Oil level reads high on dipstick

[roegs]

I purchased my truck new and have done 2 oil changes myself. In both cases I drained on a level surface (my garage floor - very slight slant towards rear of truck) and let it drain to a slow drip. 12 quarts of oil were then added. Each time resulted in the dipstick reading high as shown in the photo. Couple additional thoughts:

- I believe the dipstick showed the same level for the factory fill. I'm about 90% certain on this.
- One of the other forums mentioned that these trucks are very sensitive to levelness as far as the dipstick is concerned. My truck has the air suspension and sits about 2 inches lower in the rear than a truck with standard rear suspension. I jacked the rear of the truck up a couple of inches but there was no appreciable change in the dipstick reading.
- My understanding is that the safe range on the dipstick represents 2 quarts. If so, I'm about 3/4 quart high. Is this even a concern?
- Could the dipstick itself be off in its length?

 

[superjoe83]

I purchased my truck new and have done 2 oil changes myself. In both cases I drained on a level surface (my garage floor - very slight slant towards rear of truck) and let it drain to a slow drip. 12 quarts of oil were then added. Each time resulted in the dipstick reading high as shown in the photo. Couple additional thoughts:

- I believe the dipstick showed the same level for the factory fill. I'm about 90% certain on this.
- One of the other forums mentioned that these trucks are very sensitive to levelness as far as the dipstick is concerned. My truck has the air suspension and sits about 2 inches lower in the rear than a truck with standard rear suspension. I jacked the rear of the truck up a couple of inches but there was no appreciable change in the dipstick reading.
- My understanding is that the safe range on the dipstick represents 2 quarts. If so, I'm about 3/4 quart high. Is this even a concern?
- Could the dipstick itself be off in its length?

I have not done the first change on my '22 yet, but when I changed my '18 I never put the full 12 quarts in, even letting it sit for an hour to drain with the filter off, I usually ended up with about 11.5 to 11.75 to read full on the dipstick after sitting for about 30min on flat ground

 

[roegs]

I have not done the first change on my '22 yet, but when I changed my '18 I never put the full 12 quarts in, even letting it sit for an hour to drain with the filter off, I usually ended up with about 11.5 to 11.75 to read full on the dipstick after sitting for about 30min on flat ground

Assuming that your '22 still has the factory fill in it, does it show high on the dipstick?

 

[superjoe83]

Assuming that your '22 still has the factory fill in it, does it show high on the dipstick?

It was slightly over full when new, now with about 4k miles it has dropped to about a 1/8" below full and seems to be holding there

 

[Truckman]

I wouldn't worry about the dipstick except as a check reference as to whether it uses oil or not. I put 12 qts in when changing as Cummins says and never worried about it.

 

[jetrinka]

How long after running the truck to fill the filter are you waiting to check the level?

 

[roegs]

How long after running the truck to fill the filter are you waiting to check the level?

Not quite sure I'm understanding your question. It's been over a month since I last changed oil and the level on the dipstick (cold) is the same.

 

[jetrinka]

If you’re checking it after it’s sat overnight it will always read overfull because you’ve given the oil time to completely drain from the head and other areas of the crankcase. Check it after the oil is hot within a minute or so after shutting the engine down and I’d bet it’s perfect

 

[roegs]

If you’re checking it after it’s sat overnight it will always read overfull because you’ve given the oil time to completely drain from the head and other areas of the crankcase. Check it after the oil is hot within a minute or so after shutting the engine down and I’d bet it’s perfect

Hmm....what your saying may be true, but the manual (For 2021 its page 398) says that the oil should be checked at least 30 minutes after a fully warmed engine is shut off.

 

[jetrinka]

Hmm....what your saying may be true, but the manual (For 2021 its page 398) that the oil should be checked at least 30 minutes after a fully warmed engine is shut off.

Weird. Not sure why they’d say that. I can guarantee there isn’t a professional mechanic in the world that waits a half hour to check the oil level.

On my cars I change the oil, run it to fill the filter, wait about a minute and when I check it’s always right at the full line. 7 quarts in my Hemi which is spec. If I waited 30 minutes it would read over full. Never had an issue on my 01 CTD either.

 

[superjoe83]

Weird. Not sure why they’d say that. I can guarantee there isn’t a professional mechanic in the world that waits a half hour to check the oil level.

On my cars I change the oil, run it to fill the filter, wait about a minute and when I check it’s always right at the full line. 7 quarts in my Hemi which is spec. If I waited 30 minutes it would read over full. Never had an issue on my 01 CTD either.

If I checked mine right after shutdown it would show close to the add mark, I have noticed after working on these 6.7's and it's larger brother the 8.9 ISL, the oil filter will be siphoned off to about half full after sitting for about a half-hour, that is why cummins/ram recommends checking after 30 min to allow time for that oil to make its way to the pan for consistency in the oil level.

 

[jetrinka]

If I checked mine right after shutdown it would show close to the add mark, I have noticed after working on these 6.7's and it's larger brother the 8.9 ISL, the oil filter will be siphoned off to about half full after sitting for about a half-hour, that is why cummins/ram recommends checking after 30 min to allow time for that oil to make its way to the pan for consistency in the oil level.

Wouldn’t it be the opposite? I’d want a full filter so I don’t get false readings in the pan from a half drained one.

If it’s true what you say and checking right after running results in a close to the full mark and waiting a half hour results in (roughly) a quart over full - I’d say both are normal conditions

 

[H3LZSN1P3R]

Weird. Not sure why they’d say that. I can guarantee there isn’t a professional mechanic in the world that waits a half hour to check the oil level.

On my cars I change the oil, run it to fill the filter, wait about a minute and when I check it’s always right at the full line. 7 quarts in my Hemi which is spec. If I waited 30 minutes it would read over full. Never had an issue on my 01 CTD either.

The cummins will always read low if checked too soon its been that ways since 89 when they started putting them in the rams the filter stays full its just the oil coming back down from the head as it pools up top.


OP dont worry about it thats very normal and to be completely honest i never check the oil after changing it until about a week after. I know i put 12Qt in so its going to be full and i know it does not drip or burn oil…. You are fine being a bit over full as long as its no more than 2qt over its plenty fine

 

[AH64ID]

This has always been a debate over the years, probably since ‘89. The capacity of the motor is 12 quarts, but that doesn’t mean it’s the oil change quantity. Between the design of the oil pan and residual oil in the block(mostly the head) only 11-11.5 quarts will drain out when you change the oil, even if it sits until it stops dripping.

That means when you add 12 quarts it will be slightly overfilled. Some trucks register this and some don’t. Mine have always sat right at, or under, the full line when parked in my shop. I usually check it after being parked at least overnight. The ‘05 got 14 quarts (had a 2qt bypass filter), the ‘18 and ‘22 get 3 gallons.

All the oil filters I’ve used have drained back into the pan, but the OEM filter seemed to be emptier than I am used to with the Donaldson filter. That’s another factor in how the dipstick reads after the prescribed 30 minute sit.

The temp and viscosity of the new oil, combined with 3 gallon jugs vs 12 quarts jugs, will also have a minor effect on oil being poured into the truck. The residual oil doesn’t add up to much, but it does add up if you take the time to ensure it’s all poured in.

Some engines have such a difference in the initial oil fill vs the oil change amount that they are different published specs, like an automatic transmission thou not as huge a difference. Most are close enough that they don’t bother.

Bottom line is that the most important thing is to note your oil level and to know if it’s decreasing or increasing. Check it the same every time.

 

[Cseybert]

The best time to change your oil is after it sat overnight, not warmed up. On the 5.9‘s that was always the case. The only time I changed it when it was not sitting from all night I ended up adding 3/4 of a quart more getting old I guess on my 6.7 19 and 22 same goes for that, just my experience.

 

[AH64ID]

It really shouldn’t matter for changing it.

Either way you have to let it drain for a while, so go with what your schedule allows. I’ve done both and never noticed a difference on where 3 gallons gets me. When it’s hot you’re waiting for it to drain to the pan and when it’s cold it takes longer for the pan to drain. When it’s cold you could miss draining things out that have settled to the bottom of the pan.

I prefer to work on a cool to warm motor thou.

 

[roegs]

Thanks for all the replies. This question about 6.7 oil capacity is on many forums and there seems to be many answers. Some guys say their dipstick registers full with 11 quarts, some say 11.5, others say its dead on at 12 quarts, and there were a couple saying 13 quarts. This engine has shown an oil capacity (with filter) of 12 quarts for many years, and that appears to be how a majority of oil changes are done. Certainly with dealers, they’re gonna drain and refill with 12 quarts. When I bought this truck, one of the things I liked about the Cummins 6.7 was its simplicity vs Ford and GM diesels. I believe part of that simplicity is easy oil changes with a nice round number of 12 quarts. Every other vehicle I've owned (and I've had my fair share) you re-fill with the number of quarts specified in the Oil Capacity section of the owner's manual.

So why doesn’t everybody’s dipstick show full with 12 quarts? I guess that’s kind of the $100 question. Couple of variables I can think of:

Drain with vehicle at an angle – After looking at this oil pan I believe you’d need to be at quite an obvious angle to not get all the oil out. The design is such that its all going to flow towards the large drain plug.

Too short of a drain – If you let it drain to a slow drip, I again believe its gonna drain it all out. The pan is large and it takes time to let the oil clinging to the surface of the pan drain out, but by then the bulk of the oil is long gone.

Difference in dipstick length – just a quarter inch difference in this long dipstick could account for differences.

Difference in dipstick tube length – not too sure on this.

Not checking oil with cold level engine.

I’ve posted pictures of my dipstick alongside a measuring tape. I measured from where the dipstick meets the tube to the end. If any of you have time on your hands, I’d be interested to see if yours measures the same.

 

[dslbrnr]

11.75 qts in mine reads full. I put the remaining in my MF tractor.