Question When do you add oil?

[Joe Hogan]

New to Cummins L9 450 diesel engines. At what point do you add to engine oil? 1 or 2 qrts down? How critical is being slightly low?
Typically I’d put a qrt in if down a qrt or slightly more. But with such a large sump it seems that being a qrt low would not be a big deal.
I carry a gallon jug in the RV.

 

[Neal]

Make sure you add the right oil, I can't remember which one I have. I have not seen oil levels drop AFTER I had both an oil pan gasket and head gasket replaced. Prior to that I was adding a few quarts a year. So hopefully you don't see a need to add oil or it may be a symptom of a problem. I'd say as it gets towards the bottom of the fill line add until its midway of the fill area. A quart at a time if using quarts, best guess from a gallon jug.

 

[Neal]

The question though is when to do your first oil change on a new engine? Then see if stabilizes after that.

 

[Kevin D Pem]

Keep it up!!! Oil is part of the cooling system!

 

[CaptainGizmo]

New to Cummins ISL 450 diesel engines. At what point do you add to engine oil? 1 or 2 qrts down? How critical is being slightly low?
Typically I’d put a qrt in if down a qrt or slightly more. But with such a large sump it seems that being a qrt low would not be a big deal.
I carry a gallon jug in the RV.

Joe,

In terms of "function"...the ISL carries so much oil that you don't have to worry until the level drops down beneath the "range" on the dipstick. With the design of the oil pan and pickup, there's no way for the oil pump to ever "starve" or "cavitate" with being even 2 quarts low. With a 7gal capacity, that would be about 10% worth.

On my ISX, with over 13gal, I don't worry until the oil gets down to the bottom of the range.

But, in terms of being super diligent, I think there's no reason to not keep it "topped off".

I think the common "question" for me, has always been just "how much" oil does that operating range reflect? Best I can guesstimate is 2-4 quarts...depending on our engines.

HTH

 

[Joe Hogan]

Cummins approved, this is what I use. Not sure that a 15w-40 is necessary for my usage.

 

[Neal]

I'm using Rotella Duralec, can't remember the specific type. May want to ask at the oil change what is being used.

 

[Kevin D Pem]

View attachment 21890Cummins approved, this is what I use. Not sure that a 15w-40 is necessary for my usage.

Sometimes, it's not about usage, but about components. Be sure what you use for oil weight, is in line with manufacturers spec for conditions vehicle is used.

 

[Neal]

If in doubt check Amazon. I have this, not Rotella:

Amazon product ASIN B00VAVZ904

 

[Kevin D Pem]

If in doubt check Amazon. I have this, not Rotella:

Amazon product ASIN B00VAVZ904

One of the best out there if you can afford it.