Engine - Oil Consumption/Driveability
NO.: 92-T-14BDATE: January, 1995
GROUP: Engine
CORP. NO.: 286101R
SUBJECT:
Oil Consumption on DOHC Engines or Carbon Buildup on SOHC Engines (Replace Valve Seals)
Due to new procedures, this bulletin supercedes bulletin 92-T-14A, which should be discarded.
AFFECTED MODELS:
All 1991 and 1992 Saturns built before, and including VIN NZ241997 with SOHC (LKO) engines and VIN NZ237282 with DOHC (LLO) engines.
CONDITION:
The DOHC engine may have higher than normal oil consumption (0.95L [1 qt.] or more in 3218 km [2000 miles]). The SOHC engine may have a stumble on deceleration or a misfiring cylinder while driving. Oil consumption may also be noticed on the SOHC engine.
CAUSE:
Valve stem seals may be worn, allowing oil to leak down the valve stem into the cylinder. On DOHC engines this condition will most likely lead to a comment of higher than normal oil consumption. On SOHC engines, this condition may cause carbon buildup within the cylinders, resulting in various driveability complaints such as miss or stumble.
CORRECTIVE ACTION:
On DOHC engines, perform an oil consumption verification test and replace all valve seals if required. On SOHC engines, verify operation of ignition and engine control systems, remove carbon from valves and cylinders and replace all valve seals.
IMPORTANT:
For further information on oil consumption, refer to "Technical Information Bulletin 94-T-59."
PROCEDURE:
DOHC/SOHC ENGINES WHEN THE CONCERN IS HIGHER THAN NORMAL OIL CONSUMPTION
^ Check for external oil leakage.
^ Check fresh air hose and PCV valve for higher than normal oil pullover.
^ Verify oil consumption by performing an oil consumption test as follows:
1. Change oil and oil filter (3.8 liters [4 quarts] of oil are required to properly fill the crankcase).
2. Start engine and bring up to normal operating temperature 97° - 100°C (197° - 212°F).
3. Park vehicle on level ground and wait a minimum of five minutes after engine is shut off. Check engine oil level, make sure it's at the FULL mark on the dipstick.
4. Mark dipstick with a scribe if not exactly at FULL mark.
5. Record the vehicle's mileage, date of oil change and exact location of oil level on the Customer Service Order.
6. Have the customer check the engine oil level at each fuel fill and return the vehicle if the oil level is at the "ADD" mark. If the oil level remains in the cross-hatch area, have the customer continue operating the vehicle for a minimum of 3218 km (2000 miles) before returning the vehicle for final oil consumption verification.
^ If the engine is using more than O.95L (1 qt.) per 3218 km (2000 miles), based on the oil consumption verification test, perform an engine cylinder compression test as outlined in the "Engine Mechanical Service Manual."
- If engine cylinder compression is found to be within acceptable limits, replace all valve stem seals.
- If engine cylinder compression is found NOT to be within acceptable limits, perform the required repairs according to information in the "Engine Mechanical Service Manual."
SOHC ENGINE: WHEN THE CONCERN IS STUMBLE ON DECELERATION OR A MISFIRING CYLINDER WHILE DRIVING
^ Verify that the ignition system and engine controls are operating correctly. Refer to the "Electronic Engine Controls Service Manual" for proper test procedures.
^ Using GM Top Engine Cleaner (or equivalent), remove carbon from the valves and cylinders per cleaner manufacturer's instructions.
^ Replace all valve seals.
VALVE SEAL REPLACEMENT O2
Valve seals can be replaced on both engines without removing the cylinder head or front cover. For service procedures, refer to the appropriate "Valve Spring and Stem Seal Replacement In-Vehicle" section (depending on engine type), in the "Engine Mechanical Service Manual."
NOTE:
On the DOHC engine, always remove the hydraulic lifters immediately after each camshaft is removed. Removing the lifters from the cylinder head immediately after camshaft removal prevents the lifters from being filled with oil or pumped up. If the lifters are not removed, the engine may have to sit for several hours after the camshafts are installed, allowing the lifters to bleed down.
Four service tools are required to replace the valve stem seals.
^ SA9127E, Universal Pressure Test Kit. Adapters from the kit are used to pressurize the combustion chamber and hold the valves closed when replacing the valve stem seals.
^ SA9122E, DOHC Camshaft Tool. This tool is used to hold camshafts in place on the DOHC engine when removing lifters, valve spring cap locks, valve springs and valve stem seals.
NOTICE:
Do not use aftermarket valve spring remover and installation tools as lifter bore and/or valve stem damage may occur.
^ 5A9124E, Universal Valve Step Spring Compressor. This tool is used to remove valve spring cap locks.
^ SA9102E, Valve Seal Removal Tool. This tool is used to remove and replace valve seals.
Once the valve stem seals are removed, inspect the valve stem for retainer lock damage to the valve stem during disassembly, scratches, scoring or scuffing. If the valve stem is damaged, the cylinder head will have to be removed and the valve replaced.
If the condition is acceptable, the valve guide and stem must be cleaned and lubricated with engine oil before installing a new valve seal.
NOTICE:
The valve seal's sealing lip is usually damaged by the valve stem lock grooves when removed. If a seal is removed for any reason, the seal must be discarded and a new one installed. The valve stem must be lubricated with clean engine oil prior to installing the valve seal. After the seal is installed, the valve stem and seal must again be lubricated with clean engine oil.
After the new valve seals are installed, change the engine oil and filter, warm-up the engine and check for oil leaks. Ask the customer to continue monitoring oil level, following the guidelines found in the "Maintenance Schedule" section labeled "Scheduled Maintenance Services" of tile "Owner's Handbook." The Owner's Handbook recommends the oil level be checked at each fuel fill.
PARTS REQUIREMENTS:
21000872 Filter Asm-Oil
21006516 Seal Asm-Valve Stem Oil, 8-SOHC, 16-DOHC
CLAIM INFORMATION:
To receive credit for this repair during the warranty coverage period, submit a claim through the Saturn Dealer System as shown.