I have a 2004 Expedition. I change oil every 3,000 mile's. For the past few week's my car has had a slight knock noise when I first start it so I took it to a oil change place today and the told me I had no oil at all on my dipstick. They said there is no way to tell if I had any engine damage. I had the oil changed at a different place December 22nd and about 2,000 miles back. I do not have a oil leak. Does this indicate the former oil change station didn't put enough oil in my car? I don't understand where the oil went since I don't have a leak.

 

How much oil did it take to bring it up to the full mark? Some of those engines took close to 7 quarts of oil, some took 5. So it is possible there was not enough oil put in the engine. I do not think there is any damage done to your engine. Filling it back to the full mark should alevieate the little noise you have on start up.