03 e 350 cutaway
 

i have a 2003 e 350 with 77k on it.lately I noticed i have been adding 1 quart of oil a week and also when accelerating at around 40mph to 50mph it sound like a rattle can coming from the engine and it loses power.but normal driving seems to be fine.i hope i explained it the right way.

Gas or Diesel?

sorry gas

I would be checking the pcv valve to see if it is faulty first.

I'm a little curious about the rattle noise you mention.
Usually if the EGR system isn't working correctly ( staying closed) it could produce a pre ignition/ detonation sound , but would not necessarily cause a power loss.
A knock sensor could be responding to the rattle noise and reducing timing advance which might be felt as a loss of power. Sooo,
A thorough check of the EGR system would be a good place to start checking.
A carbon clogged EGR passage, a Faulty EGR valve itself, loss of vacuum control to the valve etc. If you find the solution, please share it with us. Thanks

Lets hope there isn't a more serious internal engine problem involving the unusual oil consumption

it is def a knocking sound when I accelerate aggressively.how about my fuel filter or a vacum leak? I have to bring it in soon just want to finf the right mechanic to look at it.

I really do not think a fuel filter or any type of vacuum leak would produce the knocking you describe. Usually when an engine knocks under load it involves a connecting rod bearing. We also don't overlook a loose flex plate connecting the flywheel to the torque converter. The problem is ; why the high oil consumption unless it's leaking where you can't see it. It is going to require a thorough check and there could be more than one thing wrong in there.

i actually for the first time put 94octane in today and there was no pinging or knocking at all.So i will stay with this for a while and see what happens.