Engine Builders: Why is synthetic motor oil superior to conventional motor oil? Full synthetic motor oils outperform conventional and synthetic blend motor oils in nearly all aspects of engine protection. Full synthetics start with a quality base oil combined with an additive formula that enables it to help provide superior protection to prevent friction, resist burn-off, oxidation, shear and sludge. This additive formula includes detergents, anti-wear agents, friction modifiers, dispersants, viscosity index improvers, and antioxidants to help the engine run better.
Synthetic motor oil is manufactured with a process that makes it possible to manipulate the oil molecules. Oil molecules come in all shapes and sizes. In synthetic oil, the molecules are broken down and rebuilt to exact shapes and sizes to better resist chemical attack and oxidation.
At high temperatures, oil can also burn off, depleting the oil level and leaving behind thicker oil that drags on performance. Full synthetic motor oil resists burn-off much better than conventional motor oils.
Full synthetic motor oil also resists oil oxidation better than conventional oil. Oil oxidation occurs when oil molecules bond together, which can lead to deposits that can cause reduced performance. Full synthetic motor oils help to prevent engine deposits; that result in smoother oil flow and cleaner engine operation.
As motor oil travels through the engine, some of the additives can be sheared, literally cut in half, by high-speed engine parts, thinning the oil. Full synthetic motor oils resist shear under heavy loads better than conventional oils. This helps synthetic motor oil maintain its viscosity grade, enabling it to offer better engine protection and withstand more extreme engine conditions.
Finally, sludge can form during low-temperature driving when water and fuel condense and mix with motor oil. This sticky mixture may block oil flow through the oil pump, oil passages and oil filter. Full synthetic motor oil is formulated to provide an extra level of sludge resistance, breaking-up sludge-forming particles.
Engine Builders: The AERA Technical Committee offers the following information regarding revised valve springs for 2004-2005 GM 3.5L VIN 6 engines. Some customers may comment on an occasional check engine light flashing. Additionally, some customers may comment on a light engine knocking or mis-fire noise during warm up or on a deceleration after the engine is fully warmed.
Upon investigation, the technician will find a misfire code P0300 through P0305 if the condition persists long enough. To determine the cause of the above codes perform the diagnosis for the P0300 code as found in the appropriate section of the service information. If no concern is isolated through the diagnosis tree, then replace all of the exhaust valve springs and seals.
Figure 1 is a complete list of the revised parts required to make a successful repair. Aftermarket parts are currently unavailable for this revised valve spring.
Engine Builders: The AERA Technical Committee offers the following information regarding a revised camshaft sprocket bolt torque specification for 1.8L Volkswagen/Audi 1.8L AEB engines.
Previously published service information may have incorrectly listed a torque of 74 ft.lbs.
The correct torque value for the camshaft sprocket bolt is 48 ft.lbs. (65 Nm). See
Figure 2
for illustrations of the valve train component.
Some of these engines’ cylinder heads are currently frequenting machine shops as many miles have accumulated since they were new. The value of the previously listed torque, if used, may later create an engine failure if the bolt does not break while torquing. If it only over-stresses while assembling and the bolt breaks while the engine is running, it is possible all engine valves (20) will bend or break.
