Valve Guide Replacement Acura MDX I

Valve Guide Replacement

Special Tools Required

1. Valve guide driver, 5.5 mm 07742-0010100
2. Valve guide reamer, 5.5 mm 07HAH-PJ7A100

Scheme 188

Scheme 189

Scheme 190

Scheme 191

Scheme 192

1. Inspect valve stem-to-guide clearance (see «VALVE STEM-TO-GUIDE CLEARANCE INSPECTION»(/acura/mdx/i-2000-2006/remont/mechanical/#cylinder-head) ).
2. Use a commercially available air-impact valve guide driver (A) modified to fit the diameter of the valve guides (Scheme 189) In most cases, the same procedure can be done using the special tool and a conventional hammer.
3. Select the proper replacement guides, and chill them in the freezer section of a refrigerator for about an hour.
4. Use a hot plate or oven to evenly heat the cylinder head to 300°F (150°C). Monitor the temperature with a cooking thermometer. Do not get the head hotter than 300°F (150°C); excessive heat may loosen the valve seats.
5. Working from the camshaft side, use the driver and an air hammer to drive the guide about 2 mm (0.1 in.) towards the combustion chamber. This will knock off some of the carbon and make removal easier. Hold the air hammer directly in line with the valve guide to prevent damaging the driver. Wear safety goggles or a face shield.
6. Turn the head over, and drive the guide out toward the camshaft side of the head.
7. If a valve guide still won't move, drill it out with a 8 mm (5/16 in.) bit, then try again. NOTE: Drill guides only in extreme cases; you could damage the cylinder head if the guide breaks.
8. Take out the new guide(s) from the freezer, one at a time, as you need them.
9. Apply a thin coat of new engine oil to the outside of the new valve guide. Install the guide from the camshaft side of the head; use the special tool to drive the guide to the specified installed height (A) of the guide (B). If you have all 12 guides to do, you may have to reheat the head. Valve Guide Installed Height Intake: 21.20-22.20 mm (0.835-0.874 in.) Exhaust: 20.63-21.63 mm (0.812-0.852 in.)
10. Coat both the reamer and the valve guide with cutting oil.
11. Rotate the reamer clockwise the full length of the valve guide bore.
12. Continue to rotate the reamer clockwise while drawing it from the bore.
13. Thoroughly wash the guide in detergent and water to remove any cutting residue.
14. Check the clearance with a valve (see «VALVE STEM-TO-GUIDE CLEARANCE INSPECTION»(/acura/mdx/i-2000-2006/remont/mechanical/#cylinder-head) ). Verify that a valve slides in the intake and exhaust valve guides without resistance or getting stuck.
15. Inspect the valve spring, if necessary renew the valve seat using a valve cutter (see «VALVE SEAT RECONDITIONING»(/acura/mdx/i-2000-2006/remont/mechanical/#cylinder-head) ).

Scheme 193

Scheme 194

Scheme 195

Scheme 196

1. Inspect valve stem-to-guide clearance (see «VALVE STEM-TO-GUIDE CLEARANCE INSPECTION»(/acura/mdx/i-2000-2006/remont/mechanical/#cylinder-head) ). If the valve guides are worn, replace them (see «VALVE GUIDE REPLACEMENT»(/acura/mdx/i-2000-2006/remont/mechanical/#cylinder-head__valve-guide-replacement) ) before cutting the valve seats.
2. Renew the valve seats in the cylinder head using a valve seat cutter.
3. Carefully cut a 45° seat, removing only enough material to ensure a smooth and concentric seat.
4. Bevel the upper edge of the seat with the 30° cutter and the lower edge of the seat with the 67.5° cutter (intake seat) or the 60° cutter (exhaust seat). Check the width of the seat and adjust accordingly.
5. Make one more very light pass with the 45° cutter to remove any possible burrs caused by the other cutters. Valve Seat Width Standard (New): 1.25-1.55 mm (0.049-0.061 in.) Service Limit: 2.00 mm (0.079 in.)
6. After resurfacing the seat, inspect it for even valve seating. Apply Prussian Blue compound (A) to the valve face. Insert the valve in its original location in the head, then lift it and snap it closed against the seat several times.
7. The actual valve seating surface (B) (Scheme 196)by the blue compound, should be centered on the seat. If it is too high (closer to the valve stem), you must make a second cut with the 67.5° cutter (intake seat) or the 60° cutter (exhaust seat) to move it down, then one more cut with the 45° cutter to restore seat width. If it is too low (closer to the valve edge), you must make a second cut with the 30° cutter to move it up, then one more cut with the 45° cutter to restore seat width. NOTE: The final cut should always be made with the 45° cutter.
8. Insert the intake and exhaust valves in the head, and measure the valve stem installed height (A). Intake Valve Stem Installed Height Standard (New): 46.75-47.55 mm (1.841-1.872 in.) Service Limit: 47.80 mm (1.882 in.) Exhaust Valve Stem Installed Height Standard (New): 46.68-47.48 mm (1.838-1.869 in.) Service Limit: 47.73 mm (1.879 in.)
9. If the valve stem installed height is over the service limit, replace the valve and recheck. If it is still over the service limit, replace the cylinder head; the valve seat in the head is too deep.