A friend of mine has a 99 F-150 with a v6 and wanted me to ask if anyone has heard of or had a problem of oil not showing up on the dip stick. He does not burn any that he's seeing, and does not leak any. He's the original owner with 24k on the truck. Any suggestions or answers let me see em. Thanks in advance. I told him it could be the wrong dipstick possibly that an oil change place or something could have put the wrong one in or something.

those engines naturally burn oil, more then most. partly design and partly the thin 5-20 oil they use. the newer ford engines all do that (4.2,4.6,5.4,5.8) i see them coming in for past due oil changes, knocking like crazy because they only have 3-4 quarts left in them. it is vital to change the oil every 3k because of this. if your friend does this(and not just say he does it) then it will only use about 1 to 1-1/2 quarts between changes.
on the other hand, the 4.2 is well known for its incredibly short life span. maybe he does have a problem? does it run poor?

The only thing that he has done to it as far as repairs go is the o2 sensor/s
When he has changed the oil in the past he has measured and gotten the same amount of oil out of the vehicle from what he says. With him running the 5/20 should he add lucas synthetic additive will that help him at all?

he can try it, see if it helps. a friend of mine put that stuff in his grandmothers old crown vic (early 4.6)along with a little thicker oil to try and get it through emissions. It worked, after several past attempts it flew right through with that mixture. but then he drained it back out and put 5-30 in it.

i would personally try changing to 10-30 first. if that doesn't help enough then go ahead and add a bottle lucas oil.

Also have him check the tube that holds the dip stick. Mine just rusted through so the dip stick just stuck through to open air. I am going to have to pull the oil pan to get the old one out. :crying:

those engines naturally burn oil, more then most. partly design and partly the thin 5-20 oil they use. the newer ford engines all do that (4.2,4.6,5.4,5.8) i see them coming in for past due oil changes, knocking like crazy because they only have 3-4 quarts left in them. it is vital to change the oil every 3k because of this. if your friend does this(and not just say he does it) then it will only use about 1 to 1-1/2 quarts between changes.
on the other hand, the 4.2 is well known for its incredibly short life span. maybe he does have a problem? does it run poor?

My 4.2 is still going at 142K miles and doesn't burn any oil.

thats pretty low milage, but on my 01 i had the same problem, changed the pcv valve and havent used a drop since. for 8 bucks give it a try, remember to use motorcraft.