G16E-GTS (ENGINE MECHANICAL): ENGINE: ON-VEHICLE INSPECTION; 2023 - 2025 MY GR Corolla [09/2022

Last Modified: 05-13-2024	6.11:8.1.0	Doc ID: RM10000000260T4
Model Year Start: 2023	Model: GR Corolla	Prod Date Range: [09/2022 - ]
Title: G16E-GTS (ENGINE MECHANICAL): ENGINE: ON-VEHICLE INSPECTION; 2023 - 2025 MY GR Corolla [09/2022 - ]

ON-VEHICLE INSPECTION

CAUTION / NOTICE / HINT

CAUTION:

When working near the engine room while the engine has started or the power source mode is engine switch on (IG), do not touch the fan and generator V belt or rotating components such as the fan, etc.
Touching the fan and generator V belt or rotating components such as the fan, etc. could result in your hand or clothing getting caught and pulled in.

PROCEDURE

1. INSPECT ENGINE COOLANT

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2. INSPECT ENGINE OIL

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3. INSPECT AUXILIARY BATTERY CONDITION

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4. INSPECT SPARK PLUG

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5. INSPECT AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY

(a) Remove the air cleaner filter element sub-assembly.

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(b) Visually check that the air cleaner filter element sub-assembly is not damaged or excessively oily. If necessary, replace the air cleaner filter element sub-assembly.

HINT:

If there is any dirt or clogs in the air cleaner filter element sub-assembly, clean it with compressed air.
If any dirt or clogs remain even after cleaning the air cleaner filter element sub-assembly with compressed air, replace it.

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6. INSPECT FAN AND GENERATOR V BELT

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7. INSPECT V-RIBBED BELT TENSIONER ASSEMBLY

(a) Remove the fan and generator V belt.

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(b) Turn the V-ribbed belt tensioner assembly clockwise and counterclockwise and check that it turns smoothly and does not catch.

HINT:

If the V-ribbed belt tensioner assembly does not turn smoothly or catches, replace the V-ribbed belt tensioner assembly.

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8. INSPECT VALVE LASH ADJUSTER ASSEMBLY NOISE

(a) Rev up the engine several times. Check that the engine does not emit unusual noises.

(b) If unusual noises occur, warm up the engine and idle it for 30 minutes or more, then perform the inspection.

HINT:

If any defects or problems are found during the inspection, perform the valve lash adjuster assembly inspection.

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9. INSPECT IGNITION TIMING

NOTICE:

Check the ignition timing with the cooling fan off.
Turn off all electrical systems and the A/C.
When checking the ignition timing, the transaxle should be in neutral or park.

(a) Warm up and stop the engine.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Enter the following menus: Powertrain / Engine / Data List / Ignition Timing Cylinder #1.

Powertrain > Engine > Data List

Tester Display
Ignition Timing Cylinder #1

Standard Ignition Timing:

Condition	Specified Condition
Idle speed	-5 to 15°CA BTDC

(f) Enter the following menus: Powertrain / Engine / Active Test / Activate the TC Terminal / ON.

Powertrain > Engine > Active Test

Active Test Display
Activate the TC Terminal

Data List Display
Ignition Timing Cylinder #1

(g) Monitor Ignition Timing Cylinder #1 of the Data List.

Standard Ignition Timing:

Condition	Specified Condition
Idle speed	8 to 12°CA BTDC

(h) Enter the following menus: Powertrain / Engine / Active Test / Activate the TC Terminal / OFF.

(i) Check that the ignition timing advances immediately when the engine speed is increased.

10. INSPECT ENGINE IDLE SPEED

NOTICE:

Check the engine idle speed with the cooling fan off.
Turn off all electrical systems and the A/C.
When checking the engine idle speed, the transaxle should be in neutral.

(a) Warm up and stop the engine.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Enter the following menus: Powertrain / Engine / Data List / Engine Speed.

Powertrain > Engine > Data List

Tester Display
Engine Speed

(f) Read the value displayed on the tester.

Standard Idle Speed:

Condition	Specified Condition
N Position	950 to 1050 rpm

11. INSPECT COMPRESSION

NOTICE:

Keep the spark plug holes free of foreign matter when measuring the compression pressure.

(a) Warm up and stop the engine.

(b) Check for DTCs.

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(d) Disconnect the No. 5 engine wire connector.

(e) Disconnect the No. 6 engine wire connector.

(f) Check the cylinder compression pressure.

(1) Insert a compression gauge into the spark plug hole.

(2) Fully open the throttle.

(3) While cranking the engine, measure the compression pressure.

Standard Compression Pressure:

Item	Minimum Compression Pressure	Standard Compression Pressure
No.1 Cylinder	980 kPa 10.0 kgf/cm² 142 psi	1300 kPa 13.3 kgf/cm² 189 psi
No.2 Cylinder	980 kPa 10.0 kgf/cm² 142 psi	1300 kPa 13.3 kgf/cm² 189 psi
No.3 Cylinder	980 kPa 10.0 kgf/cm² 142 psi	1300 kPa 13.3 kgf/cm² 189 psi
Pressure Difference between Each Cylinder	-	200 kPa or less 2.0 kgf/cm² or less 29 psi or less

NOTICE:

Always use a fully charged auxiliary battery to obtain an engine speed of 250 rpm or more.
Inspect all cylinders in the same way.
Measure the compression pressure as quickly as possible.

(4) If the cylinder compression pressure is low, pour a small amount of engine oil into the cylinder through the spark plug hole and inspect it again.

HINT:

If adding engine oil increases the compression pressure, the piston rings and/or cylinder bore may be worn or damaged.
If the compression pressure stays low, a valve may be stuck or seated improperly, or there may be leaks in the cylinder head gasket.

(g) Connect the No. 6 engine wire connector.

(h) Connect the No. 5 engine wire connector.

(i) Install the 3 spark plugs.

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(j) Clear the DTCs.

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NOTICE:

After the inspection, clear the DTCs, check for DTCs again and make sure the normal system code is output.

12. INSPECT CO/HC

HINT:

This check determines whether or not the idle CO/HC complies with regulations.

(a) Start the engine.

(b) Run the engine at 2500 rpm for approximately 180 seconds.

(d) Immediately check the CO/HC concentration during idle and when the engine is running at 2500 rpm.

HINT:

When performing a 2 mode (with the engine idling/running at 2500 rpm) test, the measurement procedures are determined by applicable local regulations.

If the CO/HC concentration does not comply with the regulations, perform troubleshooting in the order given below.

(1) Check for DTCs.

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(2) See the following table for possible causes, then inspect the applicable parts and repair them if necessary.

CO	HC	Problem	Cause
Normal	High	Rough idle	Faulty ignition: Incorrect valve timing Fouled, shorted or improperly gapped spark plugs Incorrect valve clearance (valve lash adjuster assembly) Leaks in intake or exhaust valves Leaks in cylinders
Low	High	Rough idle (Fluctuating HC reading)	Vacuum leaks: PCV hoses Intake manifold Throttle body with motor assembly Lean mixture causing misfire
High	High	Rough idle (Black smoke from exhaust)	Restricted air cleaner filter element sub-assembly Plugged PCV valve Faulty SFI systems: Fuel pressure regulator assembly Engine coolant temperature sensor Mass air flow meter ECM Fuel injector assemblies Throttle position sensor (built into throttle body with motor assembly)