Soooo.....I bought a 2003 f-150 heritage with the 5.4 with 79,000 miles on it last August. Haven't put but 11,000 miles on it till now. Changed the oil in early June. Previous change had been mid January. 4,100 miles between changes. I was 2 1/2 quarts low. I have no leaks and visually or by smell don't appear to burn any. And no, I don't have any mixing in the antifreeze. What the hell?!?! Anybody?

 

Watch out for that haha threw me for a loop to right off the start these trucks burn oil idk about 2.5 quarts but I was a quart low my first oil change I had to ask a buddy that works at ford where it went he said they all do it when they hit about 100k he said there's nothing simple you can do to fix it unless you wanna re build so just keep a quart handy and at about 1800-2000 miles check the dipstick I go 3500 miles in between LOF changes so that may be why you burned more than I usually do

 

1st at the last change are you sure it was refilled to the full mark? have you been checking the oil on a reguler bassis and if so has it been going down slowly over time or all at once? if its been going down slowly you should never let it get 2 1/2 qts low. Oil does not evaperate so if its not leaking then its going out the tail pipe. Rings or valve seals suspect. I sugest you check it once a week and you will get a better idea if its actualy useing oil or it just wasnt full to start.

 

replace pvc than go from there

 

Yeah, I can say I've never had a vehicle where I had to check my oil so often. I appreciate your guys thoughts. I've set reminders to check it every 3 weeks and already have an extra quart handy. Btw, do you guys thinks its weird that there is no amber check oil light on that truck? I thought for sure it had one and that The dash Bulb was just burned out. That was until I checked the manual. I'm not making excuses here. I had a 94 ranger before this. 9 years older and it had an oil check light. Just sayin.

 

Well my 5.4 don't use any oil believe it are not. It it was pulled out of a high mileage truck and put in mine. I change it every 3,000 miles and it's always on the full mark an I never add any oil between oil changes

 

Mine has the same problem. Always thought it was strange to consume ~2qts between changes and have no leaks or burn it.. as in no blue smoke.

 

Could the catalytic converter some how be nutralizing or changing the chemical makeup of the exhaust so as not to notice the burn off?