Luca Signore

Hey everyone,

My 91 22RE truck with a 5 speed and 195k miles has been burning a moderate amount of oil recently. I filled it up to the F line on the dipstick and after about 1000 miles, it is below the L line.

I did a compression test to see if there was anything major - 170 psi on all 4 cylinders. All plugs look brand new still. I looked under the hood but could not find any obvious leaks. Let it idle for 5 minutes over a big piece of cardboard and not a drop. Only thing I did notice was that my PCV valve had a lot of oil in it and the grommet is really worn/cracked. I have a new valve and grommet on order, but I'm not sure where to go from here. The truck does not smoke, but I do have a pretty significant amount of black buildup on the exhaust tip. Engine sounds good and runs well - no knocking, good power, no hesitation. I'm just confused now.

Does this scream of anything obvious? Valves need adjustment? PCV? EGR? I'm using 10w-30 Valvoline synthetic blend high mileage if that matters.

Thanks for any help you all can offer.

millball

A quart in a thousand miles in an engine with 200,000 miles is not excessive.

I wouldn't be concerned until consumption approaches a quart in 500 miles, or issues with spark plug fouling appear.

A slightly heaver viscosity oil might help. Try a 10W-40, or if you live where ambient temps stay mostly above freezing, a 20W-50.

Luca Signore

Makes sense. Am I safe to assume from the F to the L line is about a quart?

I live in California so temperatures rarely if ever drop below 32. Is there a benefit to using conventional rather than synthetic?

millball

Yes, F to L is about a quart.

Well, conventional oil is less expensive, and just as good in your old engine. Millions of these engines have run as long, and longer on nothing else.

You might consider using a high detergent diesel spec oil like Rotella, or Delo

scope103

I used to have a car that used a quart of oil a month. And that was just to keep the doors from squeaking!

I agree with Millball. You've probably got not-unexpected wear in the ring sealing surface, and you're just slowly burning up the oil. Stopping that would probably be a big deal (re-boring the block, replacing the pistons, that kinda stuff), but at 1 qt/1000 miles you're not likely to have a catastrophic failure. Just keep a qt or two of plain-ole oil in the back, and check the oil each time you buy gas. You'll probably be fine for another 50,000 miles. Or not.

13Swords

If the PCV grommet is worn/cracked, you likely have the original PCV valve in it, which could be stuck closed. That could cause some excess pressure in the crankcase & pushing oil where it normally would not go, causing the oil burn/consumption. Get your new valve & grommet in & see if the oil use changes after that.

ptr1968

These old engine run better with a bit thicker oil, use 5W50 or even 10W60 oil.

peter

old87yota

I would simply just keep an eye on the oil level (check each time you fill up for gas, or about that interval), and replace the worn PCV valve and grommet. Chances are that the valve guides, valve seals, and piston rings are a little worn and allowing oil to enter the engine when running. As others have said, I would not worry about the consumption much at this point; just keep an eye on it.

I would personally keep using the factory recommended 10W-30 or 10W-40 oil that you have been using. You can use either conventional, synthetic, or a blend of the two. If you decide to go with conventional, don't think that it will cause excessive wear. These engines were not designed with modern synthetics so they don't benefit as much as a brand new Tacoma. I am never a fan of using "thick" oils to reduce oil consumption. Sure, you may be losing less oil, but the engine is not getting lubricated as well (particularly at cold startup), and would increase wear.

MaK92-4RnR

My 3vze is at 248k? Original block with about 50k on the top end and it's burning about a quart-ish between oil changes. I just face the facts that the block itself is over 30 years old, it's been used and abused and the best thing that i can do for it is to simply add oil between the full flush and keep on keeping on. I use Castrol 10w40 High mileage since it's the most optimal weight/viscosity for.Northern California's temperatures.

Co_94_PU

iTrader: (-1)

This is one of the additives in high mileage oils, HM has higher detergent factors and seal conditioner.

You'll want to reduce the miles/hours between oil change the first few times. It's going to go nasty really fast.

You might also find that it reduces the oil consumption a bit if you have sticky rings.

3x on the pcv valve it with help with crankcase pressure.

RAD4Runner

I was losing about the same on my 22RE but because of combination of valve cover gasket leak and some around the oil pump. I have fixed the former but the latter may take extra work. Yesterday's oil change I filled with conventional 10W-40, too. Will see how that affects the oil pump leak.

wallytoo

iTrader: (1)

i've lived with similar oil loss/use in my #1 '87 4runner for nearly 100K miles. doesn't bother me, and i keep a spare quart in the engine compartment (fits nicely between the driver side headlamp and the air filter box). virtually no leaks, either from the valve cover, rear main, or oil pump, so it is losing the oil internally via burning. plugs/wires also have over 50K miles on them, and are still in great condition. still consistently run 19 to 22 mpg depending on how i'm driving. i do run 10w-40 or 15w-40 in the winter (we see some -20*F days), and 20w-50 in the summer.

for my #2 '87 4runner (with the freshly rebuilt 22re), i haven't seen any oil loss. i'm running 5w-30 in that one. haven't run it enough to get good mpg data.

rattlecanpaint

My '85 4runner uses a bit of oil as well. I just substitute a quart of Lucas oil stabilizer and it drastically reduced oil usage.

Jimkola

If it makes you feel better, a quart of oil per 1,000 miles is close to Toyota's oil consumption guidelines bitd ( 1,200).

The best test(s) for oil consumption is the compression test (mostly to make sure the cylinders are all even), and the leak down test. Most chain parts stores with loaner tools will have leak down testers available. The leak down test is by far the most informative. Like a compression test, you want to see the % of all cylinders pretty close. A healthy 22r usually had numbers around 10%. The make or break number was 20%. Numbers higher than 20% indicated something needed to be done(i.e. overhaul).

If it looks like rings are the culprit you can try Rislone. I'm not a fan of most additives, but I've seen Rislone do some amazing things. Do a oil change, and add the Rislone with the new oil. Works even better if vehicle goes on long drive afterwards. After 1,000 miles I'd change the oil and filter and see if there's improvement(and get fresh clean oil in the crankcase). Sometimes a second application helps. I've never seen a third treatment do much more, so after two I'd stop. If the rings were just stuck from oil sludge Rislone will most likely help. Weak or broken rings, not so much.

44K can be effective, but to be honest, I've seen Rislone work better at a fraction of the price. It's worth a shot considering the next step is engine removal. And please run the tests before pulling the engine. It's worth having the data so you know what to scrutinize once the engine comes apart.

Luca Signore

Hey - thanks for the information.

Is there a specific leak down tester you would recommend? I don't think O'Reilly loans them out and the Harbor Freight one has mixed reviews. My compression test was 170-175 psi on all 4 cylinders.

Jimkola

Keep in mind, I’m not recommending any kind of disassembly. The leak down could give you a very good idea of where the concern might be. Here’s a article I found a minute ago that mirror’s my earlier post https://www.carbibles.com/leak-down-test/#forward .
We always used OTC at the dealer, but I think they're just ok these days, at least the consumer brand. You could find a ok kit on Amazon.
The more I ponder this, though, the more I'm thinking your oil rings on the pistons are stuck. Valve stem seals are a possibility, but I think the oil rings are more likely. And tests aren't going to show issues with oil rings or valve stem seals. I'd try the cleaner with a fresh oil change. If valve stem seals are the issue it won't help, but it could very well unstick oil rings on the piston.

Luca Signore

Yeah I've had good luck with OTC in the past - their kit is about $70 online. For a good cleaner, would you recommend the Rislone you mentioned above? I've heard of decent results with Seafoam.

Jimkola

I use SeaFoam when I store away my generators for the winter, and it seems to do a good job of preventing varnish and stabilizing the gas so it doesn't turn bad. I tried SeaFoam once to clean out the Onan carb on our RV when it sat too long, and it didn't work very well. Then we tried it on our neighbor's RV with the same issue and it did work. So 50/50. But I've never tried it in the oil before, always the gas. I think when added to oil you have to change it out pretty fast, though. Maybe a few hundred miles? Rislone can stay in much longer, just watch the level. Regardless, change it out with fresh oil after 1,000 miles. Odds are you oil is going to be very black anyway. At this point you can just add oil and drive it for 1,000 miles and see what improvement you have. If it's down you can add another bottle of cleaner.
I hope this works. Adding oil isn't the end of the world, but it does get tiresome to always monitor. And opening up an engine just snowballs financially.