I have never seen a locking oil cap. If you mean that it is loose or off, then you might get oil splatter all over your engine compartment. No big deal, as long as the oil level never got too low. Check the oil level, clean everything up and rest easy. No damage done.
The oil will squirt out
cap that covers the oil fill hole in engine
The engine oil could splash out of the oil fill hole.
it on top of the thermostat
Under the hood on the passenger side of engine compartment. Be sure the engine is cold when you remove the cap.
passenger side of engine compartment. just in front of shock tower.
in the top of the engine there is a cap with an oil can sign on it . Fill the oil in there. Be care not to over fill as it can cause the engine to cease!
Check the oil fill cap, it should require 5w20.Check the oil fill cap, it should require 5w20.
Let the engine cool and press down and twist the radiator cap to the left to remove it. Fill the radiator to the top and reinstall the cap. Check the coolant level in the overflow reservior and fill it to the fill line.
It is in behind the oil fill cap in the fill housing.
On a Lincoln LS : The engine coolant reservoir is located in the engine compartment , on the drivers side , near the firewall ( I believe it has a thread on cap , which would be the pressure cap / radiator cap )
The transmission fluid fill cap on a 1989 Chevy school bus with a diesel engine is under the air filter. The air filter has to be removed to see it.
Oil fill cap. If you cannot find the oil fill cap, you have no business doing your own repairs. Do not overfill or you may damage your engine.