[Big Monk]

Today i changed my oil....switched oils about 12k ago to valvo blue 15w-40. Everything runs good. I went 6k on this run..I had to add about a quart at 3.5k...not to bad...about the usual. When I was pouring my old oil back in the jugs it only took about 2 gallons (8 quarts) just about to empty my drain pan. I understand the filter takes some. Oil gauge is in normal range. Oil level on the dipstick is in operating range. My truck doesnt have an oil leak, never has, I check my oil reguarly. Do diesels usually drink this much or is mine just special like that..?

 

[TARM]

That does not add up.

8 quart at most 2 for the filter but that leaves you 5 short.

If you were checking your oil there is no way all of a sudden you lost 5 quarts and did not see it. Certainly not with what you have described. No engine magically eats oil during a change yet shows fine on the dip stick before hand.


Our 7.3s and even the 6.0 have a 15 quart drain capacity with filter replacement.
Now there total capacity is closer to 17 but that is including oil we do not get out with a normal change that is in the oil rails and HPOP system.


15 is the number 2 for the filter at most. So we are at 13 from the pain if at the proper full level.

Do you normally change your own oil? If so is this the first time this has happened? What if anything did you do different? Different pan, different jugs etc..

Sure your drain pan did not leak spill or spill during change?

Are you sure those jugs are gallon jugs and not 5 quart jugs as some use 5 gallon jugs as that is the typcial amount for gassers as well as it is then 3 jugs for our engines as well..

Did you check your oil level right before you changed it? If not when was the last time you checked it? The operating range on the oil dip stick covers 2 quarts.

Given 1 quart at 3600 mile another quart would be reasonable but as long as when you filled you filled to the top at the full line that first time at 3600 you are still only looking at 1 quart.

When you change it did you add 15 quarts of oil to it?


Unless you have a major leak that just cropped up I very much doubt you were 5 quarts low. Not sure if your engine would even run at that level. Certainly not well.

Something is not adding up.

Either you did not get all the oil into your drain pan. it leaked, or the jugs are not 1 gallon. The only other explanation is that from the time you last checked your oil where you said it was never outside the operation range to when you changed it you lost:

Worst case:

15 quarts
minus 2 for fitler
at the bottom of the operating range so minus 2 quarts
11 quarts out the drain hole.

You are 3 quarts shy and that is the worst case at being at the bottom of the dip stick operating range. Given 1 quart at 3.6K I doubt you lost a full 2 quarts in that next 2.4K when you changed it at 6K.

FYI going forward I would never go past 5K with a dino oil or any of the lower end "synthetic" You can get away with a more on a good syn but you need to do a oil analyze to find where the good point is with a bit of saftey margin to cover harder use unless you plan to do regular UOA.

 

[Big Monk]

Yes I do change my own oil.

The jugs are standard 1 gallon (4 quarts)

I have not done anything different since I started changing it on my own.

I did not check it right before I drained it, just knew it was time for one.

Yes I spill some on the driveway out of the catch pan but not enough to make that big of a difference.

I check it the oil about every 1k...or every two or three weeks.

The only reason I went 6k on this run is because I didnt have the money at 5k to change it. Usually it gets changed before 5k.

 

[SyN]

Do all 7.3L hold 13qts + 2qts within the filter? To get to the full mark on my dipstick I need 14qts total. I wonder if all the dipsticks are made equal? If everyones holds 15qts? I best just start pouring in 15qts.

 

[TARM]

I can tell you that no not all dip sticks are the same. I have seen this personally. Not saying is a every day thing but I had a 302 and measure another friends and it was 1/4 dif from the top stop to the full line. In vehicles that do not have HEUI or hold oil its easier as you can drain basically all the oil and then add the correct measure amount then mark the dip stick. The next question then has to be how sure are you that the oil container your oil is coming in is actually filled with exactly the amount labeled? You would need to measure it off a know marked container.

When I said 2 quarts I said roughly. I have not taken the time to check it to a high level of accuracy. It likely can and does vary from filter to filter make model as well or at least could.

The general way I do OC

Warm up vechile

Drain for a long time usually rotate tires fuel filter etc while its up.

Fill filter with a good amount

Fill engine with what is remaining of 14 quarts.

Fire it up and let run for a couple mins

Cut off and wait a bit. Check oil

Add remaining oil to bring it exactly to full line on the dip stick.


I work out of 5 gal buckets so other than the first 14 quarts I am adding the last bit without specifically measuring that final amount but the times I did use quart or gallon containers I seem to recall very close to exactly 15 quarts with filter change on my dip stick. That is what the manuals all say. Unless you add something to effect its total volume such as bypass filters over or undersized filter, HPOP reservoir extension from Dieselsite etc...


IT would seem logical that if all these engines are very close to identical that with confirming the amount of oil you would want to do a complete basic oil filter drain. Add exactly 15 quarts of oil. Fire it up. All it to sit on flat ground. Then check and mark exactly the full line on the dip stick. Maybe others with join in with opinions.