Engine: Testing and Inspection
ADJUSTMENT1. INSPECT COOLANT
2. INSPECT ENGINE OIL
3. INSPECT BATTERY SPECIFIC GRAVITY
4. INSPECT AIR CLEANER FILTER ELEMENT SUB-ASSY
5. INSPECT FAN AND GENERATOR V BELT
HINT: Use of the automatic tensioner has made the tension and flexibility measurements unnecessary.
a. Check that the indicator mark on the automatic tensioner is within the A range as shown in the illustration.
b. When the mark is out of the standard range, exchange the V belt with new one.
6. INSPECT V-RIBBED BELT TENSIONER ASSY
7. WARM UP ENGINE
8. INSPECT IGNITION TIMING
a. When using LEXUS hand-held tester:
1. Connect a LEXUS hand-held tester to the DLC3.
2. Please refer to the LEXUS hand-held tester operator's manual for further details.
3. Start the engine at idle.
4. Using a timing light, check the ignition timing.
Ignition timing: 8 - 12° BTDC @ idle (Transmission in neutral position)
5. Disconnect the LEXUS hand-held tester from the DLC3.
b. When not using LEXUS handheld tester:
1. Using SST, connect tachometer probe to terminal TAC of the DLC3.
SST 09843-18030
2. Connect the tester probe of a timing light to the yellow lead wire of the ignition coil connector for No. 1 cylinder.
3. Using SST, connect terminals TC and CG of the DLC3.
SST 09843-18040
4. Using a timing light, check the ignition timing.
Ignition timing: 8 - 12° BTDC @ idle (Transmission in neutral position)
5. Remove the SST from the DLC3.
6. Disconnect the timing light from the engine.
7. Disconnect the tachometer from the DLC3.
9. INSPECT ENGINE IDLE SPEED
a. When using LEXUS hand-held tester:
1. Connect a LEXUS handheld tester to the DLC3.
2. Please refer to the LEXUS hand-held tester operator's manual for further details.
3. Race the engine at 2,500 rpm for approximately 90 seconds.
4. Check the idle speed.
Idle speed (w/ Cooling fan OFF): 750 ± 50 rpm
5. Disconnect the LEXUS handheld tester from the DLC3.
b. When not using LEXUS hand-held tester:
1. Using SST, connect tachometer probe to terminal TAC of the DLC3.
SST 09843-18030
2. Please refer to the LEXUS hand-held tester operator's manual for further details. Race the engine at 2,500 rpm for approximately 90 seconds.
4. Check the idle speed.
Idle speed (w/ Cooling fan OFF): 750 ± 50 rpm
5. Remove the SST from the DLC3.
6. Disconnect the tachometer from the DLC3.
10. INSPECT COMPRESSION
a. Remove the V-bank cover.
b. Remove the air cleaner inlet and intake air pipe.
c. Disconnect the throttle control motor connector.
d. Remove the oil level gauge guide.
e. Remove the 8 ignition coils.
f. Remove the 8 spark plugs.
g. Disconnect the 8 injector connectors.
h. Inspect the cylinder compression pressure.
1. Insert a compression gauge into the spark plug hole.
2. Fully open the throttle forcibly by hand.
3. While cranking the engine, measure the compression pressure.
HINT: Always use a fully charged battery to obtain engine speed of 250 rpm or more.
4. Repeat steps (1) through (3) for each cylinder.
NOTICE: This measurement must be done in as short a time as possible.
Compression pressure: 1,226 kPa (12.5 kgf/cm2, 178 psi) or more
Minimum pressure: 981 kPa (10.0 kgf/cm2, 142 psi)
Difference between each cylinder: 98 kPa (1.0 kgf/cm2, 14 psi) or less
5. If the cylinder compression in one or more cylinders is low, pour a small amount of engine oil into the cylinder through the spark plug hole and repeat steps (a) through (c) for cylinders with low compression.
- If adding oil helps the compression, it is likely that the piston rings and/or cylinder bore are worn or damaged.
- If pressure stays low, a valve may be sticking or seating is improper, or there may be leakage past the gasket.
i. Connect the 8 injector connectors.
j. Install the 8 spark plugs.
k. Install the 8 ignition coils.
l. Install the oil level gauge guide.
m. Connect the throttle control motor connector.
n. Install the air cleaner inlet and intake air pipe.
o. install the V-bank cover.
11. INSPECT CO/HC
HINT: This check is used only to determine whether or not the idle CO/HC complies with regulations.
a. Start engine.
b. Hold the engine at 2,500 rpm for approximately 180 seconds
c. Insert CO/HC meter testing probe at least 40 cm (1.3 ft) into tailpipe during idling.
d. Immediately check CO/HC concentration at idle and/or 2,500 rpm.
HINT:
- Complete the measuring within 3 minutes.
- When performing the 2 mode (2,500 rpm and idle) test, follow the measurement order prescribed by the applicable local regulations.
If the CO/HC concentration does not comply with regulations, troubleshoot in the order given.
1. Check the heated oxygen sensor operation.
2. See the table for possible causes, then inspect and correct the applicable causes if necessary.
12. DRIVING TEST