Fig. 5.36. Removing the camshafts of the 1.6 l Duratec Ti-VCT engine: 1 – cylinder head; 2 – VCT support; 3 – camshaft bearing cap mounting bolts; 4 – camshaft bearing caps; 5 – camshafts.
The camshafts are replaced in the following cases: - the pressure in the engine lubrication system has dropped. The cause of this malfunction is often increased wear of the camshaft journals and camshaft bearing beds in the cylinder head.
When the beds and their covers wear out, the cylinder head is replaced as an assembly, since the beds are made directly in its body; - valve knocking with normal clearances in the valve drive mechanism. Caused by increased wear of the camshaft cams due to the use of low-quality motor oil or damage to the oil filter.
For replacing camshafts on a 1.6L Duratec Ti-VCT engineperform the following operations.
You will need: the same tools as for removing the timing belt and camshaft seals, as well as a TORX E11 key and a torque wrench.
1. Remove the VCT solenoid valves by disconnecting the wiring harness connectors from them and unscrewing one bolt each that secures them to the VCT caliper.
2. Remove the cylinder head cover (see Replacing the cylinder head cover gasket).
3. Remove the timing belt (see Checking and replacing the timing belt of the 1.6L Duratec Ti-VCT engine).
4. Remove the VCT mechanisms (see Replacing camshaft seals) and the VCT caliper (item 2 in Fig. 5.36), unscrewing the four bolts securing it to the cylinder head.
NOTE: The VCT caliper mounting bolts are of different lengths: those located further from the longitudinal axis of the cylinder head - 38 mm, closer to the axis - 51 mm.
NOTE: Do not mix them up when reinstalling.
5. Remove the 4 camshaft bearing caps by unscrewing the 3 bolts that secure them.
WARNING: The camshaft bearing caps are marked with their serial numbers.
WARNING: Remember or write down the location of the covers so that you can install them in their original places: the covers are processed together with the cylinder head and it is prohibited to depersonalize them.
WARNING: When installing, please note that the marks are on the outside of the covers.
6. Remove the camshafts.
7. Remove the oil seals from the camshaft journals.
NOTE: Replace the camshaft seals with new ones each time they are removed.
8. Inspect the camshafts. There should be no damage or wear on the threads in the holes for mounting the VCT mechanism. The surfaces of the bearing journals and cams should be well polished and without damage. No scoring, nicks, scratches, or aluminum drag from the bearing seats in the cylinder head are allowed on the working surfaces of the journals. If traces of seizure, overheating, deep scratches, or faceted wear are found on the working surfaces of the cams, replace the shafts.
WARNING: Grinding the camshaft lobes to eliminate stepped wear is prohibited, as changing the cam profile dimensions will disrupt the valve timing.
In workshops equipped with special tools and devices, you can check the radial runout of the camshaft journals. If the runout is more than 0.02 mm or the journals are not aligned, replace the shaft, since its straightening is not allowed.
9. Lubricate the camshaft beds with clean engine oil and place the camshafts in them in such a position that none of the cams rests with the highest part of its nose on the valve tappet adjusting washer.
10. Install the VCT caliper, having first applied sealant to its mating surface.
11. Install the camshaft bearing caps.
12. Clean the cover grooves and the mating surface of the cylinder head from the remains of the old gasket.
13. Tighten the camshaft bearing cap bolts in the order shown in Fig. 5.37, in three stages: 1st - tighten the bolts evenly by half a turn each until the bearing caps touch the cylinder head surfaces; 2nd – tighten to 7 Nm (0.7 kgf·m); 3rd – turn it 45°.
14. Press the camshaft seals into the VCT caliper sockets (see Replacing camshaft seals).
15. Install the remaining removed parts in the reverse order of removal.
For replacing camshafts of 2.0L and 2.3L Duratec-HE enginesperform the following operations.
You will need: the same tools as for removing the timing chain and camshaft seals, as well as a TORX E11 key and a torque wrench.
1. Remove the cylinder head cover (see Replacing the cylinder head cover gasket).
2. Remove the camshaft gears, tying a chain to them and securing them together with it to the edge of the timing cover.
3. Unscrew the camshaft bearing cap mounting bolts in the reverse order to that shown in Fig. 5.37.
Fig. 5.37. The order of tightening the bolts securing the camshaft bearing caps.
NOTE: Before removing the 2.3L Duratec-HE camshaft bearing caps, the variable valve timing solenoid must also be removed by disconnecting the wiring harness connector and removing the bolt securing it to the intake camshaft bearing cap.
4. Remove the camshaft bearing caps.
WARNING: The camshaft bearing caps are marked with their serial numbers.
WARNING: Remember or write down the location of the covers so that you can install them in their original places: the covers are processed together with the cylinder head and it is prohibited to depersonalize them.
WARNING: When installing, please note that the marks are on the outside of the covers.
5. Remove the camshafts.
6. Inspect the camshafts.
The surfaces of the bearing journals and cams must be well polished and without damage. No scoring, nicks, scratches, or aluminum drag from the bearing seats in the cylinder head are allowed on the working surfaces of the journals. If traces of seizure, overheating, deep scratches, or faceted wear are found on the working surfaces of the cams, replace the shafts.
WARNING: Grinding the camshaft lobes to eliminate stepped wear is prohibited, as changing the cam profile dimensions will disrupt the valve timing.
7. In workshops equipped with special tools and devices, you can check the radial runout of the camshaft journals. If the runout is more than 0.02 mm or the journals are not aligned, replace the shaft, since its straightening is not allowed.
8. Lubricate the camshaft beds with clean engine oil and place the camshafts in them in such a position that none of the cams rests with the highest part of its nose on the valve tappet adjusting washer.
9. Install the camshaft bearing caps.
10. Clean the cover grooves and the mating surface of the cylinder head from the remains of the old gasket.
11. Tighten the camshaft bearing cap bolts in the order shown in Fig. 5.37, in three stages: 1st - tighten the bolts evenly by half a turn each until the bearing caps touch the cylinder head surfaces; 2nd – tighten to 7 Nm (0.7 kgf·m); 3rd – turn it 45°.
12. Press the camshaft oil seals into the seats of the front camshaft bearing caps (see Replacing camshaft seals).
13. Install the remaining removed parts in the reverse order of removal.