Subaru Legacy BN/BS (2015-2019) Service Manual: Inspection
1. CYLINDER HEAD 1. Make sure that there are no cracks or other damages. Perform visual check, and use liquid penetrant tester on the important sections. Check that there are no marks of gas leaking or water leaking on gasket installing surface. 2. Set the cylinder head on ST.
3. Check for warpage at mating surface between the cylinder block and cylinder head using a straight edge (A) and thickness gauge (B). If the warpage exceeds limit, replace the cylinder head. Warping limit: 0.020 mm (0.0008 in) Standard height of cylinder head: 124±0.05 mm (4.88±0.0020 in) NOTE: Uneven torque for the cylinder head bolts can cause warpage. When reinstalling, pay special attention to the torque so as to tighten evenly.
2. VALVE SEAT Inspect the intake and exhaust valve seats, and correct the contact surfaces with a valve seat cutter if they are defective or when valve guides are replaced. Contacting width of valve seat W: Standard Intake 1.0 mm (0.039 in) Exhaust 1.5 mm (0.059 in)
3. VALVE GUIDE 1. Check the clearance between valve guide and valve stem. The clearance can be checked by measuring the outer diameter of valve stem with a micrometer and the inner diameter of valve guide with a caliper gauge respectively. Clearance between the valve guide and valve stem: Standard Intake 0.030 — 0.057 mm (0.0012 — 0.0022 in) Exhaust 0.040 — 0.067 mm (0.0016 — 0.0026 in) 2. If the clearance between valve guide and valve stem exceeds the standard, replace the valve guide or valve itself, whichever shows the greater amount of wear or damage. See the following procedure for valve guide replacement. Valve guide inner diameter: 5.500 — 5.512 mm (0.2165 — 0.2170 in) Valve stem outer diameters: Intake 5.455 — 5.470 mm (0.2148 — 0.2154 in) Exhaust 5.445 — 5.460 mm (0.2144 — 0.2150 in) (1) Place the cylinder head on ST1 with the combustion chamber upward so that valve guides fit the holes in ST1. (2) Insert the ST2 into valve guide and press it down to remove the valve guide.
(3) Turn the cylinder head upside down and place the ST as shown in the figure.
(4) Before installing a new valve guide, make sure that neither scratches nor damages exist on the inner surface of valve guide holes in cylinder head. (5) Put a new valve guide, coated with sufficient oil, in the cylinder head, and insert the ST1 into valve guide. Press in until the valve guide upper end is flush with the upper surface of ST2.
(6) Check the valve guide protrusion amount “L”. Valve guide protrusion amount L: Intake 8.6 — 9.0 mm (0.3386 — 0.3543 in) Exhaust 10.7 — 11.1 mm (0.4213 — 0.4370 in) (7) Ream the inside of valve guide using ST. Put the ST in valve guide, and rotate the ST slowly clockwise while pushing it lightly. Bring the ST back while rotating it clockwise.
NOTE: • Apply engine oil to the ST when reaming. • If the inner surface of valve guide is damaged, the edge of ST should be slightly ground with oil stone. • If the inner surface of valve guide becomes lustrous and the ST does not chip, use a new ST or remedy the ST. (8) After reaming, clean the valve guide to remove chips. (9) Recheck the contact condition between valve and valve seat after replacing the valve guide. 4. INTAKE AND EXHAUST VALVE 1. Check the flange and stem of the valve, and replace the valve with new one if damaged, worn, or deformed, “H” exceeds the standard, or if there is uneven wear. Head edge thickness H: Standard Intake (A) 1.0 mm (0.039 in) Exhaust (B) 1.2 mm (0.047 in)
2. Put a small amount of grinding compound on the valve seat surface, and lap the valve and valve seat surface. Install a new valve oil seal after lapping. NOTE: It is possible to differentiate between the intake valve and the exhaust valve by their overall length. Valve overall length: Intake 103.5 mm (4.075 in) Exhaust 103.2 mm (4.063 in) 5. VALVE SPRING 1. Check the valve springs for damage, free length, and tension. Replace the valve spring if it is not within the standard value presented in the table. 2. To measure the squareness of the valve spring, stand the valve spring on a surface plate and measure its deflection at the top of the spring using a try square.
6. INTAKE AND EXHAUST VALVE OIL SEAL 1. For the following, replace the oil seal with a new part. • When the lip is damaged. • When the spring is out of the specified position. • When readjusting the surfaces of valve and valve seat. • When replacing the valve guide. 2. Set the cylinder head on ST1. 3. Using the ST2, press in the oil seal.
NOTE: • Apply engine oil to oil seal before press-fitting. • When press-fitting the oil seal, do not use a hammer to strike in.
7. VALVE LIFTER 1. Check the valve lifter visually. 2. Measure the outer diameter of valve lifter. Outer diameter of valve lifter: 32.959 — 32.975 mm (1.2976 — 1.2982 in)
3. Measure the inner diameter of valve lifter mating surface on cylinder head. Inner diameter of valve lifter mating surface: 32.994 — 33.016 mm (1.2990 — 1.2998 in)
4. Check the clearance between valve lifter and valve lifter mating surface. The clearance can be checked by measuring the outer diameter of valve lifter and the inner diameter of valve lifter. If it exceeds the standard or offset wear occurs, replace the cylinder head. Valve lifter and valve lifter mating surface clearance: Standard 0.019 — 0.057 mm (0.0007 — 0.0022 in) | |||||||||||||||||||||||||||||||||
Installation
1. Apply liquid gasket to the mating surface of cylinder block shown in the figure.NOTE:• Install within 5 min. after applying liquid gasket.• Do not apply liquid gasket excessively. If to ...
Disassembly
1. Set the cylinder head on ST.ST 18250AA010CYLINDER HEAD TABLE2. Remove the valve lifter.3. Compress the valve spring using ST, and remove the valve spring retainer key, each valve and valve sprin ...
Other materials:
Removal
WARNING:Place “NO OPEN FLAMES” signs near the working area.CAUTION:Be careful not to spill fuel.1. Release the fuel pressure. Fuel > PROCEDURE2. Drain fuel. Fuel > PROCEDURE3. Open the fuel filler lid and remove the fuel filler cap.4. Turn the fuel filler pipe protector in the directio ...
