My 80 with around 280k has yet to need oil between changes in the 60k or so miles I've driven it. I change at around 10k miles and check it occasionally. The oil separator I added does pick up a little oil over time but I've been collecting it for the few years I've run the separator and it's probably about 2 oz total collected. I drive the 80 hard, tow with it, drive 75 on the interstate, etc. and I'd expect it to use at least some oil at this point.
In spite of the power/efficiency of the 1FZFE I'm really happy with mine overall and think it's a great fit for the 80. I also wanted to join in on a thread that isn't 1FZ bashing, which is a little too common on mud I think.
You may be asking the OP but on my 80 the HG and valve stem seals have been replaced along with most of the top-end, accessible seals. There's evidence of seeping around the upper pan arch/rear main but it doesn't drip to ground very often, if at all, so I haven't felt motivated to dig into that yet.
So that is good (one quart consumption in 5000 miles at 290,000 miles?) as the valve stem seals, IME, start going bad (leaking)
with increased oil consumption starting around 200,000 miles +/-.
I have 334K miles on mine and I do 6000 miles between oil changes and don't need to add oil.
As long as I drive under 75 MPH I don't use much oil. Above that and I'll use a quart in 300 miles.
Head gasket was done by dealership (PO) at 145K miles. So, I have almost 200K on this HG and head rebuild. The valve seals are starting to harden, as I will get a puff of blue smoke occasionally on start up.
232,000 miles here on my 97 and I add a quart about every 4,000 miles. She’s my DD after handing my 4Runner to a daughter. Most miles are on the freeway so maybe some of the burn is the original head and valve seals since I’ve tackled the other common oil leaks. I’m pretty blown away how this previously neglected beast handles life, love the damn thing.
My 93 is at 311k miles. The PO had the HG replaced at a dealer at 265k. I bought it at 267k. The HG job work order was passed on to me and the techs comments about minor pitting on the head so they sent it out for resurfacing. Nothing about a valve job or guides redone. I asked the PO if the head had been rebuilt, he said no just the resurfacing.
She uses just about 1 quart during a 5,000 mile OCI but the oil light never comes on. If I run it hard in steep terrain, as in second gear 55 mph a lot during a trip, consumption does increase a bit but never have I seen blue smoke, not even on start up.
Looks like your rig suffers from deficient castor angle based on the forward tilt of the diff. I guess that angle allows the oil leak to run off quickly.
So that is good (one quart consumption in 5000 miles at 290,000 miles?) as the valve stem seals, IME, start going bad (leaking)
with increased oil consumption starting around 200,000 miles +/-.
Rotella T4 15w40 typically, but this last oil change was Irving 10w30 diesel oil. Irving is one of the biggest true Canadian oil companies and they blend their own oils.
I run only diesel oils for the high zinc count due to the shim/bucket design of the valve train in these engines.
It’s funny, I figured I would have had higher oil consumption going from the 15w40 to the 10w30.
Initially I did, as I watch it closely and I have a separator on the pcv system with a clear can.
But after a couple thousand it actually slowed quite a bit, less puffs at startup.
Maybe this oil has a seal conditioner? Didn’t see anything in the oils document but this is what seemed to have happened
I have 334K miles on mine and I do 6000 miles between oil changes and don't need to add oil.
As long as I drive under 75 MPH I don't use much oil. Above that and I'll use a quart in 300 miles.
Head gasket was done by dealership (PO) at 145K miles. So, I have almost 200K on this HG and head rebuild. The valve seals are starting to harden, as I will get a puff of blue smoke occasionally on start up.