Engine Mechanical - 3.5L: Diagnosis Nissan Altima L31

PRECAUTIONS FOR INSPECTION, REPAIR AND REPLACEMENT

1. Before repairing or replacing, thoroughly inspect parts. Inspect new replacement parts in the same way, and replace if necessary.

Inspection After Removal

The hot type spark plug is suitable when fouling occurs with the standard type spark plug under conditions such as

1. frequent engine starts
2. low ambient temperatures The cold type spark plug is suitable when engine spark knock occurs with the standard type spark plug under conditions such as
3. extended highway driving
4. frequent high engine revolution

Do not use a wire brush for cleaning.

If plug tip is covered with carbon, a spark plug cleaner may be used.

1. Cleaner air pressure: less than 588 kPa (6 kg/cm 2 , 85 psi)
2. Cleaning time: less than 20 seconds

Checking and adjusting plug gap is not required between change intervals.

1. Gap (nominal): 1.1 mm (0.043 in)

INSPECTION

Check for cracks and any excessive wear at the roller links of the timing chain. Replace the timing chain as necessary.

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1. Apply Genuine RTV Silicone Sealant or equivalent, to the rear timing chain case. Refer to «POSITION FOR APPLYING LIQUID GASKET»(ref-163530-S13436444312005050200000).
2. Align the rear timing chain case and water pump assembly with the dowel pins (RH and LH) on the cylinder block and install the case. Make sure the O-rings stay in place during installation. Tighten the mounting bolts in the numerical order as shown. There are two bolt lengths used. Follow the chart below for proper bolt length specifications. After all bolts are initially tightened, retighten them to the specification in the numerical order as shown. Rear timing chain case bolts: 12-13 N.m (1.2-1.4 kg-m, 9-10 ft-lb)
3. Install the timing chain tension guide.
4. Position the crankshaft so No. 1 piston is set at TDC on the compression stroke. Make sure that the knock pin hole, knock pin and crankshaft key are located as shown. Camshaft knock pin hole (intake side): at cylinder head upper face side in each bank. Camshaft knock pin (exhaust side): at cylinder head upper face side in each bank. Crankshaft key: at cylinder head side of RH bank. CAUTION: Hole on small diameter side must be used for intake knock pin. Do not misidentify (ignore big diameter side).
5. Install the crankshaft sprocket on the crankshaft. Make sure the mating marks on the crankshaft sprocket face the front of the engine.
6. Install the secondary timing chains and camshaft sprockets. CAUTION: Matching marks between the timing chain and sprockets slip easily. Confirm all matching mark positions repeatedly during the installation process. Push the sleeve of the secondary chain tensioner and keep it pressed in with a stopper pin. Align the matching marks on the secondary timing chain (gold link) with the ones on the intake and exhaust sprockets (stamped), and install them. Matching marks for the intake sprocket are on the back side of the secondary sprocket. There are two types of matching marks, round and oval types. They should be used for the RH and LH banks, respectively. RH bank: use round type. LH bank: use oval type. Align the knock pin and pin hole on the camshaft with the groove and knock pin on the sprocket, and install them. On the intake side, align the pin hole on the small diameter side of the camshaft front end with the knock pin on the back side of the camshaft sprocket, and install them. On the exhaust side, align the knock pin on the camshaft front end with the pin groove on the camshaft sprocket, and install them. Mounting bolts for the camshaft sprockets must be tightened in the next step. Tightening them by hand is enough to prevent the dislocation of the knock pins. It may be difficult to visually check the dislocation of mating marks during and after installation. To make the matching easier, make a mating mark on the sprocket teeth in advance with paint.
7. Install the secondary timing chain and sprocket to the other bank. Install the primary timing chain at the same time. Installation of the secondary timing chain follows the procedure in step 6. Install primary timing chain so the mating mark (punched) on camshaft sprocket is aligned with the yellow link on the timing chain, while the mating mark (notched) on the crankshaft sprocket is aligned with the orange one on the timing chain, as shown. When it is difficult to align mating marks of the primary timing chain with each sprocket, gradually turn the camshaft using a wrench on the hexagonal portion to align it with the mating marks. During alignment, be careful to prevent dislocation of mating mark alignments of the secondary timing chains.
8. After confirming the mating marks are aligned, tighten the camshaft sprocket mounting bolts. see scheme 91 Secure the camshaft using a wrench at the hexagonal portion to tighten the mounting bolts.
9. Pull the stopper pins out from the secondary timing chain tensioner.
10. Install the internal chain guide.
11. Install the slack guide. Do not overtighten the slack guide mounting bolts. It is normal for a gap to exist under the bolt seats when the mounting bolts are tightened to specification. see scheme 91
12. Install the timing chain tensioner for the slack guide. When installing the chain tensioner, push in the sleeve and keep it pressed in with the stopper pin. Remove any dirt and foreign materials completely from the back and the mounting surfaces of the chain tensioner. After installation, pull out the stopper pin by pressing the slack guide.
13. Reconfirm that the matching marks on the sprockets and the timing chain have not slipped out of alignment.
14. Install new O-rings on the rear timing chain case.
15. Install the front oil seal on the front timing chain case using a suitable tool. Apply clean engine oil to the oil seal edges.
16. Apply liquid gasket to front timing chain case. Refer to «POSITION FOR APPLYING LIQUID GASKET»(ref-163530-S13436444312005050200000). Before installation, wipe off the protruding sealant.
17. Install the rear case pin into dowel pin hole on front timing chain case.
18. Tighten bolts to the specified torque in order shown in the figure.
19. After installing the front timing chain case, check the surface height difference between the following parts on the oil pan mounting surface. If not within specification, repeat the installation procedure. Front timing chain case to rear timing chain case: (-0.14)-0.14mm [(-0.005] -0.0055 in] Oil pump to cylinder block: (-0.36) -(-0.10) mm [(-0.0142) -(-0.0039) in] Rear timing chain case to cylinder block: (-0.24)-0.14 mm [(-0.0094)-0.0055 in]
20. Install IVTC valve covers as follows: Install new O-rings on the front of the timing chain case. Install new seal rings on the IVTC valve covers. Apply RTV Silicone Sealant to the IVTC solenoid valve covers. Use genuine RTV Silicone Sealant, or equivalent. Refer to «RECOMMENDED CHEMICAL PRODUCTS AND SEALANTS»(ref-177331-S04337218152005052600000). Being careful not to move the seal ring from the installation groove, align the dowel pins on the chain case with the holes to install the IVTC solenoid valve covers. Tighten in the numerical order as shown.
21. Install the water pump cover and the chain tensioner cover. Apply RTV Silicone Sealant or equivalent. Refer to «RECOMMENDED CHEMICAL PRODUCTS AND SEALANTS»(ref-177331-S04337218152005052600000).
22. Install the RH and LH rocker covers. Rocker cover tightening procedure: Tighten the rocker cover bolts in two stages in the numerical order as shown. Stage 1: 0.96 - 2.96 N.m (0.1-0.3 kg -m, 9-26 in-lb) Stage 2: 7.33-9.33 N.m (0.75-0.95 kg-m, 65-82 in-lb)
23. Install the IVTC solenoid valve bank 1 and bank 2. IVTC solenoid: 10-12 N.m (1.0-1.3 kg-m, valve bolts 87-112 in-lb)
24. Install the engine oil dipstick.
25. Install the six spark plugs to their original positions. Spark plugs (6): 20-29 N.m (2.0-3.0 kg-m, 14-22ft-lb)
26. Install the six ignition coils to their original positions. Ignition coils (6): 6.37 - 7.54 N.m (0.65-0.76 kg-m, 57-66 in - lb)
27. Install the intake manifold collector. Tighten the bolts and nuts in numerical order as shown. Intake manifold: 18-21 N.m (1.8-2.2 kg-lb, collector bolts 13-15 ft-lb)
28. Connect the EVAP purge volume control solenoid hose.
29. Connect the PCV hose.
30. Connect the coolant hoses to the electric throttle control actuator.
31. Connect the power brake booster vacuum hose.
32. Connect the electric throttle control actuator harness electrical connector.
33. Install crankshaft pulley and tighten the bolt in two stages. Lubricate thread and seat surface of the bolt with new engine oil. Apply a paint mark for the second stage of angle tightening. Stage 1: 29-49 N.m (4.0-5.0 kg-m, 29-36 ft-lb) Stage 2: 60°-65° degrees clockwise
34. Remove the ring gear stopper.
35. Install the starter motor. Refer to «REMOVAL & INSTALLATION»(ref-152835-S38871372672003022800000).
36. Install the RH engine mount and bracket. Engine mount to frame bolts (2): 66-74 N.m (6.7-7.6 kg-m, 49- 54 ft- lb) Engine mount bracket to front cover bolts (2): 79-90 N.m (8.0-9.2 kg-m, 58-66 ft- lb) Engine mount bracket to front cover nut (1): 10-15 N.m (1.0-1.6 kg-m, 87-138 in-lb) Engine mount to bracket nuts (2): 49-58 N.m (5.0-6.0 kg-m, 37-43 ft-lb)
37. Reposition and reconnect the engine harness.
38. Install the alternator. Refer to «INSTALLATION»(ref-209053-S29747606782005120700000).
39. Install the power steering pump.
40. Install the A/C compressor and recharge the system. Refer to «MANUAL AIR CONDITIONER»(ref-206581).
41. Install the idler pulley and the drive belts. Refer to «CHECKING DRIVE BELTS»(ref-163530-S33901683802005050200000).
42. Install the inner fender splash shield and the engine undercovers.
43. Install the RH wheel and tire.
44. Install the fuel hose quick connector to the fuel tube at the vehicle piping side. Refer to «REMOVAL AND INSTALLATION»(ref-163530-S21666907452005050200000).
45. Install the engine coolant reservoir.
46. Install the intake air duct with the air cleaner case lid and mass air flow sensor.
47. Install engine cover.
48. Refill the engine with oil and coolant. CAUTION: Wait at least 30 minutes for the RTV Silicone Sealant to set before filling the engine with fluids to avoid leaks.
49. Install the battery.
50. Activate the fuel system. Check for any leaks when the system is repressurized and correct as necessary.
51. Start the engine and check all systems for leaks or improper operation. Correct as necessary. After starting engine, keep idling for three minutes. Then rev engine up to 3,000 RPM under no load to purge air from the high-pressure oil chamber of the chain tensioners. The engine may produce a rattling noise. This indicates that air still remains in the chamber and is not a matter of concern.

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1. Run the engine until it reaches normal operating temperature.
2. Turn the ignition switch to OFF.
3. Release fuel pressure and leave the fuel pump electrically disconnected. Refer to «FUEL PRESSURE RELEASE»(ref-135504-S01957061042002022200000) .
4. Remove all six spark plugs. Refer to «REMOVAL AND INSTALLATION»(ref-163530-S36140020622005050200000) .
5. Attach a compression tester to No. 1 cylinder.
6. Depress accelerator pedal fully to keep the electric throttle control actuator butterfly-valve wide open to maximize air intake flow.
7. Crank the engine and record the highest gauge indication.
8. Repeat the measurement on each cylinder (steps 5-7). Always use a fully-charged battery to obtain specified engine speed.
9. If compression in one or more cylinders is low: Pour a small amount of engine oil into cylinders through the spark plug holes. Retest compression (steps 5-8). If adding oil helps raise compression pressure, then the piston rings may be worn or damaged. If so, replace piston rings after checking piston. If the pressure stays low, a valve may be sticking or is seating improperly. Inspect and repair the valve and/or valve seat. Refer to «VALVE»(ref-163530-S40687404322005050200000) . If the valve and/or valve seat is damaged excessively, replace as necessary. If compression stays low in two or more cylinders that are next to each other: The cylinder head gasket may be leaking. Both cylinders may have valve component damage. Inspect and repair as necessary.

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1. Remove the timing chains. Refer to «REMOVAL»(ref-163530-S34037374582005050200000) .
2. Remove the fuel rail and injectors. Refer to «REMOVAL AND INSTALLATION»(ref-163530-S21666907452005050200000) .
3. Remove the intake manifold using power tool. Loosen the bolts in the numerical order as shown.
4. Remove the coolant outlet housing.
5. Remove rear timing chain case bolts using power tool. Loosen the bolts in the numerical order as shown.
6. Remove rear timing chain case using the Tool.
7. Remove the O-rings from the front of the cylinder heads. Discard the O-rings and use new O-rings for installation.
8. Remove the O-rings from the cylinder block. Discard the O-rings and use new O-rings for installation.
9. Remove the IVTC (intake valve timing control) valves. Discard the IVTC valve gaskets and use new gaskets for installation.
10. Remove the intake and exhaust camshafts and the camshaft brackets. Mark the camshaft brackets so they are placed in the same position and direction for installation. Equally loosen the camshaft bracket bolts in several steps in the numerical order shown. NOTE: If replacing the oil seals only, without removing the cylinder head, follow the steps below. Use method A or Method B to hold the valve in place while removing the component parts, so the valve does not fall into the combustion chamber. Method A: Without removing the cylinder head, set the piston being worked on to TDC to prevent the valve from falling into the combustion chamber. Method B: Without removing the cylinder head, remove the spark plug from the head, then install an air hose adapter into the spark plug hole and apply air pressure of 490 kPa (5 kg/cm2, 71 psi), as shown. The air pressure will hold the valve in place. This method will only work if the valves and valve seats are in good condition, if not, use Method A. Remove the valve lifters. Mark the lifters so they are installed in their original position if being reused. Compress the valve spring with the Tool and remove the following components: Valve collet Valve spring retainer Valve spring Valve spring seat With suitable pliers, remove the valve oil seal and replace it.
11. Remove the RH and LH cylinder head bolts, with power tool. The bolts should be loosened gradually in three stages. Loosen the bolts in the numerical order as shown.
12. Remove cylinder heads and gaskets. Discard the cylinder head gaskets and use new gaskets for installation.

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1. Before installing the rear timing chain case, remove the old RTV Silicone Sealant from mating surface using a scraper. Also remove old sealant from mating surface of cylinder block. Remove the old RTV Silicone Sealant from the bolt hole and thread.
2. Before installing the front cam bracket, remove the old RTV Silicone Sealant from the mating surface using a scraper. Do not scratch the mating surface.
3. Turn the crankshaft until No. 1 piston is set at TDC on the compression stroke. The crankshaft key should line up with the right bank cylinder center line as shown.
4. Install new gaskets on the cylinder heads. Do not rotate crankshaft and camshaft separately or valves will strike piston heads.
5. Inspect the cylinder head bolts before installing the cylinder heads. CAUTION: Cylinder head bolts are tightened by degree rotation tightening method. Whenever the size difference between d1 and d2 exceeds the limit, replace the bolts with new ones. Limit (d1 - d2): 0.11 mm (0.0043 in) Lubricate threads and seat surfaces of the bolts with new engine oil.
6. Install the cylinder heads on the cylinder block. Tightening procedure: Stage a: 98 N.m (10 kg-m, 72 ft-lb) in order Stage b: Loosen all bolts in the reverse order of tightening. Stage c: 34.3 - 44.1 N.m (3.5 - 4.4 kg-m, 26 - 32 ft-lb) Stage d: Turn all bolts 90° - 95° degrees clockwise Stage e: Turn all bolts 90° - 95° degrees clockwise
7. Install camshaft chain tensioners on both sides of cylinder head. Camshaft chain: 7 - 10 N.m (0.7 - 1.0 kg-m, tensioner bolts 62 - 89 in-lb)
8. Install exhaust and intake camshafts and camshaft brackets. Intake camshaft has a drill mark on camshaft sprocket mounting flange. Follow your identification marks made during removal, or follow the identification marks that are present on the new camshaft components for proper placement. Position the camshafts: RH exhaust camshaft dowel pin at about 10 o'clock. LH exhaust camshaft dowel pin at about 2 o'clock.
9. Before installing camshaft brackets, apply sealant to mating surface of No. 1 journal head. Use Genuine RTV Silicone Sealant, or equivalent. Refer to «RECOMMENDED CHEMICAL PRODUCTS AND SEALANTS»(ref-177331-S04337218152005052600000) . Refer to «POSITION FOR APPLYING LIQUID GASKET»(ref-163530-S13436444312005050200000) . Install camshaft brackets in their original positions and direction. Align the stamp marks as shown. If any part of valve assembly or camshaft is replaced, check and adjust the valve clearance. Refer to «Valve Clearance»(ref-163530-S18021023242005050200000) . Valve clearance (cold) Intake: 0.26 - 0.34 mm (0.010 - 0.013 in) Valve clearance (cold) Exhaust: 0.29 - 0.37 mm (0.011 - 0.015 in) Lubricate the threads and seat surfaces of the camshaft bracket bolts with new engine oil before installation. Tighten the camshaft brackets in the following four steps.
10. Install the IVTC solenoid valves with new gaskets. IVTC solenoid valve bolts: 10 - 12 N.m (1.0 - 1.3 kg-m, 87 - 112 in-lb)
11. Install the new O-rings on the cylinder block.
12. Install the new O-rings on the cylinder head.
13. Apply sealant to the specified portion of the rear timing chain case. Refer to «Precautions for Liquid Gasket»(ref-163530-S34092382182005050200000) . Before installation, wipe off the protruding sealant.
14. Align rear timing chain case with dowel pins, then install on cylinder head and block.
15. Tighten rear chain case bolts in two stages. Tighten bolts in numerical order shown. Retighten bolts in numerical order shown.
16. Install the coolant outlet housing.
17. Install the intake manifold with a new gasket. Tighten the bolts in the numerical order as shown. Stage 1: 5 - 10 N.m (0.5 - 1.0 kg-m, 44 - 86 in-lb) Stage 2: 26 - 31 N.m (2.7 - 3.2 kg-m, 20 - 23 ft-lb)
18. Install the fuel rail and injectors. Refer to «Removal and Installation»(ref-163530-S21666907452005050200000) .
19. Install the timing chains. Refer to «Installation»(ref-163530-S38848944172005050200000) .

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Inspection After Installation

1. Before starting engine, check the levels of coolant, lubrications, working oils, and of air conditioner refrigerant. If less than required quantity, fill to the specified level.
2. Run engine to check for unusual noise and vibration.
3. Warm up engine thoroughly to make sure there is no leakage of coolant, lubricants, oil, fuel, or exhaust gas.