hctub

My stepdad has a 1997 F150 with the 5.4 engine. After driving 150 miles it now uses 1.5 quarts of oil so about a quart for every 100 miles. It doesn't smoke and doesn't leak so I can't figure what it can be.

Any thoughts will be appreciated.

Monkeybizness

I'd check to see if it's in the coolant or coming off the remote oil filter lines...

mbb

Double post

mbb

I promise you it does one or the other.........
Have you driven behind it?

BareBonesXL

Did you leave a zero off of that 100? Maybe it's 1000? The engine can burn oil and the O2 sensor and PCM will compensate by reducing fuel.

How many miles on the engine?

Dee Veloper

Check the compression ...it probably needs new piston rings.

mbb

I had a vehicle once that used a quart of oil every 650 mi in town and every 1100 miles on the interstate. It only started smoking noticeably after 100k if you sat at idle for a couple of minutes. Ran great though and I put 40-240k on it that way with no change. Gm crewcab 5.7 tbi in 4x4 z71. Got better gas mileage than my F-150 4x4 screw with 5.4 ever has too.

RickyRazor

Check around the oil filter to see if you see oil. My oil filter housing gasket has been leaking about a quart every 200 miles and never dripped on the driveway.

dontherogue

If you're leaking that much oil and nothing's on the driveway, where's it going? The only thing I can imagine is if it's dripping on hot exhaust parts and burning off.

RickyRazor

That is definitely a possibility! Honestly, I don’t know where it’s going! Oil is covering everything around the oil filter housing and everything underneath it. It’s just not dripping on the ground. it may only actively leak when the engines hot and I’m driving…..or there are other problems besides the leaky gasket. I’m changing the gasket today and will find out soon.