Lost Oil/Pressure New F150 4.2
 

When performing oil change at 1st 3,000 mi. new oil filter was double casketed when old filter casket was left behind. Truck was driven 6.5 mi. before warning lite was noticed at which time engine was immediately cut-off. Remaining oil volume in crankcase was less than 1 qt. Seems to sound and run the same, can tell no difference. My question is at what volume of oil in crankcase is pressure lost? Also, even with loss of pressure, will the remaining oil in the system protect the internal parts for a "brief" time?

I couldn't give you an exact number, but your truck should be fine if there was a 6.5 mile drive and 1 qt was still in there. Yes, it will protect your engine briefly. If any amount of oil is in there, there is always about that much protection going on. I think you'll be fine...just watch for those double gaskets...they're a pain. Also, I would suggest lubing the gasket on the new filter before putting it on to prevent it from happening again. :-X22

Lost Oil/Pressure New F150 4.2
 

Thanks for your reply. Changed oil today after 500 miles since incident. Had very little but visible amount of small metal flakes in the bottom of drain pan. Your answer & this evidence has convinced me that it survived this in good shape. In my 30 years of changing my own oil I've never encountered a filter gasket separation. That day I was in a bit of a rush as it had started to rain in the middle of it all...As you can imagine I was very much upset by the whole thing..I've decided to switch to Valvoline 5W 30 at this time as I've basically voided my warranty on the engine anyway..(had it towed to dealer). I'm not convinced that the 20W is sufficient protection. Thanks again for your help, Howard

My guess is it will be OK.
About 15 years back, an friend of mine left the oil fill cap off after doing an oil change (Mitsubishi pick-up).
While driving down the Interstate, the engine started to knock, bang and then quit running. He found the oil not touching the dipstick. The engine appeared to be siezed.
After letting it cool down, he added several qts of oil to get the level up to normal. The engine started and ran fine.
The truck was traded about 50-60,000 miles later, but was still running fine.

Lost Oil/Pressure New F150 4.2
 

Brian, Just a final note; The procedure performed at the dealer may have helped slightly to lessen the harm done. After engine had cooled overnight, they drained remaining oil & removed filter. (actual amount was only 24 oz. + filter amount), added 6 qts with new filter. Disconnected ignition and cranked the motor in two 20 second intervals to "pump it up". Reconnected ignition then started. Brief Lifter noise for 2 or 3 seconds then quieted. Leaving on a road trip from Texas to Washington D.C. & down to FL. in a few weeks. I suppose this will be the "shake-down" run & if there is a problem I'll find out then..Thanks for your response, no need to reply-Howard