AMSOIL Technical Service Bulletin

TSB: MO-2012-07-01
Date: 7/1/12
Product Description: All AMSOIL Synthetic Motor Oils
Subject: Service intervals for certain GM vehicles equipped with HFV6 engines

OBJECTIVE:

Communicate revised AMSOIL motor oil and filter change interval recommendations for the following GM vehicles equipped with HFV6 engines: 2009 model year Buick Enclave; 2009 Chevrolet Traverse; 2007-2009 model year Cadillac CTS, SRX STS; 2007 and 2009 model year GMC Acadia; 2007 and 2009 model year Saturn Outlook. The revised recommendations were initiated in response to the GM Bulletin on the subject.

ISSUES:

GM published Bulletin #10287C on April 13, 2012 identifying a problem with premature timing chain wear on certain 2007 and 2009 model year vehicles equipped with an HFV6 engine. According to GM, under certain driving conditions, and with extended oil change intervals, the timing chain could wear prematurely and cause the illumination of the “Service Engine Soon” light. To prevent this condition, GM has notified dealers and customers of the required corrective service to reprogram the engine control module, including the engine oil life monitor. In affected vehicles, the oil change interval is based on engine revolutions and engine temperature, not mileage.

TECHNICAL DISCUSSION:

This mechanical problem is not being linked to lubricant performance, and the only solution is to have the vehicle’s engine control module recalibrated by a GM dealer. According to the GM bulletin, timing chain wear can be affected by the age of the engine oil and driving conditions. As timing chains wear, engine and valve timing accuracy falters and engine performance suffers. To prevent excessive timing chain wear GM dealers are required to reprogram the vehicle’s engine oil life monitor, which shortens the previous OEM-recommended oil change interval.

RECOMMENDATION:

Follow the GM Service Bulletin recommendations by having the engine control module reprogrammed, and follow the bulletin requirements of changing oil more frequently. Continue use of AMSOIL synthetic lubricants as the best defense against premature timing chain wear. AMSOIL OE motor oil is a lower-cost solution for the more frequent drain intervals required by GM to overcome this timing chain issue.