Engine - MIL ON, Runs Rough, Misfire DTC's, Oil Consumption
L-SB-0125-12
November 30, 2012
MIL "ON" DTC P030#, Intermittently Runs Rough, and/or Engine Oil Consumption
Service Category
Engine/Hybrid System
Section
Engine Control
Market
USA
Applicability
Introduction
Some 2006 model year GS 300 vehicles may exhibit one or more of the following conditions:
^ MIL "ON" DTC P0300, P0301 P0302, P0303, P0304, P0305, and/or P0306.
^ Intermittently runs rough after coming to a stop with the engine at operating temperature.
^ Intermittently runs rough with engine misfires present after a cold soak startup.
^ Engine oil consumption exceeding 1 quart in 1,200 miles.
The piston ring set has been updated. Follow the procedures in this bulletin to address these conditions.
Warranty Information
Parts Information
Required Tools & Equipment
Repair Procedure Overview
1. Confirm the condition referring to the correct diagnostic procedure:
^ Refer to Diagnostic Procedure A for MIL "ON" P030# and/or Intermittently Runs Rough.
^ Refer to Diagnostic Procedure B for engine oil consumption.
2. Following duplication of the condition, proceed with engine removal and disassembly.
3. Replace all the piston rings with the updated parts.
4. DECARBONIZE THE CYLINDER HEADS, VALVES, PISTONS, AND CYLINDER BORES.
5. Replace the valve stem seals.
6. Replace the valve springs and valve lash adjuster assemblies ONLY if applicable (refer to Repair Procedure for more details).
Diagnostic Procedure A
1. Confirm that the condition is applicable per the Introduction.
2. Perform misfire diagnosis.
Refer to the Technical Information System (TIS) 2006 model year GS 300 Repair Manual: Engine/Hybrid System - Engine Control - "3GR-FSE Engine Control System: SFI System: P0300-P0306: Random / Multiple Cylinder Misfire Detected"
NOTE
^ Normal mechanical engine condition, engine control system, fuel supply/injection systems, and ignition system operation must be present or this bulletin does NOT apply.
^ Utilize the Techstream Snapshot function and Misfire Monitor information following startup and test drive to determine if a duplicated rough running condition coincides with misfire counts.
^ Multiple misfire counts for one or more cylinders must be recorded for this bulletin to apply. The misfire must be intermittent for this bulletin to apply.
3. If the concern is NOT resolved after following the Repair Manual misfire diagnosis proceed with the repair procedure below.
Diagnostic Procedure B
Perform an oil consumption test to determine the consumption rate.
1. Confirm the engine oil level is full.
2. Mark the oil dipstick to indicate the current level.
3. Replace the oil dipstick.
4. Mark the oil dipstick oil drain plug and oil fill cap to prevent/indicate tampering during the test.
HINT
Use tape, sealer; cable ties, or equivalent to mark the oil dipstick, oil drain plug, and oil fill cap.
5. Advise the customer to drive the vehicle normally for 1,200 miles and return for inspection.
6. Determine the quantity of oil that was consumed in 1,200 miles.
Was the oil level more than 1 quart low after 1,200 miles of normal driving?
^ YES - Go to the Repair Procedure.
^ NO - This bulletin does NOT apply. Warranty guideline for acceptable oil consumption is 1 quart per 1,200 miles of operation. No warranty claim should be filed.
Repair Procedure
1. Prior to disassembly confirm NO abnormal engine knock noises are present.
HINT
If no abnormal engine knock is detected, all bearings and bushings should be OK to reuse.
2. Remove the engine assembly.
Refer to TIS 2006 GS 300 Repair Manual:
Engine/Hybrid System - Engine Mechanical - "3GR-FSE Engine Mechanical: Engine Assembly Removal"
3. Disassemble the engine to replace the piston rings.
HINT
Only disassemble what is necessary for the parts being replaced.
Refer to TIS 2006 GS 300 Repair Manual:
Engine/Hybrid System - Engine Mechanical - "3GR-FSE Engine Mechanical: Engine Unit: Disassembly"
4. Inspect and CLEAN THE ENGINE COMPONENTS RELATED TO THIS REPAIR.
Refer to TIS 2006 GS 300 Repair Manual:
Engine/Hybrid System - Engine Mechanical - 3GR-FSE Engine Mechanical: Engine Unit: Inspection"
A. THOROUGHLY CLEAN AND DECARBONIZE THE CYLINDER HEAD AND VALVES.
B. THOROUGHLY CLEAN AND DECARBONIZE THE PISTONS AND ENGINE BLOCK CYLINDER BORES.
NOTE
Engine block components (i.e., piston pin bushing, connecting rod bearings, etc.) found to be outside of Repair Manual specification as per the Inspection Procedure should be replaced as necessary.
HINT
If necessary, sublet specialized and precision operations to a local engine machining shop.
C. Inspect the cylinder bore for abnormal damage.
Visually check the cylinder bore for the presence of crosshatch.
^ If the cylinder bore has visible crosshatch the cylinder block is OK to re-use.
^ Confirm that only light vertical marks are present if any.
NOTE
^ It is normal for an in-service block to have light markings present from carbon and should not be interpreted as excessive cylinder wall scratches.
^ ONLY replace the short block if multiple, severe scratches are present.
^ Do NOT hone the cylinder walls.
D. Following engine component inspection note the part numbers required for the repair.
5. Reassemble the engine with the following new parts:
^ Piston ring set
^ Valve stem seals
^ Valve springs valve, spring retainers, and valve lash adjusters if necessary (see Note)
^ Replace any other components as necessary ONLY if measured out of specification during inspection.
For reassembly instructions refer to TIS 2006 GS 300 Repair Manual:
Engine/Hybrid System - Engine Mechanical - "3GR-FSE Engine Mechanical: Engine Unit: Reassembly"
6. Reinstall the engine assembly.
Refer to TIS 2006 GS 300 Repair Manual:
Engine/Hybrid System - Engine Mechanical - "3GR-FSE Engine Mechanical: Engine Assembly: Installation"
7. Verify normal vehicle operation.
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