The Math isn't lining up

[LINUS]

I think the sensor is very old. This has happened several times so I am happy about it. I don't mind getting a 1 quart warning.

This is a foreign concept to me.

I’d sooner buy a new sensor to replace my 20yr old one, and pop the hood on the regular. Check that oil like a freak.

A vegan started this thread, so we know what he values in biological health.

If you’re not that healthy or age has taken its’ toll, do you skip blood pressure meds or any organ-regulation RX’s your GP prescribes? -No, you want some quality of living.

Treat your vintage 80 like that & just find a repeatable routine to check the oil/coolant & do a brief inspection. These things are getting geriatric in general, they need the love to not show you geriatric “episodes”.

How you treat your 80 has a direct effect on how it shows reliability back at you.

 

[LINUS]

Well, just to add more mystery. I don't have any leaks. And exhaust is clean, no burning oil. I was wondering if maybe it just doesn't like synthetic?

I am hoping @flintknapper is right.

Unless you tried to break in a new motor using synth oil, this is highly unlikely.

Our conventional wisdom locally is to bed in a motor on dino oil, then after a minimum of ~7500mi+ make the switch to synth - BMW found out the hard way shipping the early V8 that replaced their venerable I6 motors circa ~’06. They spec’d 0-40 M1 oil from memory, the rings never bedded to the sleeves in the AL block. So tried bedding on synth was a full fail.

Same story for Jap bikes/quads - everyone bedded on dino, then would swap to synth. Biggest example from ownership was the ‘04 Yama R6 I owned. It shipped w/ dino and a footnot to not swap oil too soon. It had a redline that was 2x a 1FZ. No kidding, it would love a 2-3 shift at 10K/70mph & rocket you to new worlds - it was crazy but also better than bad sex.

Back to the BMW - It never bedded & also blew oil out all the gaskets to atmosphere - so new owners had oil burning, oil dripping $55K-$90K BMW’s. Google will back my story.

I’m even super concerned over my LS3 - it was spec’d w/ M1 synth from new, but it is a whole new animal to Bowtie V8’s - coolant is Dexcool that is reverse flow in the jacket from older V8’s, and I rev the snot out of mine (marine app, runs a 3 stage jet) - so hard to believe but it is what my warranty spec’s.

I run M1 10-30 & the big Napa 1515, I **might** use 1/8qt between ~3500mi changes, but still check my oil easily every ~20hrs or runtime & my 80 drops oil out the FR main seal plenty to be a dime in a week, or a quarter in a month if I just use the remote start & it sits running in place for 4-5 warm-up & cooldown cycles / monthly between real road drives.

Mine changes oil more on calender time than road miles, I run it on the remote start regularly/weekly but I drive the Tundra as my DD & boat hauler.
I’ve downsized my fleet to the point my 80 is pure pleasure & vacation /recreation event driver.

 

[clx16]

I only check my oil once a week, I do it Fridays. I get gas at only one gas pump at one gas station which doesn't have covering, so the check the oil while getting gas doesn't work for me. But an overly sensitive oil level sensor isn't that big of a deal in my opinion.

 

[LINUS]

I only check my oil once a week, I do it Fridays. I get gas at only one gas pump at one gas station which doesn't have covering, so the check the oil while getting gas doesn't work for me. But an overly sensitive oil level sensor isn't that big of a deal in my opinion.

DON’T check it then. Take it home & let it sit.

It’s just like a big chunk of cooked meat. You need to let it rest for the fluids to settle & rest. It reads more accurate/slices & serves way better meat.

No recipe for good cooked meat says “slice it the minute you pull from heat” - same rule for dipping your oil, let it drop from the head down to the pan.

 

[clx16]

same rule for dipping your oil, let it drop from the head down to the pan.

That is a good point especially for the 80. and as @offroadvegan mentioned getting different readings, I only get those while checking hot. It will also like to read very high on the first wipe when it is hot. As a rule on any vehicle i have, the first read isn't the one I would go off of.

I think for DD keeping an eye on oil pressure, keeping it in the hashes (between Full and Low marks) and changing regularly is just fine, however With all the inclines and slow speeds dealing with wheeling, I personally feel best for it to be not even a half quart low.

I haven't dropped my oil pan though so maybe when i get a better idea of where the pick up is and what angles might impact it, i might change my thoughts on that.

 

[baldilocks]

Does the owners manual not dictate how much oil is needed to accomplish an oil change? I have always simply put in what the book said and in nearly 40 years of doing my own oil changes on numerous different vehicles, tractors, mowers and countless pieces of industrial equipment have I ever ruined an engine. This forum needs an Over Thinkers Anonymous group.

 

[offroadvegan]

Does the owners manual not dictate how much oil is needed to accomplish an oil change? I have always simply put in what the book said and in nearly 40 years of doing my own oil changes on numerous different vehicles, tractors, mowers and countless pieces of industrial equipment have I ever ruined an engine. This forum needs an Over Thinkers Anonymous group.

Well my only reason for bringing it up in the first place is that it can be a harbinger of doom.

 

[flintknapper]

I’m a little dubious of this.

We filled pumpcases with gallons of oil & would hit the mark dead on, when run the oil never grew over the mark.

Regardless, I say just develop your own repeatable way to dip the oil @offroadvegan

I personally give it ~20mins after hitting self cleaning to let the oil drop down out of the case, so I don’t get a false low like if you pop the hood at the gas pumps.

You are dubious that oil undergoes thermal expansion or that it would account significantly for a lower reading on the dipstick?

It would depend of course on the temperature differences...(and to some degree the oil) but if I were to check my oil (2 gallons) when it was hot (arbitrarily 180°F) and then again when it had cooled to 70°F...I would expect to see a volume difference of about .4 qt. (thermal expansion coefficient being .00039).

Naturally .4 qt is not going to show up much on a dipstick, but would certainly be recognizable in a container.

In the OP's case...it is important to recognize you are not going to drain ALL the oil out of your engine. The Crankcase yes. And as you say (I agree completely), 'develop a repeatable way' to check your oil level, sage advice.

Volumetric or Cubical Expansion Coefficients of Liquids

Bottom line: Being marginally under or over with your oil level is of no consequence. The engine (in all it's forms) is remarkably durable and engineered recognizing it will be subjected to extreme operating conditions at times (heat, off camber angles, steep angles of ascent and descent). The engine doesn't give a pee-diddly if its a half a quart under or over. That is fodder for the OCD.

 

[REKCUT]

Well my only reason for bringing it up in the first place is that it can be a harbinger of doom.

And somewhere like all forums, this one has become less tolerant. If you have a question search and ask. If you don't like the question then move on.

Probably guilty myself

 

[LINUS]

This forum needs an Over Thinkers Anonymous group.

Well my only reason for bringing it up in the first place is that it can be a harbinger of doom.

Ummmm, you’re kinda making his point for him.

No salt intended, but you already said you knew you weren’t burning or blowing oil - so at some point we all just need to have faith in either our own work or have a strong wallet.

@flintknapper - the fact of a significant swing in dipstick readings just purely based on oil temp.
If I read your post right, you say we should see nearly a 1/2qt swing (4/10qt) just based on temp from ~50* to a warm operating temp?
-If that was so, the 4” tube we fill to that 3/4 full mark should rise an amount that would be visible (we didn’t). By the design, the sightglass was empty the 1st gallon & the 2nd gallon was what would rise that 3” in the 4” window of the sightglass/tube.

Like I’d mentioned, the sightglass on the pumpcases had a mark at the 3/4 full level & we’d fill to that mark with ambient temp Delo from 55gal drums. Pure coincidence the normal sized cases held exactly 2gal so similar quantity to a 1FZ.

The process acid was run in the 180*-190* range so the oil would hit that as well - we didn’t see any rise on that sightglass from ambient to that 180* the oil would get to. The only time we saw it rise was if the seal blew and then sulfuric acid would turn the oil a telltale purple color as it slowly wept in the bearing crankcase.

Or, since all pumps had a spare - if they weeped oil into the process pipe while it sat idle then the turbidity would froth the oil, but again not a issue of thermal expansion & you saw bubble/froth in the sightglass window. The oil was Delo 40 weight just like some guys drop in their 80’s.

Not saying it doesn’t happen, but us watching pump levels through sightglasses is what I’m basing my skepticism of large expansion when total quantity is just 2gal in the pump . I’m not a oil expert, just watched the behavior in the pumpcases.

 

[Haspin FJ]

Seems like a good time to ask a question.

My dipstick hash marks seem to be very sensitive, like a half a quart from low to high where every other vehicle I've ever owned seems lIle a full quart. Is this normal? Messed with me for a little while when I first got my 80 especially with the 8 qt capacity.

Second is agreeing with the post talking about breaking in with Dino oil (specifically the part about mid 90's bikes/quads). I had a Honda 300EX I switched to full synthetic right after purchase and always had starting troubles until a year or two later after I jumped it into a lake. Started perfect from then on after that untraditional "break in", lol.

 

[flintknapper]

Ummmm, you’re kinda making his point for him.

No salt intended, but you already said you knew you weren’t burning or blowing oil - so at some point we all just need to have faith in either our own work or have a strong wallet.

@flintknapper - the fact of a significant swing in dipstick readings just purely based on oil temp.
If I read your post right, you say we should see nearly a 1/2qt swing (4/10qt) just based on temp from ~50* to a warm operating temp?
-If that was so, the 4” tube we fill to that 3/4 full mark should rise an amount that would be visible (we didn’t). By the design, the sightglass was empty the 1st gallon & the 2nd gallon was what would rise that 3” in the 4” window of the sightglass/tube.

Like I’d mentioned, the sightglass on the pumpcases had a mark at the 3/4 full level & we’d fill to that mark with ambient temp Delo from 55gal drums. Pure coincidence the normal sized cases held exactly 2gal so similar quantity to a 1FZ.

The process acid was run in the 180*-190* range so the oil would hit that as well - we didn’t see any rise on that sightglass from ambient to that 180* the oil would get to. The only time we saw it rise was if the seal blew and then sulfuric acid would turn the oil a telltale purple color as it slowly wept in the bearing crankcase.

Or, since all pumps had a spare - if they weeped oil into the process pipe while it sat idle then the turbidity would froth the oil, but again not a issue of thermal expansion & you saw bubble/froth in the sightglass window. The oil was Delo 40 weight just like some guys drop in their 80’s.

Not saying it doesn’t happen, but us watching pump levels through sightglasses is what I’m basing my skepticism of large expansion when total quantity is just 2gal in the pump . I’m not a oil expert, just watched the behavior in the pumpcases.

Interesting. So clearly the under the conditions you describe there was not thermal expansion on the order of .00039 else it would have been evident in the displacement level of the sightglass. We assume there were graduations or some other notable mark. Naturally not all oils or additives will expand at the same rate, but what you describe compares favorably with what I run in mine.

Naturally, I am inclined to favor empirical evidence over the 'published numbers' (not mine by the way) of other sources. So I am with you. I don't offer the thermal expansion thought as 'fact', too many variables..just a possible reason for some of the disparity.

I'll go with your experience on this one.

 

[mudgudgeon]

Seriously, take your wifes panties off before checking the oil.
It's not that complicated. Most of my girlfriends over years have managed to learn it!

If you've got the correct dip stick, wipe it clean, push it all the way home, remove, check, repeat.

a litre/quart above, or below the full mark is sweet. That gives you a 2quart margin before it drops below Low, then another what before the oil sensor is triggered.

Run it for couple of minutes after an oil change, otherwise, check it hot, cold, after 5min, after 20 min, after filling the tank, whatever. It's going to make f-all difference, soand long as it's not significantly lower time you check. and you have a 2 quart margin.

 

[LINUS]

Interesting. So clearly the under the conditions you describe there was not thermal expansion on the order of .00039 else it would have been evident in the displacement level of the sightglass. We assume there were graduations or some other notable mark.

As for the sightglasses, they all get that ‘notch’ from the manufacturer (1/4, 1/2, 3/4) -marks on the acrylic tubes, brass fittings that are the 90* ends & bulkhead the pumpcase.

So wouldn’t that .00039 translate to 3.9%? - I’m asking as that seems more in line with what water I’d ballpark expansion (prob a bit more, IDK) when you freeze it- I’m just moving the decimal 2 places to get percentage = .039 which in my head makes 3.9% - I’m simply putting that out there, since 3.9% on a sightglass where a gallon moves it 3” would fall in line with our not seeing any change visually on the ~1/16” wide hash marks on the tube.

Thinking out loud, feel free to disagree - esp on my math is I’m trying to interpret that .00039 number into what the real world has shown me in a situation that mimics our quantity & temp range really well.

Even in our bigger compressors that hold easily 40gal oil, we only see about a 1/4” differential from cold & not running to hot & in service - but IDK from the few times we tore down the compressor (we only had 3 that size, and I wasn’t rated to lead that overhaul like the common 2gal sump acid process pumps) - so IDK when the sightglass saw oil or what amount made the glass move any amount.
Those also had 10” tubes & in service the norm was to lose 1/8” in a 12hr shift for the operators - we just left a 55gal drum & a air transfer pump next to those compressors since they had their own buildings.

 

[Tedward]

Well I learned something here.
Not about checking my oil for goodness sakes.

I've only heard Canadians use f-all. Now I know it's used in Australia as well. Good to know.

 

[thatcabledude]

Just curious.... OP, which dipstick does your truck have? The "wire rope" style or the flat type? IMO, the flat type on the 1fz doesn't read worth a damn.

 

[sbman]

I wouldn't use a 'high mileage' oil on anything. The oil has added chemicals to soften and swell the seals in the engine and may contribute to additional wear on the seals. Regular synthetic oil without that crap in it would be preferable. I don't understand how 'high mileage' oil became so prevalent. It's getting harder and harder to find plain oil on the shelf. If there are already leaks then I guess it doesn't hurt to try it but on a rebuilt engine? no way.

 

[pawnthatdude]

The Mud standard maintenance schedule: check your oil at every sufficiently long stop light (always carry at least 16qts of extra oil, just in case), grease your u-joints at every fill up (only using grease made of Toyota brand unicorn sweat), change your transmission fluid on the full moon (must be done at night, or else it won't drain right), and check your bearing preload every time you use reverse.

For extreme conditions (anything farther than 5 miles past your nearest mall), do all of this twice as often.

 

[offroadvegan]

Just curious.... OP, which dipstick does your truck have? The "wire rope" style or the flat type? IMO, the flat type on the 1fz doesn't read worth a damn.

It's the cable type. Really inconsistent.

 

[offroadvegan]

I wouldn't use a 'high mileage' oil on anything. The oil has added chemicals to soften and swell the seals in the engine and may contribute to additional wear on the seals. Regular synthetic oil without that crap in it would be preferable. I don't understand how 'high mileage' oil became so prevalent. It's getting harder and harder to find plain oil on the shelf. If there are already leaks then I guess it doesn't hurt to try it but on a rebuilt engine? no way.

The only reason I went with that was that it was the only 10-30 full synth on the shelf. I didn't think it made much of a difference. Apparently, I was wrong.