My oil level is going up??? Really need help

[Nick1424]

Currently at a loss. Information overload incoming. I document all my maintenance all work in general for the vehicle. As it sits the car has 9,949 miles and I bought it brand new. It’s a 2024 mustang gt that is currently my daily as I’m searching for a second vehicle. Only mechanical mods are a catback and upr passenger and driver side catch cans. Everything has been smooth and the car runs great, doesn’t consume oil, and my Blackstone reports have been good. Car has had two oil changes to date done by myself Amsoil sig series 5w-30. After closely monitoring on a weekly basis and exhibiting no oil consumption and passing 5000 miles I moved to checking my oil once a month as I felt I had a benchmark established. Well on 5/9/25 the day of my second oil change I checked it after driving the car and getting it up to temp then giving it a 15 minute wait following manufacturer instructions and got the picture you see here

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With work and a hectic schedule I missed my June check by 1 day but checked it on July 1st and noticed an increase following the same guidelines warm engine shutdown and wait 15 minutes. Here is that photo

And finally where I am today I checked it again photo attached 7/3/25

Whatever I’m experiencing is also visible on the cold side. I have photos of my level cold on 5/10 the next day after the oil change and where it is now. It has gone up. Blackstone did note on my last report that my viscosity was slightly low but they noted it was harmless or there was no other fuel or contamination in the mix. So with all of this information I’d really like some help or what I can or should do? It’s bugging me. Yes I park in the same spot if that is a question to raise. Car is great sounds great runs great but this is confusing me.

 

[Exhaustgases]

And what does it smell like? Maybe the cap on the dip stick is slipping up.

 

[NiwradND]

my guess the car is sitting at a different angle, it should be find, if worried get it tested, but I would not worry about it if you can't smell gas in the oil. If winter, then it could be gas in the oil, but very seldom does that happen in the summer.

 

[Nick1424]

I’ll smell it tomorrow. I can’t really make out any smell I have a bottle of Amsoil that I got for reference but I can’t smell much of a difference between the two.

 

[JavierH19]

Check the oil level on the same surface and when cold. Motor oil expands a bit like atf and can read higher. Also read both sides as one side usually reads a tad higher unless it's a dip stick that goes straight down into the sump but many go into the side at an angle.

 

[Nick1424]

Check the oil level on the same surface and when cold. Motor oil expands a bit like atf and can read higher. Also read both sides as one side usually reads a tad higher unless it's a dip stick that goes straight down into the sump but many go into the side at an angle.

will do. I just wasn’t sure if environmental factors can affect that as well. Like it being really out here in Texas and making a cold reading inaccurate.

 

[Exhaustgases]

. Motor oil expands a bit like atf and can read higher.

And so does the case/pan it is in.

Oil check when cold and sitting for a long time, make sure all drained to the pan.

 

[Nick1424]

is sitting for 6-8 hrs enough?

 

[JimPghPA]

Just a guess, the filter drain back valve is intermittently or slowly allowing oil to drain out of it when sitting thereby adding to the sump as it drains out.

 

[Nick1424]

Just a guess, the filter drain back valve is intermittently or slowly allowing oil to drain out of it when sitting thereby adding to the sump as it drains out.

Is this something that could need replacing?

 

[NiwradND]

is sitting for 6-8 hrs enough?

I think 8 hours should be fine

 

[Nick1424]

I think 8 hours should be fine

Will do. Just ordered a kit from Amsoil to pull and send for testing. Whatever I’m experiencing is strange. I knew engines could consume oil. No reason for my dipstick to be going in the other direction.

 

[NiwradND]

Will do. Just ordered a kit from Amsoil to pull and send for testing. Whatever I’m experiencing is strange. I knew engines could consume oil. No reason for my dipstick to be going in the other direction.

Please report back your results, this may be a lesson for all.. Thank you and good luck.....Happy Forth of July!

 

[Lubener]

I’ll smell it tomorrow. I can’t really make out any smell I have a bottle of Amsoil that I got for reference but I can’t smell much of a difference between the two.

The only worthwhile time to check oil level is when the engine is cold before you start it. Any other way, you will get varying results.

 

[Nick1424]

The only worthwhile time to check oil level is when the engine is cold before you start it. Any other way, you will get varying results.

Is there any reason why the day after my change in may compared to a few days ago I checked it cold and there was a difference in the two levels?

 

[Nick1424]

Please report back your results, this may be a lesson for all.. Thank you and good luck.....Happy Forth of July!

Will do same to you!

 

[NiwradND]

Is there any reason why the day after my change in may compared to a few days ago I checked it cold and there was a difference in the two levels?

Was the car sitting in the same spot. A little different tilt to the car will defiantly make a difference.

 

[Donald]

And so does the case/pan it is in.

Oil check when cold and sitting for a long time, make sure all drained to the pan.

And vehicle is parked level.

 

[demarpaint]

Park it on level ground, like the inside of a garage, then check the oil first thing in the morning before starting the engine. That should tell you if the level is changing or not.

 

[Pablo]

Just a guess, the filter drain back valve is intermittently or slowly allowing oil to drain out of it when sitting thereby adding to the sump as it drains out.

This is part of it. The engine holds 10 qts. The dipstick hash is 1 qt. So we are maybe seeing 2-3% movement. This could easily be oil from filter and the entire engine, hanging up sometimes, more or less.

I would for sure next oil change do a non-Blackstone UOA, like OA and get a real fuel %.

My advice - check a bit more frequently. Exact spot (mark if necessary). Engine cold overnight. Honestly unless it just keeps going up, every day, I would not worry.