Engine - Engine Oil System Flush
NUMBER: 02-110-10RDATE: 05-31-11
APPLICABILITY: All Turbo Models
SUBJECT: SUBARU GENUINE ENGINE OIL SYSTEM FLUSH
INTRODUCTION
The purpose of this bulletin is to announce a new product that is now available through the Subaru Genuine Chemical Program, "Subaru Engine Oil System Flush".
The main cause of turbocharger failure is lack of lubrication due to insufficient maintenance. Currently, 2010MY and prior turbocharged engines require that the oil and filter be changed every 3,750 miles (6,000km) or 3-3/4 months. All 2011MY turbocharged engines require that the oil and filter be changed every 7,500 miles (12,000 km) or 7.5 months.
Proper oil change maintenance is critical to the lubrication of engine components, especially in turbocharged engines. When engine oil maintenance is not performed at required intervals, oil gelling (sludge) and deposits caused by deterioration of the oil will clog oil passages, causing excessive wear from lack of lubrication. if the mesh filter screen located inside the banjo bolt that secures the turbocharger oil supply pipe to the back of the right cylinder head becomes clogged, the turbocharger will fail. In addition, this will also cause damage to the Active Valve Control System (AVCS). As a reference, refer to Service Bulletin 02-106-08R, Turbocharger Mesh Filter Screen.
Synthetic Oil
Subaru of America inc. recommends using synthetic motor oil in all turbo charged engines. When using synthetic oil, you must use oil of the same classification, viscosity and grade shown in this Owner's Manual, and must follow the oil and filter changing intervals shown in the maintenance schedule.
PART INFORMATION
EXAMPLES Of FAILED TURBOCHARGERS
Inadequate lubrication supplied to the turbocharger will cause damage to the turbine center shaft bearing. This will cause radial movement of the shaft permitting the compressor impellers to come in contact with the housing.
In this example, resulting from lack of lubrication, the turbine shaft broke causing the turbine to shift off center, making it non-functional.
Before replacing a damaged turbocharger, review the customer's maintenance history. If there is evidence that the engine was not properly maintained, follow the Engine Oil System Flush instructions prior to replacing the turbocharger to avoid a secondary failure.
Engine Oil System flush Instructions
1) Make sure the engine oil level is "FULL".
2) Start the engine and bring to operating temperature.
3) Turn the engine OFF.
4) Add Engine Oil System Flush to the engine oil.
5) Start the engine and let idle for 20 minutes.
6) Turn the engine OFF and drain the old engine oil and Engine Oil System Flush from the oil pan.
7) Replace the engine oil filter with a Genuine Subaru Oil Filter.
8) Refill the engine oil with the proper engine oil as recommended in the vehicle's owner manual.
Note:
Remember to always replace the banjo bolt and mesh filter screen when replacing the turbocharger. Anytime the banjo bolt is removed or replaced, both copper washers must be replaced with new ones. Proper vehicle maintenance should be reviewed with the customer to avoid a recurring problem in the future.