DJayAce

I have a 2004 Ford F150 5.4 V8 with 191k miles. Last oil change was done 5k miles ago. Truck takes 7 Quarts of oil. I always use Full Synthetic Mobil 1 with a Motorcraft filter. When I finished my oil change, I started poring the old oil into a 5 quart container, and the old oil only filled up 3/5 the way up, that's it.... I don't have any oil leaks, never had an oil drop on the ground ever. I'm 100% sure I put 7 quarts in it last go around, checked oil level and everything. Everything was done right, 100% sure of it. Where did 4 quarts go!?!?! That's quite the large amount to go missing.

I know I drained all the oil (mostly all ofc). When I put the new oil in, all oil levels check out perfectly fine for this go around after putting 7 quarts in. The level is perfectly in the middle of the gauge. So all is good there. Is there something common that can cause this that I need to maybe look into and troubleshoot?

needsmoarturbo

I have several vehicles with around our place of varying miles and use synthetic oil in all of them.
Seems like most of them use a QT or 2 between oil changes. I don't know where it goes I think it just blowby or vapors get sucked into the pcv system and burned up.
Id just advise to check the oil every other time you fill up the gas tank and top it off accordingly. Not sure that is a major concern for an engine with 200k miles.
You could try a different oil for giggles. I think in one of my previous cars it seemed like mobil 1 disappeared faster than some of the others I tried.

DJayAce

Yeah I might play around with it. Good idea checking it at fill ups. I'll do that. I don't have the greatest of memories but I think last time I did an oil change, I filled up a 5 quart container like 4/5 the way. This time 3/5. Idk it's crazy to it burn off 57% of it's oil in 5k miles. I read it could be bad valve stem seals. My exhaust never spits out smoke, not even the smallest visible amount at all, so idk. I'd love to tackle a seal replacement, there's just no videos on it for that engine. I read it's not good to ignore it though. I might start with the valve seals and go from there.

needsmoarturbo

I'll say it again. I really think the mobil 1 just seems to evaporate.
i would just check it more regularly and top it off every 1000 miles. I think if you search you will find it's not uncommon to have to add 1 quart per 1000 miles to a 5.4 running synthetic. If it's not puffing blue smoke or dripping on the ground I'd not worry too much. Adding $20 worth of oil in between oil changes is small potatoes in the big scheme.

D_cahala

I just changed to Mobil 1, so i WILL keep an eye on that too.

DJayAce

Back when I had my 2012 Cadillac CTS Coupe, owners manual said Full Synthetic Mobil 1. I do definitely remember never having the same amount that I put in, by a good quart or so, I vaguely remember. But yeah a 20 year old 5.4 Triton is a bit different situation. You're right, prob nothing to stress over, it just really surprised me to see it that low. Next oil change I'll see if I can get my hands on Motorcraft 5W20 full synthetic, but idk if it's even out there, at least not in any stores as far as I know. But that'll be a fun little test. I'll have to revisit this thread and post an update when that time comes.

Promodmerc

The filter holds a quart and all of the oil does not drain out.

bajaman

When I had my 5.4 3V Triton, I would get pretty much the full 7 quarts in recovery...I'd pour 5 quarts back into the jug to take to O'Reilly's for recycling, and then have 1.5 - 2 quarts for weed control on the fencelines of the ranch. NOTHING better for this than used oil mixed with oil well brine!