Weird oil consumption problem 1FZ

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Hello guys, starting to have a bit of a concern about my oil consumption on my 94 landcruiser. Vehicle has 212k on it now and it’s usual consumption is about 1 qt around 3-4K miles that’s with a rear main seal leak that I been putting off for some time now. Recently my brother decided to help me out by adding some oil after I noticed the low oil level light appear for a few moments on my to work that day. He added oil and forgot to put the oil cap on. My usual daily commute is about 44 miles to work and back, on the 3rd day driving to work the oil level light turned on and I thought that was weird, I got to work and open the hood to oil residue all over the valve cover/ intake area and hood insulation. I added Almost 2 qts of oil and replaced the oil cap that was sitting near the headlight. Over the past week I have added another 3 qts of oil and began to notice a oil burning odor during cold start but no visible smoke. Oil color on the dipstick also changed from yellow to black, usually my oil stays fairly clean even when I change the oil every 5k miles. I ordered a pcv valve and grommet and oil cap seal from the local dealer. Replaced the pcv and other parts on Friday along with a oil and filter change, made sure oil is topped off at the full mark. After less then 100 miles on my way home from work today I noticed the oil level light turn on again on a slight downhill. I haven’t checked the level yet but I’m concerned over this excessive consumption after something I thought would not even be a big deal. I also noticed while engine is operating temp and idling if I open the oil cap I get no change in rpm. Prior to this, opening the oil cap would cause the engine rpm to drop and engine will run rough for about 20 seconds until the idle air control adjusts. Makes me believe internal air/vacuum leaks. Sorry for the lengthy post but I’m wondering if anybody has experienced something similar. Thank you
 
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Need more information:

What viscosity of oil are you using?
How are you checking your oil level?
What rpm does your engine idle at once the engine warms up?
 
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Apr 21, 2012
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granada hills,CA
I run 5w-30 idmitsu api GF-6 oil along with 2 additive cans of liqui moly viscoplus to make it similar to a 10w-30 oil.

Oil level is usually checked cold always in the same flat parking spot and dipstick is pulled and wiped multiple times.

Operating temp idle is between 600-700 rpm
 

mudgudgeon

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Your brother let the pixies out!

Never trust brothers with cars!

After less then 100 miles on my way home from work today I noticed the oil level light turn on again on a slight downhill. I haven’t checked the level yet
Until you check the oil level, why panic?
Could be an issue with you oil level sensor wiring. Go check your oil level, and check for loose/cracked/ damaged wiring harness, or dirty connection on the oil level sensor.

In the first part of your post (can't say first paragraph, coz you slammed us with a wall of text) you say your bro added oil after a light flickered?
Did he add oil to the right level? Or overfill?

Over filling the sump is not a great thing to do.

Worn out/ hardened valve stem seals are a big cause of oil consumption in 1FZ. with the age of your vehicle, they are likely to be rock hard and not effectively sealing. A surprising amount of oil is lost this way.
Doesn't really explain a sudden loss of oil though.

I personally am not a believer in using additives in oil. Buy a quality oil of the correct grade and weight, and don't fúck with it IMHO
 
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I run 5w-30 idmitsu api GF-6 oil along with 2 additive cans of liqui moly viscoplus to make it similar to a 10w-30 oil.

Oil level is usually checked cold always in the same flat parking spot and dipstick is pulled and wiped multiple times.

Operating temp idle is between 600-700 rpm
The oil level light is a sensor in the side of the block that may or may not be accurately reading oil level.

Many of us have taken it out, installed a new o ring, cleaned up the sensor and the issue with the light coming on randomly goes away.

In other cases, like mine, that light still chooses to come on while I'm driving, when it's cold, on every third Tuesday with a lunar eclipse. The light really means nothing other than "I want attention and look at me again even though you just looked at me and everything was fine."

Use oil of the correct grade and type for your area. Additives are typically very unnecessary and some are evil. If you're doing the additives because your engine is "high mileage ", it's not. It's normal for these.

I run Quaker State 5W-30 and I put on about 20K miles per year.

Keep checking your oil level as you're doing.

With the oil level suddenly turning black, I'd bet it got terribly over filled and the serious churning of too much oil in the crankcase washed off some long term gunk. No big deal. If you're concerned, take a sample at your next oil change and send it off to Blackstone Labs for an analysis. I do this every other oil change on mine just to monitor health.

Yes, you need to check hoses for vacuum leaks if the engine is not stumbling with the oil cap off. That said, you ECU has made adjustments to the operation to adjust for the severe vacuum leaks and that's why it idles fine with the cap off.

Shut off the truck and pull the EFI fuse under the hood for two minutes. This will reset all codes and ECU settings. When you start it back up, it should go through a series of high idle, but should settle down.

Then drive it for a week and try the oil cap removal thing again. I'll bet it will stumble like it should.
 
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At around 290,000 miles mine began consuming oil at a rapid rate- a quart every 500 miles. I correctly diagnosed it as valve stem seals. Blt4me has hit the proverbial nail on the head, however, I’ve been using 15w40 for over a decade with great success . 356,000 and still running strong.
 
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Your brother let the pixies out!

Never trust brothers with cars!


Until you check the oil level, why panic?
Could be an issue with you oil level sensor wiring. Go check your oil level, and check for loose/cracked/ damaged wiring harness, or dirty connection on the oil level sensor.

In the first part of your post (can't say first paragraph, coz you slammed us with a wall of text) you say your bro added oil after a light flickered?
Did he add oil to the right level? Or overfill?

Over filling the sump is not a great thing to do.

Worn out/ hardened valve stem seals are a big cause of oil consumption in 1FZ. with the age of your vehicle, they are likely to be rock hard and not effectively sealing. A surprising amount of oil is lost this way.
Doesn't really explain a sudden loss of oil though.

I personally am not a believer in using additives in oil. Buy a quality oil of the correct grade and weight, and don't fúck with it IMHO

I been dealing with adding oil for a week or so and the oil light had been pretty accurate during the time, although I wish it was a problem with the wiring or the sensor, I just checked the oil level now after letting the car rest for 20 mins, oil level is at the bottom of the hash mark. The oil color still looked clean so there is a possibility it was overfilled before the oil change was done. I also did notice after my 22 mile drive this morning, before I parked it, I stabbed the throttle a few times in park and I noticed some visible smoke when rpm began coming down to idle. It may very well be the valve stem seals but it’s baffling that the consumption rate increased this much overnight. Having the oil cap off probably interrupted the constant vacuum on the seals and maybe a few let go.

The oil level light is a sensor in the side of the block that may or may not be accurately reading oil level.

Many of us have taken it out, installed a new o ring, cleaned up the sensor and the issue with the light coming on randomly goes away.

In other cases, like mine, that light still chooses to come on while I'm driving, when it's cold, on every third Tuesday with a lunar eclipse. The light really means nothing other than "I want attention and look at me again even though you just looked at me and everything was fine."

Use oil of the correct grade and type for your area. Additives are typically very unnecessary and some are evil. If you're doing the additives because your engine is "high mileage ", it's not. It's normal for these.

I run Quaker State 5W-30 and I put on about 20K miles per year.

Keep checking your oil level as you're doing.

With the oil level suddenly turning black, I'd bet it got terribly over filled and the serious churning of too much oil in the crankcase washed off some long term gunk. No big deal. If you're concerned, take a sample at your next oil change and send it off to Blackstone Labs for an analysis. I do this every other oil change on mine just to monitor health.

Yes, you need to check hoses for vacuum leaks if the engine is not stumbling with the oil cap off. That said, you ECU has made adjustments to the operation to adjust for the severe vacuum leaks and that's why it idles fine with the cap off.

Shut off the truck and pull the EFI fuse under the hood for two minutes. This will reset all codes and ECU settings. When you start it back up, it should go through a series of high idle, but should settle down.

Then drive it for a week and try the oil cap removal thing again. I'll bet it will stumble like it should.
Unfortunately the light was correct and it was low, however I do need to reseal the sensor as I have noticed there is some seepage from that area.

I use the liqui moly additive because 10w-30 oils are getting far less common, most of them being high Milage oils with seal swellers and other additives. I will try the next oil change running a straight 5w-30 and see what the dummy oil pressure gauge says.

I have done a oil analysis a while back but a current one won’t help with a consumption issue.

I will try the ecu reset now so it can relearn the values. Thank you


At around 290,000 miles mine began consuming oil at a rapid rate- a quart every 500 miles. I correctly diagnosed it as valve stem seals. Blt4me has hit the proverbial nail on the head, however, I’ve been using 15w40 for over a decade with great success . 356,000 and still running strong.

Can the valve stem seals be done with the cylinder head still on? Like a SST from Toyota for doing it that way maybe.
 
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I been dealing with adding oil for a week or so and the oil light had been pretty accurate during the time, although I wish it was a problem with the wiring or the sensor, I just checked the oil level now after letting the car rest for 20 mins, oil level is at the bottom of the hash mark. The oil color still looked clean so there is a possibility it was overfilled before the oil change was done. I also did notice after my 22 mile drive this morning, before I parked it, I stabbed the throttle a few times in park and I noticed some visible smoke when rpm began coming down to idle. It may very well be the valve stem seals but it’s baffling that the consumption rate increased this much overnight. Having the oil cap off probably interrupted the constant vacuum on the seals and maybe a few let go.


Unfortunately the light was correct and it was low, however I do need to reseal the sensor as I have noticed there is some seepage from that area.

I use the liqui moly additive because 10w-30 oils are getting far less common, most of them being high Milage oils with seal swellers and other additives. I will try the next oil change running a straight 5w-30 and see what the dummy oil pressure gauge says.

I have done a oil analysis a while back but a current one won’t help with a consumption issue.

I will try the ecu reset now so it can relearn the values. Thank you




Can the valve stem seals be done with the cylinder head still on? Like a SST from Toyota for doing it that way maybe.
Yes, the valve seals can be replaced with the head still in place. Need to remove the cams and the valve shims, then pressurize each cylinder with compressed air and you can pull the valve springs and keepers out from the top with the right tools.
 

mudgudgeon

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I will try the next oil change running a straight 5w-30 and see what the dummy oil pressure gauge says
5w30 would not be recommended for a 1FZ at all.

10w30 or 15w40 would be better depending on the climate where you are.
In really cold regions, you might need different grades summer and winter, but I'm sure this isn't likely the case in Cali

5w is to light, your asking for problems.

A lot of people are using a diesel grade oil as it will have more detergents in it and will clean sludge and carbon out.
Any chance your bro or a diesel grade oil in?
It may explain the dark colour.

It's also probably a good idea do do a compression test before you treat into that engine, just to eliminate another issue like failed rings.
I'd also probably pull the spark plugs, and see if you have any that stand out as being oiled up
 
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5w30 would not be recommended for a 1FZ at all.

10w30 or 15w40 would be better depending on the climate where you are.
In really cold regions, you might need different grades summer and winter, but I'm sure this isn't likely the case in Cali

5w is to light, your asking for problems.

A lot of people are using a diesel grade oil as it will have more detergents in it and will clean sludge and carbon out.
Any chance your bro or a diesel grade oil in?
It may explain the dark colour.

It's also probably a good idea do do a compression test before you treat into that engine, just to eliminate another issue like failed rings.
I'd also probably pull the spark plugs, and see if you have any that stand out as being oiled up
I disagree.

My LC states right on the 710 cap to use 5W-30.

That's what I've been running for the last 141K miles.
 

mudgudgeon

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Oh rly?

Screenshot_20221123-064353.png
 
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The Australian FZJ80's apparently got a different owners manual than the US model where in the US Toyota specs 5W-30 while in Oz they spec 10W-40 for the about the same temperature range. During past discussions on this topic it's been assumed the US mileage regulations may have something to do with that difference. IIRC the Oz FZJ80's also didn't get the EGR system the US vehicles are plaqued with.

Having said that I also noticed dramatically increased oil consumption in my 96 FZJ80 starting around 225,000-250,000 miles, a puff of smoke on hard acceleration more visible at night with headlights from another vehicle behind mine. Using a higher viscosity oil than recommended decreased oil consumption somewhat.

FWIW
 
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IIRC the 93-94 1FZ recommends 10w-30 and 95-97 is 5w-30. Yes I have also heard about the oil viscosity for outside of US being in the 10w-40 range.

I purchased new plugs from the dealer and going to do a compression check while I’m in there. Took the air filter out for replacement when I noticed a pool of oil in the intake hose so I pulled that off to more oil in the throttle body.

85863B27-202B-4C97-80AF-8FDB5D35BE09.jpeg
 
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Mobil 1 10W-40 High Milage significantly reduced my oil consumption. It won't help with bad rings, but it will if your problem is old, hardened seals.

As for the 10W vs 5W debate, lower is better. As long as the second number is at least as high as recommended for your environment, the only difference with a lower first number is that oil will flow better when cold. 0W-40 is what I would run if I didn't have so many old, hardened seals.
 
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IIRC the 93-94 1FZ recommends 10w-30 and 95-97 is 5w-30. Yes I have also heard about the oil viscosity for outside of US being in the 10w-40 range.

I purchased new plugs from the dealer and going to do a compression check while I’m in there. Took the air filter out for replacement when I noticed a pool of oil in the intake hose so I pulled that off to more oil in the throttle body.

View attachment 3175378
Change your PCV valve, grommet and hose to OEM
 

COYS

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Knock on wood, 100% new OEM long block now 13K miles young, zero oil consumption, 85-90mph hwy power no sweat on 37s. Broke it in with many 3-4K RPM sustained pulls on trips to LA-SLC-LA-SEA-LA. Bombed up Grapevine Southbound at 80-85mph with AC on, overdrive off. EZ.

5W-30 Pennzoil Ultra Platinum all day. Why? It's on the oil cap dum dum.

Topping off is a drag. Had to do it on the og engine. No mas!

 
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IIRC the 93-94 1FZ recommends 10w-30 and 95-97 is 5w-30. Yes I have also heard about the oil viscosity for outside of US being in the 10w-40 range.

I purchased new plugs from the dealer and going to do a compression check while I’m in there. Took the air filter out for replacement when I noticed a pool of oil in the intake hose so I pulled that off to more oil in the throttle body.

View attachment 3175378
Blowby is common with older engines (not recently rebuilt). That's why some are fitting oil bypass systems to catch it. I just rebuilt the head on my son's 1995 80. I had to replace a leaking injector (O-ring failure) at 500 miles. The spotless intakes I installed after the rebuild were already dripping with oil.
 
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I been dealing with adding oil for a week or so and the oil light had been pretty accurate during the time, although I wish it was a problem with the wiring or the sensor, I just checked the oil level now after letting the car rest for 20 mins, oil level is at the bottom of the hash mark. The oil color still looked clean so there is a possibility it was overfilled before the oil change was done. I also did notice after my 22 mile drive this morning, before I parked it, I stabbed the throttle a few times in park and I noticed some visible smoke when rpm began coming down to idle. It may very well be the valve stem seals but it’s baffling that the consumption rate increased this much overnight. Having the oil cap off probably interrupted the constant vacuum on the seals and maybe a few let go.


Unfortunately the light was correct and it was low, however I do need to reseal the sensor as I have noticed there is some seepage from that area.

I use the liqui moly additive because 10w-30 oils are getting far less common, most of them being high Milage oils with seal swellers and other additives. I will try the next oil change running a straight 5w-30 and see what the dummy oil pressure gauge says.

I have done a oil analysis a while back but a current one won’t help with a consumption issue.

I will try the ecu reset now so it can relearn the values. Thank you




Can the valve stem seals be done with the cylinder head still on? Like a SST from Toyota for doing it that way maybe.
I went ahead and pulled the head, shop said the specs were just as good as new, cleaned everything up and reassembled.
 

FMC80

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IIRC the 93-94 1FZ recommends 10w-30 and 95-97 is 5w-30. Yes I have also heard about the oil viscosity for outside of US being in the 10w-40 range.

I purchased new plugs from the dealer and going to do a compression check while I’m in there. Took the air filter out for replacement when I noticed a pool of oil in the intake hose so I pulled that off to more oil in the throttle body.

View attachment 3175378
This happened to my 94 cruiser after I changed the PCV, grommets, VC gasket, etc.

The cause of the oil in the TB was my VC gasket being torn and letting a shît load of oil escape
 

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