2.3L V6: Diagnosis Mazda Millenia I facelift

Inspection

1. Remove intake manifold. See «INTAKE MANIFOLD»(ref-3917-S18799569532000052500000) under REMOVAL & INSTALLATION. Remove valve cover. Ensure engine is cold. Measure valve clearance between camshaft lobe and adjustment shim.
2. With engine at Top Dead Center (TDC), measure clearance at position "A". see scheme 2 Ensure clearance is.011-.012" (.27-.33 mm) for all measured valves. If clearance is not within specification, see «ADJUSTMENT»(ref-3917-S35459797602000052500000).
3. Rotate crankshaft 240 degrees clockwise, positioning No. 3 cylinder at TDC of compression stroke. Measure valve clearance at position "B". see scheme 2 Ensure clearance is within specification. If clearance is not within specification, see «ADJUSTMENT»(ref-3917-S35459797602000052500000).
4. Rotate crankshaft 240 degrees clockwise, positioning No. 5 cylinder at TDC of compression stroke. Measure valve clearance at position "C". see scheme 2 Ensure clearance is within specification. If clearance is not within specification, see «ADJUSTMENT»(ref-3917-S35459797602000052500000).

TROUBLE SHOOTING

To trouble shoot engine mechanical components, see appropriate table in TROUBLE SHOOTING article in GENERAL INFORMATION.

1. Inspect cylinder head for cracks or warpage at cylinder block and manifold areas. Resurface or replace cylinder head if warpage exceeds specification. See «CYLINDER HEAD»(ref-3917-S31334376842000052500000) table under ENGINE SPECIFICATIONS. Measure cylinder head bolt length. (Scheme 4) Replace cylinder head bolts if length is not 5.264-5.315" (133.7-135.0 mm).
2. Ensure cylinder head bolt holes are completely clean. Inspect cylinder block deck surface for warpage. Replace cylinder block if warpage exceeds specification. See «CYLINDER BLOCK»(ref-3917-S41835479622000052500000) table under ENGINE SPECIFICATIONS. Inspect camshaft and components. See «CAMSHAFT»(ref-3917-S06559165192000052500000).

Scheme 4

Scheme 5

Scheme 6

Scheme 7

1. Install NEW "O" ring onto oil control plugs. Coat "O" rings with engine oil. Install cylinder head gasket on cylinder block, paying attention to identification marks on head gaskets. (Scheme 5)
2. Ensure oil control plug "O" rings are coated with engine oil. Install cylinder head. Apply engine oil on cylinder head bolt threads and cylinder head bolt-to-cylinder head contact surfaces.
3. Install cylinder head bolts and tighten to specification in sequence. (Scheme 6) See «TORQUE SPECIFICATIONS»(ref-3917-S38585952592000052500000). After tightening head bolts to specification, put a paint mark on each head bolt. Using paint mark as a reference, further tighten head bolts 85-95 degrees in sequence, then tighten an additional 85-95 degrees. (Scheme 6)
4. Install rubber insulator on left cylinder head. Fit knock sensor harness through drill hole in block and pass under rubber insulator. (Scheme 7) Install camshafts using proper installation procedure. See «CAMSHAFT»(ref-3917-S06559165192000052500000). To install remaining components, reverse removal procedure.
5. Install camshaft pulleys, aligning timing marks with camshaft knock pins. Apply oil to threads and install camshaft lock bolts to specification. See «TORQUE SPECIFICATIONS»(ref-3917-S38585952592000052500000). Measure valve clearance. See «VALVE CLEARANCE ADJUSTMENT»(ref-3917-S15993686602000052500000) under ADJUSTMENTS.
6. Before installing valve cover and gasket, apply sealant at specified areas on cylinder head, then install rubber half-moon seals at end of cylinder heads. (Scheme 8) Apply sealant to valve cover where gasket contacts cover and over top of half moon seals in cylinder heads. Install gasket in valve cover. Install valve cover and gasket on cylinder head.
7. Install and tighten valve cover bolts to specification in sequence using several steps. (Scheme 9) See «TORQUE SPECIFICATIONS»(ref-3917-S38585952592000052500000). Install timing belt. See «TIMING BELT»(ref-3917-S12728635242000052500000). Install spacer at front of left cylinder head.
8. Install Lysholm compressor bracket bolts in sequence. (Scheme 10) Install Lysholm compressor and drive belt. Install throttle body assembly onto Lysholm compressor. Install front header pipe and right exhaust manifold. See «EXHAUST MANIFOLD»(ref-3917-S37688226212000052500000). see scheme 5

Scheme 8

Scheme 9

Scheme 10

1. Inspect timing belt for damaged teeth, cracking and oil contamination. Inspect timing belt auto tensioner for signs of oil leakage. Replace timing belt auto tensioner if oil leakage exists. Measure timing belt auto tensioner rod protrusion from end of rod to edge of the housing. (Scheme 11) Replace timing belt auto tensioner if distance is not.563-.594" (14.3-15.1 mm).
2. Oil leaking from the front of the engine on 1995-96 models may be caused by the No. 3 engine mount bracket stud. (Scheme 12) To repair the oil leak, remove No. 3 engine mount bracket. Remove mounting stud from engine. Clean all threads thoroughly. Apply Loctite PST Pipe Sealant with Teflon (No. 565) to stud threads. Install stud on engine block.

Scheme 11

Scheme 12

Inspect components for damage. Check camshaft journal diameter, lobe height and runout. Replace camshaft if any measurement is not within specification. See CAMSHAFT table under ENGINE SPECIFICATIONS.

Scheme 13

Scheme 14

1. Apply oil to camshaft journals, lobes and gears. Align camshaft gear timing marks. see scheme 19 Ensure camshaft bearing cap surfaces are clean on cylinder head. Install thrust bearing caps (with bolts) by hand, gradually in several steps. Apply sealant at designated areas on cylinder head. (Scheme 13) CAUTION: DO NOT allow sealant to contact camshaft. NOTE: Camshaft bearing caps on right cylinder head are identified by numbers, with No. 1 at timing belt end of engine. Camshaft bearing caps on left cylinder head are identified by letters, with "A" at timing belt end of engine.
2. Loosely install remaining camshaft bearing caps and bolts. Tighten camshaft bearing cap bolts to specification in sequence using several steps. (Scheme 14) See «TORQUE SPECIFICATIONS»(ref-3917-S38585952592000052500000). DO NOT let camshafts bind.
3. Lubricate NEW camshaft oil seal. Using hammer and suitable driver, tap camshaft oil seal into cylinder head. Apply sealant to NEW blind cap. Using soft-face hammer, tap blind cap into cylinder head.
4. Hold camshaft from turning by using a wrench on camshaft hex. Install left and right camshaft pulleys as identified by "L" and "R" stamp marks. Apply oil to camshaft pulley bolts. Tighten camshaft pulley bolts to specification. See «TORQUE SPECIFICATIONS»(ref-3917-S38585952592000052500000).
5. Measure valve clearance. See «VALVE CLEARANCE ADJUSTMENT»(ref-3917-S15993686602000052500000) under ADJUSTMENTS. Apply sealant at specified areas on cylinder head. (Scheme 8) Apply sealant on NEW valve cover gasket and install in valve cover. Install valve cover and gasket.
6. Install and tighten valve cover bolts to specification in sequence using several steps. (Scheme 9) See «TORQUE SPECIFICATIONS»(ref-3917-S38585952592000052500000). Rotate crankshaft so No. 1 cylinder is at TDC on compression stroke. Ensure timing mark on crankshaft pulley aligns with TDC mark on timing belt cover.
7. Install timing belt. See «TIMING BELT»(ref-3917-S12728635242000052500000). To install remaining components, reverse removal procedure. Tighten all fasteners to specification. See «TORQUE SPECIFICATIONS»(ref-3917-S38585952592000052500000). Fill and bleed cooling system. See «COOLING SYSTEM BLEEDING»(ref-3917-S40966717562000052500000) under REMOVAL & INSTALLATION.

Thermostat Inspection

1. Visually check that the thermostat valve is airtight.
2. Place the thermostat and a thermometer into water.
3. Heat the water and check the following: initial-opening temparature 176-183 degrees F (80-84 degrees C) Full-opem temperature 203 degrees F (95 degrees C) Fully open lift 0.33 in. (8.5 mm)

Scheme 15

1. Inspect components for damage. Ensure relief valve slides freely in bore. Install inner and outer rotors in oil pump body. Using feeler gauge, measure clearance between outer rotor and oil pump body. See «OIL PUMP SPECIFICATIONS»(ref-3917-S34219648742000052500000) table.
2. Measure rotor tip clearance between tips of both rotors. Place straightedge across oil pump body, above both rotors. Measure rotor end clearance between straightedge and rotor surface. Replace rotor assembly or oil pump body if any measurement exceeds specification.
3. Measure free length of spring for relief valve. Replace spring if free length is not 1.842" (46.79 mm).

OIL PUMP SPECIFICATIONS