As to your question whether or not damage can occur on an overfill:
You can *conceivably" hydrolock the engine and cause damage, but truth-be-known... I haven't actually heard this happening. The overfill ...if minor...finds its way to the air intake system via a hose or tubing to the intake system, and can sometimes gum up the air meter.
Best to drain all out, and start over. Collect all the oil coming out into clean, 1 gallon, clear plastic milk jugs....once you're done you will "see" exactly what came out...and you'll have less chance of too much going back in. Good to get in this habit ( although optional) during routine oil changes too.
A search will reveal these things. Proper oil level is determined ONLY when :
- car is level,
- oil is up to temp of about 190 degF,
- and engine is idling around 800-900 rpm.
If the car was warmed up before the drain, expect 6-7 qts to come from the oil tank, and 3-4 qts from the engine block. If drained cold, the numbers will be close to reversed, since more drained back down into the engine case ( where there is NO dipstick... the stick measures the TANK level !).
If your car has a front fender mount oil cooler, the total system capacity will be close to 13 qts. Only 10 qts total will be part of the change-out...almost 3 qts always stays behind ( don't freak..it's normal). Add 8 qts...run the engine until up to temp...add more only if needed and slowly thereafter.
Also, the oil level gauge only works during this idling/at level ground period. You will see (again..don't freak) the level gauge dropping REAL LOW into the RED zone while you're driving. Normal, ...since the moment you speed up the engine to even 1200 rpm or so, you'll notice a drop in the measured level in the tank.
Good luck !!
- Wil
