Engine Knocking While Reeving Engine Parked?

Engine has a knocking sound when I'm parked and rev the engine. Quiets down to nothing as its just running. But does knock for a second when I start the engine. I did an oil change and put some lucas in and it quieted it down a little but its still there. No metal was detected in the oil. I don't hear it when driving unless its just hard to hear. Any suggestions or tests I can do? Oil pressure seems fine. It does leak some oil over time. Someone said the engine might have a bad lifter vs spun rod. Or someone else listened sand said maybe its the exhaust. It sounds like its right in the middle of the driver seat and passenger. Back of the engine. It first started a while back after sitting for a while and it had lost some oil. Not realizing it I left my house and a couple houses down i noticed the oil pressure dropped so i turned around and switched vehicles. I did the oil change with the lucas as stated above and it has been driven. It seems to drive ok but it tends to knock and skip a bit when I gun it like its not getting enough power. Driving normal seems ok. Praying its not a spun bearing. I have had a few buddies take a listen and one said the engine was shot while 3 others said it either sounds like a lifter or maybe the exhaust or something else. Its not constantly knocking. Its an unusual case. A rattling type of knock

ford e-350 120,000k miles on it. Everything is in good shape other than the body and a speedometer needle going crazy. Tons of rust underneath. Thanks.

Added (1). Engine oil pressure seems ok. I put a new starter in today and right after i fired up the engine i didn't hear any knocking at all. But after shutting it off and running it another time it came back as it was before. Very strange. Engine 5.4L V8.

Chevy dodge or ford? Which to get? Also gas or diesel?

Gonna be using it to drive to work every day (30 minute drive) also my family startin our farm back up so gonna be pulling a trailer with 4 wheelers or couple cows in it for whenever go to auction barn or to pull a tractor trailer which would you get i know its up my choice and opinions but what would you pick

Added (1). ill be towing at the most 1 or 2 times a week

My 2000 Ford Windstar has a coolant leak. What could be causing it to leak?

It has two leaks. One is from the passenger side near the front tire and the second is right below the driver's seat. I have to replace the coolant after I have had the heater on for a bit. I never have it on for more than 15 min. Not because the coolant runs out in that time but I just don't use it for long.

I took it to the mechanic and he stated it was the "lower intake manifold gasket". I'm asking if anyone has any other ideas because that repair is pretty pricey.

Engine Knocking while parked accelerating?

Engine has a knocking sound when I'm parked and rev the engine. Quiets down to nothing as its just running. I did an oil change and put some lucas in and it quieted it down a bit but its still there. No metal was detected in the oil. I don't hear it when driving unless its just hard to hear. Any suggestions or tests I can do? Oil pressure seems fine. It does leak some oil over time. Someone said the engine might have a bad lifter vs spun rod. Or someone else listened sand said maybe its the exhaust. It sounds like its right in the middle of the driver seat and passenger. Back of the engine. Ford e-350 120,000k miles on it. Everything is in good shape other than the body and a speedometer needle going crazy. Tons of rust underneath. Thanks.

Added (1). Also has a hard time when i punch the gas while driving up hill.

How long are shocks good for?

I drive an 01 Ford Sport Trac that currently has 210k miles. I got the truck 4 years ago with about 120k miles on it. Within a year of having the vehicle the shocks were replaced. A couple of days ago I noticed the front drivers side was squeaking quite loud. I pulled the skirt from behind the tire and looked at the control arm bushings. (Upper) they seem to be worn out and I'm sure they're factory bushings. I've lubricated them but the squeaking persists. I'm beginning to wonder if it is the shock? How long are they good for and is there anything I can do to top it temporarily? I leave for basic training in January and I'm just trying to get by until I have the money to fix it myself.