Nissan Micra Cylinder Head Valve Guide Replacement - Service Manual EM-12
Step-by-step cylinder head valve-guide replacement procedure with heating, pressing and reaming steps and finished-size specs.
This is page EM-12 of a factory service manual engine mechanical (EM) section covering cylinder head valve guide replacement, continued from an inspection procedure. The page gives a four-step procedure: (1) heat the cylinder head to 150–160°C (302–320°F) and drive out the old valve guide with a press [under 20 kN (2t, 2.2 US ton, 2.0 Imp ton) pressure] or a hammer and suitable tool; (2) ream the cylinder head valve guide hole; (3) reheat the head to 150–160°C (302–320°F) and press the service valve guide into the cylinder head, with the guide installed to protrude 12.7–13.3 mm (0.500–0.524 in); and (4) ream the new valve guide to a finished inner size of 7.005–7.020 mm (0.2758–0.2764 in). Five illustrations (figure references SEM008A, SEM647, SEM541, SEM542, SEM007) show heating the head in an oil bath, driving out the guide, reaming the guide hole, the installed-height dimension, and reaming the new guide. The page was uploaded to a 1990 Nissan Micra gallery; the page itself does not state model or year applicability.
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Frequently asked questions
- To what temperature must the cylinder head be heated to remove or install the valve guide?
- Heat the cylinder head to 150 to 160°C (302 to 320°F) both to drive out the old valve guide and to press in the service valve guide.
- How much press pressure is used to drive out the valve guide?
- Drive out the valve guide with a press under a 20 kN (2t, 2.2 US ton, 2.0 Imp ton) pressure, or use a hammer and suitable tool.
- What is the finished reamed size of the new valve guide?
- After installation, ream the valve guide to a finished size of 7.005 - 7.020 mm (0.2758 - 0.2764 in).
- How far should the valve guide protrude when pressed into the cylinder head?
- The illustration shows an installed guide dimension of 12.7 - 13.3 mm (0.500 - 0.524 in).
- What are the steps for replacing a valve guide?
- 1) Heat the head to 150-160°C and drive out the old guide with a press or hammer; 2) ream the cylinder head valve guide hole; 3) reheat the head and press in the service valve guide; 4) ream the new guide to finished size 7.005-7.020 mm.
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