If the oil level is too low, it can cause aeration, which is very differant to cavitation. Cavitatation can be caused by a blocked sustion filter/screen and is generally worse when cold and gets better as the oil heats up.....less resistance to oil flow...
But yes low oil and aeration will give problems........check for frothing of the oil. And being a Ford, and if its not sheded all the time, the oil will most likely be full of water too.

