1fz-fe Oil Consumption Issue

[enox]

I took a trip from CA to CO this past week. Total mileage for the trip was 1971mi driven, my 80 consumed approx 10qts of oil. I had really difficult time climbing any of the inclines on the freeway and even on the flats it was a struggle to hit 65mph, with the speed limit of 80 being out of the question. I do have an oil catch can which surprisingly didn't have much in it upon my return. I did an oil change while up in CO as well since from CA i ran mobil 1syn 5-30, switched in CO to the black bottle castrol syn 5-40, tried to add 2 qts of the Lucas oil stabilizer throughout to see if that would help with consumption.

Here at some notes;

238k mi on the 80 - Blue fan clutch, PHH done, factory HG. emission system good and recently passed CA smog inspection.
No noticible consumption while in CO on the trails.
Freeway struggle to hit speed limit
Freeway uphill struggle (i understand that the transmission is usually looking for gears however fighting to get up-hills)
approx consumed 1qt oil every 140-190mi.
friend who followed me, advised of black poof of smoke when on grades either during downshift or at the crest of a hill.
i have no leaks on the motor
new Toyota pcv valve
oil catch can which was less than 1/4 full after the trip.
highest engine temp recorded in the desert was 213.
no check engine light popped up.
oil pressure remained normal and high.
added oil either when the light came on or when i checked the stick and noticed it was low.

I've done long CA trips and have not had an issue with consumption until this trip.

super thankful that the 80 got the dog and i home safe after a long week.
trying to figure out weather to repair of v8 swap, since the goal of this rig is to travel/camp and wondering for the rest of you, if you travel great distances do you drive faster than 65mph?

 

[BILT4ME]

Black smoke on acceleration is fuel
Blue smoke on deceleration is valve seals
Blue smoke on acceleration is piston rings
Blue smoke upon acceleration from a stop sign is valve seals
White smoke on deceleration is head gasket
White smoke on acceleration is head gasket

Some oil consumption is covered up due to the catalytic converter. It will burn it off and make it invisible.

I would look at vacuum leaks, and particularly valve cover seal and spark plug tube seals that could be causing the excess oil consumption and loss of power.

Struggling to make 65 MPH on the flats indicates other more serious tuning issues. What is your past maintenance? Spark Plugs, Wires, Dist. cap and rotor, vacuum hoses and leaks, fuel filters and sock?

Have you confirmed your O2 sensors?

You do not mention the year, as that can affect some of the diagnosis based on OBD1 or OBD2.

 

[enox]

Black smoke on acceleration is fuel
Blue smoke on deceleration is valve seals
Blue smoke on acceleration is piston rings
Blue smoke upon acceleration from a stop sign is valve seals
White smoke on deceleration is head gasket
White smoke on acceleration is head gasket

Some oil consumption is covered up due to the catalytic converter. It will burn it off and make it invisible.

I would look at vacuum leaks, and particularly valve cover seal and spark plug tube seals that could be causing the excess oil consumption and loss of power.

Struggling to make 65 MPH on the flats indicates other more serious tuning issues. What is your past maintenance? Spark Plugs, Wires, Dist. cap and rotor, vacuum hoses and leaks, fuel filters and sock?

Have you confirmed your O2 sensors?

You do not mention the year, as that can affect some of the diagnosis based on OBD1 or OBD2.

Sorry its a 1995!!

My cats looked good when i changed the muffler a few weeks ago and ran a scope up the pipe to check em out. (Side note)
Had a valve cover gasket done last year due to a leak, did spark plug tube seals at the same time. Recently brought back to the shop since valve cover gasket was leaking (it was replaced at no charge)
replaced spark plugs/ wires and complete distributor late last year, along with fuel filter in engine compartment and in tank. replaced all the vacuum hoses with new silicone ones. Cleaned TB and idler/ replaced rubber intake hose.

i have not confirmed o2 sensors aside from using my "ultra gauge" and seeing that they produce values. i am unsure exactly how to diagnose.

 

[scottryana]

Pull your spark plugs, and take some pictures.

At 1 quart every 140-190 miles that is a quart per 10 gallons, you are basically burning 40:1 2 stroke mix in your truck.

Could be spark plug seals, or rings, check the plugs and do a leak down test.

 

[BILT4ME]

Totally agree with @scottryana for the next step in diagnosis.

 

[enox]

ok thanks - ill pull the plugs when i get a little time and respond with some pictures. ill also double check all hoses and vacuum lines. at least now since its summer here is a good time for me to dig into it before next winter.

 

[Travis 76]

I have a 1994 before my head gasket blew I would use about a quart of oil a month. Some burning some leaking. Always had power though. I drive 80-95 mph through Utah from Las Vegas to Salt Lake City. All stock hearing and tires. Now basically no oil consumption, after head gasket redo.

 

[enox]

I have a 1994 before my head gasket blew I would use about a quart of oil a month. Some burning some leaking. Always had power though. I drive 80-95 mph through Utah from Las Vegas to Salt Lake City. All stock hearing and tires. Now basically no oil consumption, after head gasket redo.

wow yeah, I was struggling to do 65... stock gearing on 33's which were aired up too.

it took me an eternity to get through Vegas and Utah... 17hours from CO back to CA.

 

[Tools R Us]

...
highest engine temp recorded in the desert was 213.
...

How long is a piece of string? What was the typical cruising and climbing temp? We have noted that the engine tune is affected, reducing power, at some point over ~200F. Once this happens the reaction is to push the throttle, putting more load, making it worse...

Were you anticipating climbs, shifting to keep the motor in the power band, if not, having the motor bogged at low RPM will make it worse. For big climbs, ~4000rpm is the sweet spot. But the fix is to get the cooling system in a condition where it will reliably run at less than ~200F.

This doesn't fully account for the oil consumption. But typically highest consumption is at full loaded highway travel. If running hotter than needed, the oil is thinner, expansion causes clearance gaps to open, etc. In desert conditions we run 15W-50 with good results.

 

[bhsdriller]

I probably burn a quart every 1,000 miles or so. Maybe even less.

It'll still go as fast as I want (80+) and does good on climbs. Well as good as it could lol

 

[flintknapper]

" I was struggling to do 65 "

Definitely something amiss. Hope you find out what it is.

A normal Speed Limit sign should be something we adhere to and not a 'Goal'.

 

[enox]

How long is a piece of string? What was the typical cruising and climbing temp? We have noted that the engine tune is affected, reducing power, at some point over ~200F. Once this happens the reaction is to push the throttle, putting more load, making it worse...

Were you anticipating climbs, shifting to keep the motor in the power band, if not, having the motor bogged at low RPM will make it worse. For big climbs, ~4000rpm is the sweet spot. But the fix is to get the cooling system in a condition where it will reliably run at less than ~200F.

This doesn't fully account for the oil consumption. But typically highest consumption is at full loaded highway travel. If running hotter than needed, the oil is thinner, expansion causes clearance gaps to open, etc. In desert conditions we run 15W-50 with good results.

my motor struggled to get past 3200rpm. most of the drive it was at 2200-2400 because it didn't feel right. the ultra gauge noted that most of the drive the engine was between 42-56% engine load flat and even on the climbs, i would drop down to the 20% range when on the downhill.

i actually didnt know the LC could get up to 4k rpm.

i have a new denso radiator/hoses and blue fan clutch along with t-stat.

most of the climbs were between 199 and 205 degree while climbing. i only saw 210+ in the desert during mid day...

 

[enox]

" I was struggling to do 65 "

Definitely something amiss. Hope you find out what it is.

A normal Speed Limit sign should be something we adhere to and not a 'Goal'.

View attachment 2018940

this is great, i didnt know the 80 was capable of adhering to the speed limit signage!

 

[Tools R Us]

my motor struggled to get past 3200rpm. most of the drive it was at 2200-2400 because it didn't feel right. ...

That combined with high consumption, may point to a tired motor, what are the compression numbers?

 

[flintknapper]

this is great, i didnt know the 80 was capable of adhering to the speed limit signage!

Kidding aside, mine has 310K on it. Running 33's. Original Head Gasket.

I haven't ever tried to see what the 'top speed' is with it, but I've had it over 90 mph once just for the fun of it (then backed off) and regularly hit 80+ mph when passing a group of vehicles on the highway.

I don't often 'floor it' but my shift points are just a tad under 5K when I do, so yes...when everything properly adjusted and running right...you shouldn't be struggling.

 

[Tools R Us]

Yep, mine is stockish, 37"s and a lift, will cruise past the speed limit, as long as I can maintain momentum, will clear most climbs at 60-70mph.

 

[enox]

thats awesome, i too should check compression after going through some of the other things... will start with pulling the plugs.

 

[BILT4ME]

thats awesome, i too should check compression after going through some of the other things... will start with pulling the plugs.

Compression test (Wet and Dry)
Leak Down test
Check TPS
Check O2 sensors

Limiting to 3200 RPM would make me think clogged cats or improper throttle cable and trans cable adjustment and/or TPS adjustment.

 

[MoJ]

Or, clogged cats because it’s burning oil like crazy...

 

[BigGreenTractor]

Step one: consult fsm follow diagnosis procedures.