Technical_Driver

This is a continuation from my build thread here but to keep it short I am losing a quart of oil approximately every 800 miles. 1985 Toyota Pickup 22RE-C 57,400 original miles.:

https://www.yotatech.com/forums/f198...-miles-287309/

On to trying to diagnose the oil issue. I had a trusted mechanic check the truck. He stated the compression on cylinder 1 was 140 and 2,3,4 were all less than 90 psi. This came as a surprise as again the truck seemingly runs perfect. I have taken this truck up to 90mph on the highway and it idles smoothly at around 800 RPMs. Doesn't have any misses at idle.

He told me that I would need an engine rebuild (keep in mind the truck is sitting at 57k miles) but ok, yeah, the truck sat for years inside of a garage maybe the oil rings are stuck on 2,3,4.

Got the truck home and tested the compression myself with two separate gauges and turning the truck over 4 times with throttle wide open per FSM instructions on checking compression.

Cylinder 1 read 180
Cylinder 2 read 175
Cylinder 3 read 175
Cylinder 4 read 175

While this would seem to be damn good news I now have an issue as to what in the hell is wrong with my truck. I'm not going to knock the mechanic as he comes highly recommended in the off road community.

Here are pictures of the spark plugs from each cylinder (I can only upload 3 but the fourth is the same). These plugs were changed at 52,800 miles so this is how they look after 4,650 miles.

No oil leaks out onto my garage floor but the tailpipe is sooty and black possibly indicating blowby out of the exhaust. If this is the case though why are the plugs clean.

wyoming9

iTrader: (1)

Are you getting the blue oil smoke when driving or when the engine is at idle.

This truck sat for a few years unused just how many miles has it been driven with the use of a quart in 800 miles ??

quite possible the valves have some rust so the valve seals are not sealing like they should

Give it a few thousand miles see if they seal or time to do some head work

Just what plugs are you using a hotter then normal plug will burn the oil.

I would guess you have checked for oil in the cooling system??

No oil trail along the underneath of the truck like a rear main seal??

What was done to your head when the engine was rebuilt ??

It is either burning or leaking

If it is not leaking and your 100% sure pretty much is gonna be in the head

You are checking the oil after it has had time to drain back into the oil pan??

Oil being unable to return to the oil pan for what ever reason.

jimbyjimb

iTrader: (1)

Exhaust is black and sooty, hence the tailpipe being black and sooty.

Burning that much oil you should have a smoking issue. As was suggested, valve seals are a likely culprit. If that isn't it oil rings could be suspect.

If it has been sitting much of its life the valve seals are a logical place to start.

thefishguy77

iTrader: (1)

Valves more than likely if no leak. Seafoam is kinda like the dr for these trucks. Maybe run some through your fuel system. They also say it can be run in the crank case (oil). On the bottle. Keep driving it and if it doesn't fix itself (it is a Toyota) then maybe seafoam the oil. Also with good compression if it is a stuck valve or rusted ect. Then you could just order a new head from engnbldr for a few 3-400 bucks and not worry about the problem anymore. Just an option. Good luck hope it fixes itself.

Technical_Driver

I don't notice blue smoke at idle but that does not mean it isn't there. The tailpipe is black and sooty as if it was a diesel engine.

The truck has been driven 7,500 miles roughly since I got it.

You guys seem to agree it is valves or seals. I am going to continue down this path. I'll be trying out the Seafoam.

I put in new plugs per the FSM NGK BPR5EY. Not sure if these are hotter than normal or not.

Cooling system is clean and free of oil.

Not a drop of oil under the truck my garage floor is clean.

Engine has not been rebuilt it is the original engine with 57,500 miles.

I wait to check the oil and give it time to properly drain back into the pan.

Thanks for the suggestions If it doesn't work itself out with time I'll try to see if I can't get the valve seals replaced or at least properly checked.

lonfu

Did you check the PCV valve to make sure it is rattling around? they can't be cleaned out, they must be replaced. If stuck open they can suck oil. If not a problem then it is your valve guide seals.

1985 22r carb 4x4 complete drivetrane rebuild and a 93 2x2 kingcab.

Some times you can soften the valve guide seals by using/driving the engine, warming them, but the best is to replace them. They just get hard after a while.......

58rennur4

iTrader: (1)

What weight oil are you running? On my 198000 mile rig at 5w/30 anymore I have that kind of oil consumption. However, I use 10w/30 and add one quart of Lucas Oil Treatment and burn none....