks are no longer than .020 inch. If cracks exceed .020 inch, replace cylinder head.
5. If pistons, connecting rods and bearings are replaced, piston height must be measured and correct cylinder head gasket installed. If measured piston height above cylinder block is .032-.035 inch, a .059 inch thick cylinder head gasket (indicated by 2 notches on gasket) must be used. If measured piston height above cylinder block is .036-.040 inch, a .063 inch gasket (indicated by 3 notches on gasket) must be used.
6. Install cylinder head gasket onto cylinder block with ``UP'' marking facing upward. When installing a new gasket, ensure to check date code located on gasket and packet. The gasket must be used before the indicated date. Only gaskets with code designation M2 or later may be used on turbocharged engines (D24T engines). To avoid reducing the sealing properties of the gasket do not open gasket packet until just before gasket is to be installed. When installing, ensure not to damage the Teflon strip or rubber seal.
7. Place No. 1 cylinder to TDC. In this position the flywheel timing mark should be at zero (0).
8. Set camshaft so that No. 1 cylinder is at the injection position (both camshaft lobes pointing diagonally upward.)
9. Install tool 5190 or equivalent, to prevent camshaft from rotating.
10. Lubricate, then install new cylinder head bolts.
Fig. 2 Cylinder head bolt tightening sequence:
11. Torque all cylinder head bolts one at a time in sequence shown in Fig. 2 in four steps as follows:
a. First step, torque bolts to 29 ft. lbs.
b. Second step, torque bolts to 44 ft. lbs.
c. Third step, torque bolts to 55 ft. lbs.
d. Fourth step, angle tighten cylinder head bolts an additional 180° in one movement without stopping.
e. After the cylinder head and all removed engine accessories are installed, vacuum lines, fuel lines and electrical connectors properly connected and engine properly filled with correct coolant, start and operate engine until normal operating temperature has been obtained. With engine properly warmed, turn cylinder head bolts an additional 90 degrees.
12. Reverse remaining removal procedure to complete installation.