Perplexing oil level
Thread Starter
Melting Slicks
Joined: Feb 2018
Posts: 2,152
Likes: 1,031
From: North Texas
Perplexing oil level
I have a 2017 WET SUMP LT1 engine. When I check the oil level I get two different readings depending on what side of the dip stick I read. The difference is almost 1/2 qt, ie: full on one side and half ways down on the other side of the stick.
I usually wait until the engine is fully cooled off, next day, so all the oil should have drained down into the pan and give a reading of the same time period of engine off.
Please remember this is a WET SUMP and not a Z51.
I have a hard time imagining the dip stick is entering the pan at such a drastic angle to effect the dip stick reading to this much difference between the front vs the back of the stick.
Has anyone experienced this perplexing oil level reading?
Does anyone understand the reason why and can explain it? i would really like a technical answer.
Always been this way since new.
I usually wait until the engine is fully cooled off, next day, so all the oil should have drained down into the pan and give a reading of the same time period of engine off.
Please remember this is a WET SUMP and not a Z51.
I have a hard time imagining the dip stick is entering the pan at such a drastic angle to effect the dip stick reading to this much difference between the front vs the back of the stick.
Has anyone experienced this perplexing oil level reading?
Does anyone understand the reason why and can explain it? i would really like a technical answer.
Always been this way since new.
Thread Starter
Melting Slicks
Joined: Feb 2018
Posts: 2,152
Likes: 1,031
From: North Texas
Checking the service manual showed the dip stick and tube. It had a number of curves and bends but no hint to as to what would cause the discrepancy on fill level.
Still looking for an answer.
Still looking for an answer.
Safety Car
Joined: Mar 2006
Posts: 4,536
Likes: 5,123
From: Chester VA
No idea about the different readings, but do you change your own oil? If so, after the pan is completely drained and then the crankcase filled with what you know to be exactly the correct amount of oil, take a spin around the block, let the engine cool and all oil drain back into the pan, and then check your dipstick reading. If it still gives you two different readings, ignore it - it's 'normal' for your car.
Racer
Joined: Jan 2022
Posts: 446
Likes: 35
From: Central Florida
The dipstick likely sticks into the oil at an angle. The surface tension will cause the oil to wick up the side of the dipstick that’s closer to the oil, where it and the oil surface make an angle less than 90 degrees. I have an old school big block Chevy in my hotrod and it’s the same way.
Melting Slicks
Joined: Jun 2019
Posts: 2,010
Likes: 910
From: near philly
The dipstick likely sticks into the oil at an angle. The surface tension will cause the oil to wick up the side of the dipstick that’s closer to the oil, where it and the oil surface make an angle less than 90 degrees. I have an old school big block Chevy in my hotrod and it’s the same way.
like he said ^, the dipstick HAS TO go in at a really steep angle otherwise you'd be a quart low before you could even notice a change on the stick
That's how they make them so that one quart moves the level on the stick over an inch
Thread Starter
Melting Slicks
Joined: Feb 2018
Posts: 2,152
Likes: 1,031
From: North Texas
The dipstick likely sticks into the oil at an angle. The surface tension will cause the oil to wick up the side of the dipstick that’s closer to the oil, where it and the oil surface make an angle less than 90 degrees. I have an old school big block Chevy in my hotrod and it’s the same way.
High side or low side?
When reading the level after being off for ~12 - 14 hrs (overnight) I get the two different levels.
I also get the two different levels even if I pull the stick, clean it, insert it and immediately remove it. No time for oil to wick up the stick.
I can visual see the angle theory, still high or low which is correct?
Or is the correct level the middle of the two sides?
Last edited by Tinkertech; Aug 29, 2022 at 11:17 AM.
Safety Car
Joined: Mar 2006
Posts: 4,536
Likes: 5,123
From: Chester VA
So what would be the correct level?
High side or low side?
When reading the level after being off for ~12 - 14 hrs (overnight) I get the two different levels.
I also get the two different levels even if I pull the stick, clean it, insert it and immediately remove it. No time for oil to wick up the stick.
I can visual see the angle theory, still high or low which is correct?
Or is the correct level the middle of the two sides?
High side or low side?
When reading the level after being off for ~12 - 14 hrs (overnight) I get the two different levels.
I also get the two different levels even if I pull the stick, clean it, insert it and immediately remove it. No time for oil to wick up the stick.
I can visual see the angle theory, still high or low which is correct?
Or is the correct level the middle of the two sides?
Racer
Joined: Jan 2009
Posts: 395
Likes: 194
From: Goderich, ON
I have noticed same, it must be the angle of the tube entering the sump because I've checked oil level twice 10 seconds apart with the dipstick positioned 180* differently each time and lower side of dipstick shows more oil than the top. I use the high side for reading.
I've had other engines do this also but it's more pronounced with a tubular shaped dipstick probe.
I've had other engines do this also but it's more pronounced with a tubular shaped dipstick probe.
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Thread Starter
Melting Slicks
Joined: Feb 2018
Posts: 2,152
Likes: 1,031
From: North Texas
After an oil change and putting in 7 Qts the level is over the hash marks on one side but lower on the other side.
Right now I have 6 Qts and 8 Oz in the engine ( I drained 24 Oz, 8 Oz at a time ) and the high side is now on the top hash mark and the low side is on the 2nd hash mark from the bottom. Which one would be correct?
On my Lexus the stick goes straight in and always reads the same on each side so I can see an angle making a difference.
Right now I have 6 Qts and 8 Oz in the engine ( I drained 24 Oz, 8 Oz at a time ) and the high side is now on the top hash mark and the low side is on the 2nd hash mark from the bottom. Which one would be correct?
On my Lexus the stick goes straight in and always reads the same on each side so I can see an angle making a difference.
Thread Starter
Melting Slicks
Joined: Feb 2018
Posts: 2,152
Likes: 1,031
From: North Texas
Thread Starter
Melting Slicks
Joined: Feb 2018
Posts: 2,152
Likes: 1,031
From: North Texas
Thread Starter
Melting Slicks
Joined: Feb 2018
Posts: 2,152
Likes: 1,031
From: North Texas
No idea about the different readings, but do you change your own oil? If so, after the pan is completely drained and then the crankcase filled with what you know to be exactly the correct amount of oil, take a spin around the block, let the engine cool and all oil drain back into the pan, and then check your dipstick reading. If it still gives you two different readings, ignore it - it's 'normal' for your car.
Thread Starter
Melting Slicks
Joined: Feb 2018
Posts: 2,152
Likes: 1,031
From: North Texas
I have noticed same, it must be the angle of the tube entering the sump because I've checked oil level twice 10 seconds apart with the dipstick positioned 180* differently each time and lower side of dipstick shows more oil than the top. I use the high side for reading.
I've had other engines do this also but it's more pronounced with a tubular shaped dipstick probe.
I've had other engines do this also but it's more pronounced with a tubular shaped dipstick probe.
Could explain this a bit more, I don’t fully understand what you are saying.
Melting Slicks
Joined: Mar 2013
Posts: 3,104
Likes: 626
From: Baton Rouge LA
After changing the oil to your spec (e.g., 6.5 qts.), check the dipstick level on each side. That is your correct level, so from then on gauge your oil level based on that observation.
Melting Slicks
Joined: Mar 2013
Posts: 3,104
Likes: 626
From: Baton Rouge LA
The following is my opinion and not everyone will agree: My GS uses no measurable oil between changes, so if yours behaves likewise you could check it now and that would be the fill standard. I wouldn't depend on a dipstick check on one car necessarily being exactly the same on another. Mine is a dry sump and I fill with nine quarts (9.8 is spec and many owners use 9.5), so at that or any other time it shows ~1/3 into the hash marks. That's my fill standard, but like I said it never changes measurably thereafter.
Thread Starter
Melting Slicks
Joined: Feb 2018
Posts: 2,152
Likes: 1,031
From: North Texas
Except I just read the high and low readings on the stick and take the average
