
ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-31
Engine Diagnosis Table
Perform troubleshooting referring to following table when ECM (PCM) has detected no DTC and no abnormality
has been found in visual inspection and engine basic inspection previously.
Condition Possible Cause Correction
Hard starting
(Engine cranks OK)Faulty idle air control system “DIAG. FLOW TABLE B-4” in this
section.
Faulty ECT sensor or MAF sensor ECT sensor or MAF sensor in Sec-
tion 6E2.
Faulty ECM (PCM) Inspection of ECM (PCM) and its
circuit in this section.
Low compression Compression check in Section
6A2.
Faulty hydraulic valve lash adjuster Valve lash adjuster in Section 6A2.
Compression leak from valve seat Valves inspection in Section 6A2.
Sticky valve stem Valves inspection in Section 6A2.
Weak or damaged valve springs Valves spring inspection in Section
6A2.
Compression leak at cylinder head gasket Cylinder head inspection in Section
6A2.
Sticking or damaged piston ring Piston ring inspection in Section
6A2.
Worn piston, ring or cylinder Cylinders, pistons and piston rings
inspection in Section 6A2.
Malfunctioning PCV valve PCV system inspection in Section
6E2.
Engine has no power
Engine overheating Refer to “OVERHEATING” in this
table.
Defective spark plug Spark plugs in Section 6F2.
Faulty ignition coil with ignitor Ignition coil in Section 6F2.
Fuel pressure out of specification
(dirty fuel filter, dirty or clogged fuel hose or
pipe, malfunctioning fuel pressure regulator,
malfunctioning fuel pump)“DIAG. FLOW TABLE B-3” in this
section.
Maladjusted TP sensor installation angle TP sensor in Section 6E2.
Faulty EGR system “DTC P0400 DIAG. FLOW TABLE”
in this section.
Faulty injector Fuel injector in Section 6E2.
Faulty TP sensor, ECT sensor or MAF sensor TP sensor, ECT sensor or MAF
sensor in Section 6E2.
Faulty ECM (PCM) Inspection of ECM (PCM) and its
circuit in this section.
Low compression Refer to the same item in “HARD
STARTING” of this table.
Dragging brakes Diagnosis in Section 5.
Slipping clutch Diagnosis in Section 7C1.

6-1-34 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Poor gasoline mileage
Faulty spark plug (improper gap, heavy depos-
its, and burned electrodes, etc.)Spark plugs in Section 6F2.
Fuel pressure out of specification “DIAG. FLOW TABLE B-3” in this
section.
Faulty TP sensor, ECT sensor or MAF sensor TP sensor, ECT sensor or MAF
sensor in Section 6E2.
Faulty EGR system “DTC P0400 DIAG. FLOW TABLE”
in this section.
Faulty injector Fuel injector in Section 6E2.
Faulty ECM (PCM) Inspection of ECM (PCM) and its
circuit in this section.
Low compression Refer to the same item in “HARD
STARTING” of this table.
Poor valve seating Valves inspection in Section 6A2.
Dragging brakes Diagnosis in Section 5.
Slipping clutch Diagnosis in Section 7C1.
Thermostat out of order Thermostat in Section 6B.
Improper tire pressure Diagnosis in Section 3.
Excessive engine oil
consumptionSticky piston ring Piston cleaning in Section 6A2.
Worn piston and cylinder Cylinders, pistons and piston rings
inspection in Section 6A2.
Worn piston ring groove and ring Pistons and piston rings inspection
in Section 6A2.
Improper location of piston ring gap Pistons installation in Section 6A2.
Worn or damaged valve stem seal Valves and cylinder head in Sec-
tion 6A2.
Worn valve stem Valves inspection in Section 6A2.
Low oil pressure
Improper oil viscosity Engine oil and oil filter change in
Section 0B.
Malfunctioning oil pressure switch Oil pressure switch inspection in
Section 8.
Clogged oil strainer Oil pan and oil pump strainer clean-
ing in Section 6A2.
Functional deterioration of oil pump Oil pump in Section 6A2.
Worn oil pump relief valve Oil pump in Section 6A2.
Excessive clearance in various sliding parts “INSPECTION” for each parts in
Section 6A2. Condition Possible Cause Correction

6A2-6 ENGINE MECHANICAL (H27 ENGINE)
INSTALLATION
1) Install new intake manifold gaskets (1) to cylinder heads.
2) Install intake manifold (1).
Tighten bolts and nuts to specified torque.
Tightening torque
Intake manifold bolt and nut (a) :
23 N·m (2.3 kg-m, 16.5 lb-ft)
3) Install throttle body (2) to intake collector (1) with new throttle
body gasket.
Tighten bolts and nuts to specified torque.
Tightening torque
Throttle body bolt and nut (b) :
23 N·m (2.3 kg-m, 16.5 lb-ft)
4) Install EGR valve (1), EVAP canister purge valve (2), mani-
fold absolute pressure (MAP) sensor and each hoses to
intake collector and throttle body if removed.
Use new gasket, when installing IAC valve and EGR valve.
5) Install throttle body and intake collector assembly to intake
manifold with new intake collector gaskets.
1
(a)
(a)(a)
(a)
2 1
(b)
(b)
3. EVAP canister purge valve hose
2
1
3

6A2-10 ENGINE MECHANICAL (H27 ENGINE)
4) Disconnect EGR pipe from right (No.2) bank exhaust mani-
fold if right side exhaust manifold is removed.
5) Remove oil level gauge guide (3) if left side exhaust manifold
is removed.
6) Detach P/S pump assembly as following, if left side exhaust
manifold is removed.
a) Loosen P/S pump drive belt by loosening tensioner bolt.
b) Remove P/S pump mounting bolts.
c) Detach P/S pump assembly (4) with its hoses from cylinder
block.
7) Remove exhaust manifold covers (2) from exhaust manifolds
(1).
8) Hoist vehicle.
9) For 4WD vehicle, before disconnecting front propeller shaft,
put match mark (1) on joint flange and propeller shaft to facil-
itate their installation as shown in the figure.
10) For 4WD vehicle, disconnect propeller shaft from front differ-
ential.
11) Remove exhaust manifold stiffeners (1).
12) Remove stabilizer bar mounting bolt and pull down stabilizer
bar if right side exhaust manifold is removed.
13) Remove exhaust manifolds and their gaskets from cylinder
heads.
1
4
32
2. Exhaust No.1 pipe
A. Without WU-TWC
B. With WU-TWC

ENGINE MECHANICAL (H27 ENGINE) 6A2-11
INSTALLATION
1) Install new manifold gaskets to cylinder heads and No.1 pipe
gasket to exhaust No.1 pipe.
2) Install exhaust manifolds.
•Always install new bolts with pre-coated adhesive to the
locations with ✱ mark.
•Tighten both manifold nuts and bolts to specified torque.
Tightening torque
Exhaust manifold bolt and nut (a) :
30 N·m (3.0 kg-m, 21.5 lb-ft)
3) Install stabilizer bar if it was removed. Refer to “STABILIZER
BAR / BUSHINGS” in Section 3D.
4) Install exhaust manifold stiffeners (if removed).
5) Install exhaust No.1 pipe (1).
Tighten exhaust No.1 pipe bolts to specified torque.
Tightening torque
Exhaust No.1 pipe bolt (b) :
50 N·m (5.0 kg-m, 36.5 lb-ft)
6) Tighten exhaust No.1 pipe nuts to specified torque.
Tightening torque
Exhaust No.1 pipe nut (b) :
50 N·m (5.0 kg-m, 36-5 lb-ft)
1. Left (No.1) exhaust manifold
2. Right (No.2) exhaust manifold
2. Exhaust No. 2 pipe
1. Exhaust No.1 pipe
2. Exhaust manifold
A. Without WU-TWC
B. With WU-TWC

ENGINE MECHANICAL (H27 ENGINE) 6A2-15
INSPECTION
Cam wear
Using a micrometer, measure cam height. If measured height is
below its limit, replace camshaft.
Intake cam height :
Standard : 40.402 – 40.562 mm (1.5906 – 1.5969 in.)
Limit : 40.300 mm (1.3581 in.)
Exhaust cam height :
Standard : 39.428 – 39.588 mm (1.5523 – 1.586 in.)
Limit : 39.400 mm (1.5512 in.)
Camshaft runout
Set camshaft between two “V” blocks, and measure its runout by
using a dial gauge.
If measured runout exceeds below specified limit, replace cam-
shaft.
Camshaft runout limit :
0.04 mm (0.002 in.)
Camshaft journal wear
Check camshaft journals and camshaft housings for pitting,
scratches, wear or damage.
If any malcondition is found, replace camshaft or cylinder head
with housing. Never replace cylinder head without replacing hous-
ings.
Check clearance by using gaging plastic. The procedure is as fol-
lows.
1) Clean housings and camshaft journals.
2) Make sure that all valve lash adjusters are removed and
install camshaft to cylinder head.
3) Place a piece of gaging plastic the full width of journal of
camshaft (parallel to camshaft).
4) Install camshaft housing.
5) Tighten camshaft housing bolts in such order ([A] : “1” →
“17”, [B] : “1” → “19”) as shown in the figure a little at a time
till they are tightened to specified torque.
NOTE:
Do not rotate camshaft while gaging plastic is installed.
[A] : RH bank
[B] : LH bank

6A2-18 ENGINE MECHANICAL (H27 ENGINE)
INSPECTION
Valve guides
Using a micrometer and bore gauge, take diameter readings on
valve stems and guides to check stem-to-guide clearance. Be
sure to take reading at more than one place along the length of
each stem and guide.
If clearance exceeds limit, replace valve and valve guide.
Valve stem-to-guide clearance :
INSTALLATION
1) Clean mating surface on cylinder head and cylinder block.
Remove oil, old gasket and dust from mating surface.
2) Install knock pin (4) to cylinder block.
3) Apply sealant “A” to cylinder head gasket (1) as shown in the
figure.
“A” : Sealant 99000-31150
Sealant amount (Width “w”) :
4 mm (0.158 in.)
4) Install new cylinder head gasket (1) to cylinder block as
shown in the figure. carved lot number (5) on cylinder head
gasket (1) should face up (toward cylinder head side).Standard Limit
Valve stem
diameterIntake 5.965 – 5.980 mm
(0.2348 – 0.2354 in.)–
Exhaust 5.940 – 5.955 mm
(0.2339 – 0.2344 in.)–
Valve guide
I.D.In & Ex 5.985 – 6.010 mm
(0.2356 – 0.2366 in.)–
Stem-to-guide
clearanceIntake 0.035 – 0.045 mm)
(0.0014 – 0.0018 in.)0.07 mm
(0.0027 in.)
Exhaust 0.060 – 0.070 mm
(0.0024 – 0.0028 in.)0.09 mm
(0.0035 in.)
[A] : RH ( No.2) bank
[B] : LH (No.1) bank
2. Crankshaft pulley side
3. Flywheel side

ENGINE MECHANICAL (H27 ENGINE) 6A2-19
5) Install cylinder head to block.
After applying oil to cylinder head bolts, tighten them gradu-
ally as follows.
a) Tighten all bolts to 53 N·m (5.3 kg-m, 38.5 lb-ft) according
to numerical order in the figure.
b) In the same manner as in a), tighten them to 84 N·m (8.4
kg-m, 61.0 lb-ft).
c) Loosen all bolts until tightening torque is reduced to 0 in
reverse order of tightening.
d) In the same manner as in a), tighten them to 53 N·m (5.3
kg-m, 38.5 lb-ft).
e) In the same manner as in a) again, tighten them to speci-
fied torque.
Tightening torque
Cylinder head bolt (a) : 105 N·m (10.5 kg-m, 76.0 lb-ft)
Cylinder head bolt (hex hole bolt) (b) :
11 N·m (1.1 kg-m, 7.5 lb-ft)
6) Install water outlet cap.
7) Check timing mark on crankshaft as shown in the figure.
8) Install valve lash adjuster, camshaft, CMP sensor and RH
bank 2nd timing chain.
Refer to “CAMSHAFT AND VALVE LASH ADJUSTER” and
“RH (NO.2) BANK 2ND TIMING CHAIN AND CHAIN TEN-
SIONER” in this section. For CMP sensor, refer to “CMP
SENSOR” in Section 6F2.
9) Install 1st timing chain.
Refer to “1ST TIMING CHAIN AND CHAIN TENSIONER” in
this section.
10) Install LH bank 2nd timing chain.
Refer to “LH (NO.1) BANK 2ND TIMING CHAIN AND CHAIN
TENSIONER” in this section.
11) Install timing chain cover.
Refer to “TIMING CHAIN COVER” in this section. NOTE:
Don’t forget to install (b) bolts as shown in the figure.
1. Hex hole bolt
2. Crankshaft pulley side
3. Flywheel side
[A] RH bank
[B] LH bank
1. Crank timing pulley key
2. Oil jet