When changing the engine oil on the 2023-2025 Corvette Z06 equipped with the 5.5L V8 engine (RPO LT6), it is critical to follow all steps in the Engine Oil and Oil Filter Element Replacement procedure in appropriate Service Information.

The 5.5L engine (RPO LT6) oil change procedure is different from the 6.2L engine (RPO LT2), which has just one drain plug.
The 5.5L engine has two oil drain plugs that must be removed during the oil change procedure.
There is a drain plug for the lower oil pan (Fig. 12, #3) and a drain plug at the oil tank location. (Fig. 12, #1)
Allow the oil to drain completely from both drain plug locations.

If one of the drain plugs is not removed during the oil change, allowing all oil to drain, adding new oil can overfill the engine, leading to potential drivability and/or engine damage concerns.

Checking the Oil Level

The high-performance engine lubrication system of the 5.5L engine operates differently than a standard engine lubrication system and requires a special procedure when checking the engine oil level. Follow this procedure closely.

The engine oil level must be checked when the engine is warm. A cold oil level in the dry sump tank may not indicate the actual amount of oil in the 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, which will reduce the amount of oil held in the dry sump tank.

In this case, there may not be any engine oil on the oil level indicator.
This is normal, since the oil level indicator is designed to read the engine oil level only after the engine has run long enough to reach normal operating temperature.

Do not add oil based on a cold engine oil level indicator reading.
The engine oil level on the oil level indicator must be checked while the engine is running at idle.

When changing engine oil and filter:

• Run the engine at idle for about 20 seconds to return all the oil back into the dry sump oil tank.
• Turn the engine off prior to draining the oil and remove the oil fill cap so the oil tank can breathe while it’s draining.
Drain the oil within 10 minutes of engine shutdown.
• Remove the drain plug from the bottom of the external engine oil tank, followed by removing the drain plug from the bottom of the engine crankcase (oil pan). Release the oil pan drain plug by pushing upward while turning 1/4 turn counterclockwise.
• Replace any damaged drain plug O-ring seals.
• Install the engine oil filter cap with a new engine oil filter cap seal ring and the new oil filter element.

Refer to Bulletin #24-NA-269 for more information.