Detroit 671 TIB Oil Levels

Generally the dip stick is scored when the oil is changed the first time to account for the mounting angle, and that 45* angle sounds like that was done. I'd trust the stick for now. And yes put in some oil and let it settle. Next time you change the oil check that the stick was marked correctly. Also the stick could be bent, giving you incorrect levels if someone along the way forced it in rather than finessing it in. No way to tell for sure on any of it though until your next oil change. So I see no alternative but to trust the stick. On the up side Detroits always leak. So if you over fill a bit it'll level out.

671s hold a tremendous amount of oil in the galleys for a long time. Including the turbo lines and blower.
Are you checking the oil cold or some short time after the engine was running?

I check my 12V71TIs oil cold in the morning before use. Ad to the full mark.
If they were run, a hour later they will read low. Next morning read fine.

Further 28 qts sounds high. Please offer your serial number to a real DDC shop for the factory sump cap spec.

So are you saying you can get ALL the oil out and put in a known quantity to verify the dipstick? My experience is that the amount of oil you are able to get out varies considerably.

Detroit sticks are factory stamped. The dip tube is at factory length.

An over filled engine will whip the oil, inducing to much foam/air in the oil. Engines blow up from this.

I have kept my 6-71 oil level half way between full and low for many years. When the yard fills to the line it just consumes it until it hits the half and stays there.

Ran my 8V71TI's the same way for 30 years. When filled up to the full mark in the old days before airseps it would just puke out 2 quarts immediately into my blow-by collectors. Between L & F on the dipstick represented about 4 quarts. So I eliminated the waste and the mess and just kept them at the halfway mark to begin with.

We run all our 671's 1/2 gallon low for the same reason. I run my 6v92's almost a gallon low and don't have to add oil between changes.

Mine too

Hello Matt Clark. I hope we did not chase you away.

Someone mentioned that the factory marks the dip stick. Almost every motor manufacturer does that, even my lawn mower. Then the mechanic on installation (or the owner) who wants to know his oil level marks his stick after putting in the factory spec amount of oil. When the motor is built it's sitting level as it will in most trucks and heavy equipment. Maybe not so in a marine application. When you change your oil next time run the motor for a few minutes to circulate the oil through the filter, wipe the stick, let it sit for a day, then take a file and mark the line where it'll work for you. If the dip stick has been pinched all the more reason to put your own mark on it. What good does a factory fill mark do if it doesn't mark the correct fill level for your motor in your application?

Matt, looks like you have an Ocean? J & T motors?
I've got 471 TIs and to me it looks like J & T marked my sticks or they were replaced by previous owner?
Anyway I always check mine next morning or 8 hours later for a proper reading like Capt Ralph said. It takes time for all the oil to drain back into the pan.
I run my motors on full, with no leaks or great consumption . I hold just under 5 gallons. That being said I have heard about what the others have said, and those who run them on the half way mark.

Not all motors are factory market. CAT's and Cummins are marked by the installer and replacement DD sticks come blank and have to be marked. A lot of motors will consume oil if they're at the Full mark, due to the boat's angle when running etc. etc. .....I've found many like to be at 2/3 above low......

The full mark should keep you from overfilling. The important mark is the one you put about 20% down the stick from there. Anywhere in between is fine, and yes some motors blow some of that out and prefer to be down a few quarts. Nothing wrong using that mark, but I'd put a mark at factory spec so I could better figure the low mark.