I am a little confused about checking my engine oil level. The manual says to check the oil warm, after the truck has been turned off for at least five minutes. I check my oil after I fuel my truck which is approximately five minutes after I have shut it off. When I do this, the level on the dipstick always reads very low. Today it was right on the "add" mark. If I park it in my garage and let it sit for about 20 to 30 minutes, the oil level will show right in the middle (between full and add) or a little toward full.

I change my own oil and I put exactly 10 quarts in the last time I changed it. There is no evidence of any leaking or burning. I had a Cummins before this truck and the Cummins manual recomended that the oil be checked cold, like in the morning after the truck had been parked all night.

I'm just wondering if I should add some oil or not. Given the reading I get when I check it after fuelling, I am about a quart low. But if I go by the reading I get after the truck has been shut off for about a half hour, adding a quart would make it over full. I don't want to run it with too much or not enough oil.

What do you guys think, am I low or OK? Why the big difference in the oil level? Is it just not draining into the pan in five minutes?

Thanks in advance for any advice/suggestions.

Justin

I always figure it takes awhile for all the oil to drain down? I'd go by the morning check.

definatly let it sit for a while before you check. also make sure your on level ground and you are pushing the dip stick all the way down

Yep, go by the cold reading.

Just do like you did with your cummins.

it fooled me that way as well...

As long as it's there when its in your garage like you say it has plenty of oil... it just hasnt been gravity fed all the way through the engine just yet...

I guess I'll have to disagree with some of the posts. I'd check it after just a few minutes, like the manual says. Use that method and add/subtract accordingly.

Here's why. The oil level is most important with the engine running at regular temps, not cold when all the oil has drained down for an extended period of time. I'm not sure how much oil is actually in the circulatory path while running, but let's guess it to be a couple of quarts. When warmed up, after you shut it down, there is still some oil in the circulatory path, especially in the bearings and around the rockers; maybe up to a quart or so? One quart out of 10 is of course 10%. That means that your reading could be off by 10% using the cold method.

The most important thing regarding oil level is to assure the oil pick up is fully covered with oil at all extremes while in operation; fast starts, quick stops, operation on hills and slopes all make the oil level change in the oil pan realative to the pick up. If the pick up rides above the oil level even for a moment, oil pressure is lost and cavitation begins. I'm sure to some degree the oil level is compensated for this by design; there certainly isn't 10 quarts of oil in circulation at any given time. Anyway, I believe the reason they want you to check the oil after only a few minutes is to get the level set for use during operation, not stone cold after it's all drained down to the pan. You're going to get a reading that falsely sets the upper limit when cold.

With all this in mind, I must confess that the oil level is set high by design so that in daily operation, this probably doesn't matter much. Plus, it's possible that there are internal baffles in the pan, which assist in level control at extreme operation angles; anyone know if the D-max has baffles?

If a Cummins is designed to be checked with the engine stone cold, that means to me that the engineers have taken into account the drainback quantity and set the dipstick accordingly. The D-max manual says check after a couple of minutes, so that's the way the engineers designed the dipstick to read.

Just my .02 dollars of opinion.

I check next morning (cold) after oil change and use that level on the stick as a reference for future cold checks.

I guess I'll have to disagree with some of the posts. I'd check it after just a few minutes, like the manual says. Use that method and add/subtract accordingly.

Here's why. The oil level is most important with the engine running at regular temps, not cold when all the oil has drained down for an extended period of time. I'm not sure how much oil is actually in the circulatory path while running, but let's guess it to be a couple of quarts. When warmed up, after you shut it down, there is still some oil in the circulatory path, especially in the bearings and around the rockers; maybe up to a quart or so? One quart out of 10 is of course 10%. That means that your reading could be off by 10% using the cold method.

The most important thing regarding oil level is to assure the oil pick up is fully covered with oil at all extremes while in operation; fast starts, quick stops, operation on hills and slopes all make the oil level change in the oil pan realative to the pick up. If the pick up rides above the oil level even for a moment, oil pressure is lost and cavitation begins. I'm sure to some degree the oil level is compensated for this by design; there certainly isn't 10 quarts of oil in circulation at any given time. Anyway, I believe the reason they want you to check the oil after only a few minutes is to get the level set for use during operation, not stone cold after it's all drained down to the pan. You're going to get a reading that falsely sets the upper limit when cold.

With all this in mind, I must confess that the oil level is set high by design so that in daily operation, this probably doesn't matter much. Plus, it's possible that there are internal baffles in the pan, which assist in level control at extreme operation angles; anyone know if the D-max has baffles?

If a Cummins is designed to be checked with the engine stone cold, that means to me that the engineers have taken into account the drainback quantity and set the dipstick accordingly. The D-max manual says check after a couple of minutes, so that's the way the engineers designed the dipstick to read.

Just my .02 dollars of opinion.

Makes a lot of sense to me. Also the Cummins has more oil capacity so it's not as bad to check cold.

I usually let mine sit overnight before I check it, otherwise it reads low, even right after an oil change.

There is one thing you forget, cold oil is a little thicher and hot oil thins out. So, when you shut your hot engine off oil will fall to the pan in minutes. Do a test, put a vent hole in your bottle, pour the oil out of the bottle and see how it drains, then heat up the same oil to running temp. Put this oil in the same bottle and pour it out bet you it comes out in a fast hurry.
Me, I check my oil when I am filling up.