Yet, another engine oil question

[lenFeb]

In GT350 owners supplement manual about checking and adding oil:

"If the oil level is between the lower and
upper holes, the oil level is acceptable.
DO NOT ADD OIL."

I check oil in my 19 GT350 regularly. The last time I checked it was between the lower and upper holes. I change the oil 2600 ml ago with exactly 10 qt. I would like to add the oil to the top of the upper hole. But "DO NOT ADD OIL" in capital letters is holding me off. Do you think if I add oil to the top of upper hole do any harm to the engine? Logically, adding the oil to the top shouldn't be an issue, but want to check with GT350 community. I have two FP oil separators and do spirited driving. So, I think oil accumulated in the oil separators is the exact amount missing in the engine.

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[jmn444]

I think it's because not every surface is level and not everyone has enough sense to be aware of what their dipstick reads when it's actually 10 qts right after an oil change, or enough sense to know that it takes a bit of time for the oil to drain down and over filling will by far cause more problems than simply waiting till it's at the bottom line to add a bit.

I've also read (on internet so may or may not be true) that consumption for some falls off a bit as the level gets lower, which is possible IMO based on how my old airplane behaved, but I haven't had issues with my 350 so not sure it applies here.

 

[proeagles]

I wouldn't worry about it.

 

[galaxy]

@lenFeb ...The very first question to be answered is -- where is the full line on YOUR car? When you change the oil and check it, where does the level come to? Does it stop at the top of the hole or the top of the hashmarks? Or slightly below the hash marks? You would not want to fill to the top of the top hole if that's not YOUR full line. Make sense?

Follow. The. Owners. Manual.

Will it hurt anything to add to the top hole (or wherever YOUR full mark is)? No. Is it worth it? No.

And no, there is not enough oil in your one oil separator (the left one is not accumulating anything) to account for the oil loss.

To put it into perspective, you are wanting to add ounces...mere ounces...probably single digit ounces...to a 2 1/2 GALLON system. Let that sink in.

 

[Nfs1000f]

When I add 10 quarts to my car it’ll fall between 1/2 and 3/4 between the hashmarks.

 

[lenFeb]

@lenFeb ...The very first question to be answered is -- where is the full line on YOUR car? When you change the oil and check it, where does the level come to? Does it stop at the top of the hole or the top of the hashmarks? Or slightly below the hash marks? You would not want to fill to the top of the top hole if that's not YOUR full line. Make sense?

Follow. The. Owners. Manual.

Will it hurt anything to add to the top hole (or wherever YOUR full mark is)? No. Is it worth it? No.

And no, there is not enough oil in your one oil separator (the left one is not accumulating anything) to account for the oil loss.

To put it into perspective, you are wanting to add ounces...mere ounces...probably single digit ounces...to a 2 1/2 GALLON system. Let that sink it.

Thanks for the reply and your opinion on the matter.
After first oil changed, I observed that 10 qt in my engine is at the top hole mark on the deep stick.
Correct, driver side oil separator is completely dry. But passenger side is filled with exact amount of oil missing in the engine.
After I changed oil (at 1k miles) and during last 2600 miles the oil level is slowly lowering by exactly the same amount collected in oil separator. Currently I'm ate 3/4 between two holes. I understand it's not a big deal(this is not my first car. I had/have cars with turbo and superchargers when engines burn oil more than voodoo engine does). Just want to make sure if I add oil to the upper hole(10 qt level) when engine cold will not do any harm and why Ford manual stated "DO NOT ADD OIL" when oil level between two holes.

 

[RJay]

Thanks for the reply and your opinion on the matter.
After first oil changed, I observed that 10 qt in my engine is at the top hole mark on the deep stick.
Correct, driver side oil separator is completely dry. But passenger side is filled with exact amount of oil missing in the engine.
After I changed oil (at 1k miles) and during last 2600 miles the oil level is slowly lowering by exactly the same amount collected in oil separator. Currently I'm ate 3/4 between two holes. I understand it's not a big deal(this is not my first car. I had/have cars with turbo and superchargers when engines burn oil more than voodoo engine does). Just want to make sure if I add oil to the upper hole(10 qt level) when engine cold will not do any harm and why Ford manual stated "DO NOT ADD OIL" when oil level between two holes.

The dipstick is not a precision measuring device - it is a guide.

What is fairly precise is the stated oil capacity of 10 quarts.

So when you drain the system, and then add 10 quarts back in, wherever that hits on your dipstick is "Full".

It's better for the motor to be half a quart low than half a quart over.

My 2019 doesn't seem to burn any oil - but I can tell you I wouldn't even consider adding oil until it hits the bottom hole - and then I would add half a quart and continue to monitor the oil level.

 

[datadatum]

Makes me wonder what the total volume difference is between the upper and lower marks. One quart? More? Less?

I'm thinking its about one quart, as I added a quart once when my level was near the lower mark, and when I rechecked it was near the upper mark. HOWEVER, one data point measured by eyeball is not what I would hang my hat on.

 

[lenFeb]

The dipstick is not a precision measuring device - it is a guide.

What is fairly precise is the stated oil capacity of 10 quarts.

So when you drain the system, and then add 10 quarts back in, wherever that hits on your dipstick is "Full".

It's better for the motor to be half a quart low than half a quart over.

My 2019 doesn't seem to burn any oil - but I can tell you I wouldn't even consider adding oil until it hits the bottom hole - and then I would add half a quart and continue to monitor the oil level.

Do you have oil/air separators installed on yours? I have FP oil separator on my and noticed the exact amount of oil missing from the engine collected in oil separator. It's not burning oil per se.

 

[jmn444]

Do you have oil/air separators installed on yours? I have FP oil separator on my and noticed the exact amount of oil missing from the engine collected in oil separator. It's not burning oil per se.

I'm wondering, how do you know it's the exact amount of oil?

And the separators do keep that oil vapor from being sucked thru and burned out the exhaust, but it's sorta the same end result... it's nothing to worry about though, it's normal and not the same as the oil consumption issues.

 

[matthewr87]

Makes me wonder what the total volume difference is between the upper and lower marks. One quart? More? Less?

I'm thinking its about one quart, as I added a quart once when my level was near the lower mark, and when I rechecked it was near the upper mark. HOWEVER, one data point measured by eyeball is not what I would hang my hat on.

When I completed my oil change the difference between the 9th quart and the 10th quart was the distance between the lower and upper hole. So that's another data point measured by eyeball.

 

[LFG_Cory]

My understanding is that it's a quart measured between the upper and lower marks. Hence if you're oil level is below the bottom hole, add a quart. You can do a half a quart and add as needed as well.

 

[Balatgek1]

This is what one quart low looks like.

 

[lenFeb]

I'm wondering, how do you know it's the exact amount of oil?

It's really easy. I use syringe with measurement scale to remove oil from oil separator. I removed around 8 oz(1/4 quart) from oil separator. The oil level on dipstick is at 3/4 between lower and upper hole. Distance between lower and upper holes equates one quart. Hope this explained.

 

[lenFeb]

This is what one quart low looks like.

After my oil change with 10qt the oil mark was at exact upper hole. Not at upper hash mark like in your picture.

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