Oil checking TSB for LS7 2006-2008 05-06-01-032B

[c4c5specialist]

The engine oil level indicator handle is a yellow loop. The level indicator is located on the dry sump engine oil tank. The location of the dry sump engine oil tank is on the passenger side of the vehicle.

Z06 models have a dry sump engine lubrication system. This high-performance system operates differently than a standard engine lubrication system and requires a special procedure when checking the engine oil level. Follow this procedure closely when checking the engine oil level.

The engine oil level must be checked when the engine is warm. Cold oil level in the dry sump tank may not indicate the actual amount of oil in the system. With this system, engine oil is contained in an external tank, separate from the engine.

Under normal operating conditions, the oil pan under the engine does not store any oil. If the vehicle has been parked for an extended period without the engine being started, some oil will seep back into the oil pan, reducing the amount of oil held in the dry sump tank and there could be no engine oil at all showing on the level indicator.

This is normal since the level indicator is designed to read engine oil level only after the engine has run long enough to reach normal operating temperature. Do not add engine oil based on cold engine level indicator readings. The engine oil level on the level indicator will also be inaccurate if checked while the engine is running.

To obtain an accurate engine oil level reading, warm up the engine to at least 175°F (80°C). Cold oil will not give a correct oil level reading.
Once the engine is warm, turn off the engine. Checking the oil while the engine is running will result in an incorrect oil level reading.
Wait at least five minutes (but not more than 20 minutes) to allow oil to drain and settle in the engine.
Remove the level indicator from the external engine oil tank and clean it with a lint-free paper towel or a cloth. Re-insert the level indicator into the external oil tank, pushing it all the way in until it stops.
Remove the level indicator from the oil tank and read the level on the cross-hatched area. Oil levels that fall in the cross-hatched area are normal.

Being that oil level checking is different in a few manuals, this is the TSB released by GM Feb 28, 2008.
Allthebest, c4c5

[jub jub]

Thanks for posting paul!

[dsinned]

Yes, thanks C4C5(C6?)specialist. So, the important thing to remember is . . .

To obtain an accurate engine oil level reading, warm up the engine to at least 175°F (80°C). . . Once the engine is warm, turn off the engine. . . Wait at least five minutes (but not more than 20 minutes) to allow oil to drain and settle in the engine.

BTW, how do you drain the oil from the LS7 and/or reservior tank when it is due for a change?

[allanlaw]

Originally Posted by dsinned

BTW, how do you drain the oil from the LS7 and/or reservior tank when it is due for a change?

Two drain plugs in the oil pan down under the engine.