Do you need to check two possibilites, one, check if the oil is from transmission or from the engine, if the oil is red,is from transmission and you need to replace radiator, if the oil if from the engine you got it a big problem, because the only way that the engine oil is inside the radiator is because the engine has a bad head gasket, that mean you need to repair the engine heads.
3.8L or 4Quarts
Yes, there is an "O" ring inside the fittings.
The engine
Try to determine the substance: i.e. Transmission fluid (bad radiator) Engine oil (bad head gasket) Try flushing the cooling system and tracking other fluid levels
A 2004 Chevrolet Venture is tuned up by replacing the spark plugs, cleaning the fuel injector, and changing the oil. This will help improve performance and prolong its life.
4.5 quarts
On V6 models, the knock sensor is located on the front (radiator) side of the engine block above the oil filter.
5w30
5w-30w is best.
5w30
The oil drain valve on a 2000 Ford Explorer Sport is located near the rear of the oil pan. The radiator drain petcock is located at the bottom the radiator.
On a 2000 Chevrolet Venture, the oil drain plug is located on the bottom of the engine oil pan, which is situated beneath the vehicle. To access it, you typically need to raise the car using a jack and secure it with jack stands. The drain plug is usually a hex or square-shaped bolt, and you will need the appropriate socket or wrench to remove it for oil changes. Always ensure the vehicle is cool and secure before attempting to change the oil.