Normal oil consumption level 1FZ-FE, 200k maintenance schedule recommendations

[Tinglemd]

New here!

I’m running a 97 Collector’s Edition that I’ve owned for about a year and put close to 10k worth of smiles on. The Odometer is showing 191k. I’m currently adding a quart of oil every 2,000 miles or so. I tried a heavier weight diesel oil this last oil change, but didn’t seem to make much of a difference. Is there a “normal” level of oil consumption that I should expect in this engine at this age, or should I consider any oil consumption unacceptable? Previous owner fixed what was broken, but I doubt performed any preventative maintenance. What should I be looking to do at the 200k mile mark to keep this truck healthy and happy?

Thanks for your help!

 

[jeffro109]

Your consumption isn't horrible but isn't great either. Typically, a healthy engine will be less than a quart per oil change (say 3,000 miles or so) and you are somewhat above that. You might try a high mileage oil that has some additives to see if any seals can be made to swell and seal better. Valve seals are a likely point of leakage as is piston rings. You could double check that you don't have any large external leaks too. Your consumption level is not so high that I would personally worry about expensive repairs if you don't mind adding oil, if it gets to less than 1,000 miles when you need a quart, it might be time to really consider more in depth repairs.

 

[jpoole]

You are likely burning oil because of leaky valve stem seals. From what I've observed reading here and with my own 1FZ, valve stem seals are the leading cause for oil consumption in an otherwise healthy 1FZ with various leaks likely coming in 2nd for oil loss.

My '97 1FZ with a little over 300k miles on it uses no noticeable oil and I haven't needed to add oil between oil changes in the last 87k miles, since I replaced the valve stem seals as part of a head service / head gasket / etc. job. I do oil changes at fairly large intervals (6k to 7k miles typically) and run Rotella 15/40. Driving includes both city and longer, high speed hwy runs including towing a 3k lb camper occasionally.

 

[Kernal]

Ditto: most likely valve stem seals. Been discussed a lot in the past (helps to use the Search function, top right of each page).

Toyota apparently says that up to one quart of oil usage per 1000 miles of driving is considered "normal" however as mentioned in the post above when the engines are new or after the valve stem seals have been replaced the oil consumption goes to about zero per 5000 miles, IME.

Could send a sample of used engine oil to a lab for an Engine Oil Analysis (Blackstone Laboratories for example). It could give some indication of worn rings, cylinder wall scuffing etc which can cause an increase in wear metals (ppm) in the sample. Worn valve stem seals won't do that.

Trivia: switched one of my 80's from Mobil 1 10W-40 to Chevron XSP 400 Full Synthetic 15W-40 (API SN Plus approved for Gasoline engines and should have less phosphorus than some other Diesel oils so maybe safer for the Cats??). Oil consumption went down maybe 30% after switching to the XSP 400 15W-40 but that 80 is due for new valve stem seals. FWIW

 

[BILT4ME]

When you drive, how fast do you drive and what is your RPM range?

I find if I'm on the highway running 78 MPH, I'm about 2800 RPM consistently. Wwhen it downshifts for a hill, I'll hit 3600 RPM. During those times of extended high RPM, I suck a lot of oil because it's pumping more oil on top of the head that can get sucked in through valve seals and it can get deep enough that then PCV valve starts to suck more oil.

I have found that if I slow down 10 MPH and lower my RPM about 400 RPM, my oil consumption will drop to almost zero.

I have a particular route across KS that is a 3 hour one way drive and I have experimented with this a lot. In three hours one way at the higher speed, I will burn a quart of oil in those three hours.
If I drive at the lower RPM, I will not burn enough oil to change the register on the dipstick in the same direction on the three hour trip.

I have 374K miles and the head was rebuilt at 145K, so it's due for valve seals again. I'm seeing a puff of blue smoke at startup and when accelerating from a light. Typical of valve seals.

If you get a constant blue smoke while driving, that would be rings.

 

[robnicko]

your consumption is on the high side but likely the valve stem seals as others mentioned. Observe at nightime when taking off when a car is behind you, normally see the smoke from the headlights
All engines can consume a small amount of oil, its normal

you may want to check the PCV Valve to ensure its not blocked however based on the mileage does very much sound like the VSSeals

Since doing the HG on mine and full valve / seal service it doesnt use any oil, just a small leak from the front oil pump cover
Prior to the HG it was using a good 1 litre between oil changes (8000km / 5000mi between changes)

 

[LandCruiser105]

+1 from me on the valve stem oil seals. After I changed these out during a HG replace in 2022, the oil consumption dropped to almost negligible levels from previously needing a litre every 1-2k. If leaking, the other places can be oil pump o ring seal, or crank rear seal. I'd have thought you'd readily spot an external leak at that level of loss though.

 

[Tinglemd]

Wow! Thanks so much for all the good info. Yes, I’ve checked for visible leaks: She’s dry as a bone. The burn rate at higher RPMs makes a ton of sense to me. I just took a 5+ hour road trip to the beach with extended highway travel at 70+ average speeds. I bet that did it. Valve stem seals seem the most likely culprit, so I’ll start planning for that repair. Adding oil doesn’t bother me, and I always carry at least 2 quarts just in case, so no rush. concerning a 200k preventative maintenance scope, does anyone have opinions on what should be done just because, even if there are no known issues?

 

[LandCruiser105]

Well, if you are doing the valve stem seals these can be done with the head off or in situ and there are threads on here about how to do that. If you decide to remove the head, and whilst you are in there... well you could make quite the list depending on your appetite for work and depth of wallet...!

Good things to consider would be checking & resetting valve shim clearances, replacing water hoses, spark tube oil seals, water pump and thermostat etc. Watch out for aging electrical connectors that often are very brittle and break on disassembly - I ended up replacing a few of these, some because I had to.

Many would just accept the oil burn and add the oil - I didn't really have a choice about pulling the head as my HG was on its way out.

 

[bj70bc]

PHH (pesky heater hose) is a known thing on these

 

[azusa]

With a articulating boroscope you'll be able to see if the oil is coming down the valves or up the piston rings. Just saw on Amazon for about $55, that's after a coupon. Also if you remove the boot off the throttle body, sometimes oil pools up, that would indicate rings also, as long as the PCV valve is working correctly.