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Tech Notes


Engine Builders: Because some automakers have extended the length of oil drain intervals in their new vehicles it is important to understand how to determine the correct oil change interval.

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Looking in a vehicle owner’s manual will provide you with the oil drain interval that is prescribed by the engine manufacturer. Oil drain interval is determined by the engine type, drive train, vehicle type and expected use. Each OEM tests its own vehicles to determine the proper drain interval.

Some OEM’s may have changed to longer drain recommendations as engines and motor oils are far more advanced over those produced even a few years ago. This is not always true, so you should check the owner’s manual for the specific drain interval for every vehicle.


Understanding the type of driving a customer does with their vehicle is also beneficial. Generally speaking, most consumers drive a severe cycle of short trip or stop-and-go type travel, and using the severe service drain interval is recommended. With summer typically leading to increased travel, people who use their car, SUV or light duty truck for towing should also follow recommendations for severe service.

There is not a downside to more frequent oil changes. A shorter drain will provide the best defense against harmful engine deposits, better oil consumption control, improved fuel economy and lower wear on engine parts. More frequent oil changes may also help you discover a more serious engine problem such as a coolant leak before serious damage occurs.


Engine deposits and wear are slow, sure killers of performance and engine life. In most cases, by the time you are aware of an issue, the damage has been done and often cannot be reversed without an engine rebuild.

Changing the oil in a vehicle at the appropriate drain interval is the easiest, most cost effective insurance against lubricant related engine damage.

–Provided by Pennzoil

Figure 1 Some owners of Toyota/Lexus 3.5L engines may complain of oil leaks. Certain engines may have been built with insufficient gasket sealing in the area indicated by the arrow.

Engine Builders: The AERA Technical Committee offers the following information regarding an engine oil leak on 2005-2007 Toyota and Lexus 3.5L 2GRFE engines. Some vehicle owners may complain of oil leaks toward the front of these engines.


Certain 3.5L engines may have been manufactured with insufficient gasket sealing in area indicated by the arrow in Figure 1. Chart 1 also spells out which models, plants and VIN numbers are affected.

Chart 1

After confirming the leak in the suspect area, it will be necessary to remove the front cover and reseal the mounting areas using a FIPG (form in place gasket – Toyota p/n 08826-00080 or equivalent) sealant and Three Bond 1324 or equivalent. It is important to note that the Toyota FIPG requires assembly within three minutes of application to the surface.


Engine Builders: The AERA Technical Committee offers the following information regarding an engine noise on 2001-2002 Mitsubishi 3.5L VIN R engines. This noise is associated with the piston and may affect more than one cylinder at a time. Some have described the noise as a “dieseling” sound.

Some vehicles may experience a dieseling-type noise when the engine is idling. This may be due to the piston pins contacting the cylinder wall(s). To determine if this is the situation, inspect the cylinder walls for evidence of scuffing. If scuffing is observed, a boring repair is required. If scuffing is not noted, parts replacement may be required to eliminate engine noise.


To reduce the likelihood of this type of noise reoccurring, Mitsubishi offers a number of revised piston and pin assemblies – see Chart 2 for the specifics.

Chart 2

Description Bore Size Part Number
Piston & Pin Assembly A MD371361
Piston & Pin Assembly B MD371362
Piston & Pin Assembly C MD371363
Piston & Pin Assembly .5 mm Oversize MD371364
Piston & Pin Assembly 1.0 mm Oversize MD371365

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