Correct way to check the oil level in a truck???

Yep check when the engine has been off for at least 5 minutes. when sitting all night the level will go up because almost every drop of oil drains back down to the pan. so in the a.m. it is probably reading 1/2 quart to much. not enough to cause any problems. I wouldn`t worry about it!

Check oil when the engine is cold.

Your engine needs oil when running. You want it full when warm, after running. Why? If the level is too high, the crank and rods will foam the oil, and foam does not provide good lubrication. If it too low, well you can figure that out for yourselves. Granted, there is a allowable level change, but it is better to operate on the upper end, than the lower end. Sudden movements of the vehicle can cause the oil to flow away from the pickup. Remember, when oil is up in the engine, it is not available for being fed to the rotating assemblies. If it is at the full mark, or just below, it is better than being at the ADD mark when cold. Remember back in the 70s and 80s when the ski boat era was all the rage. I can't remember how many engines came into the shop, under warranty, that were completely turned to junk. This was caused the operator weaving back and force at high speeds. The only real fix was a dry sump oiling system.

Oil should be checked allowing time for it to drain back into the crankcase. My preference is check it first thing in the morning when I check tires. On some engines, especially with a long dipstick tube, you will get a better reading if you remove the stick, wipe it dry, and wait a few minutes to re-insert. I pull the dipstick, check the tires, and then check the oil.

Logically, the reason a dipstick has a low (or add) mark and a full mark is to define absolute minimum and maximum levels. Also, there is really no significant change in oil volume due to temperature variations. Mine reads the same level regardless of ambient or engine temperature.

Since I do my own oil changes, I let it drain for an hour or so (from a fully warmed up state). Oil is still dripping after about 20-30 minutes, which is indicative that some is still working its way through the block back to the pan.

I would assume most vehicle dip sticks are set up to check the oil with the engine hot and after having just been shut off perhaps when stopping for fuel.

In fact my manual specified a range of temperatures at which they want me to check the oil. Basically normal operating temperatures - not after just having pulled a steep mountain grade with the oil really hot and expanded to the max.

I seem to remember that one of the big problems with over filling a crankcase is that the crankshaft can possibly start "slapping" down into it to cause foaming. And then maybe the oil pump pickup screen will start sucking foam instead of good solid oil.

But I'm not a gear head, so maybe that' an "old wives tale" or something.

Maybe we should all check the oil hot one day and then the next morning when cold and notice what the difference in level is. Just how much oil drains down into the pan overnight? And how much does it "shrink" when cold?

I am from the old school.
Always check oil when cold. If hot let it set for about 20 min.
To let all the oil drain down.

If you pulled the dipstick and checked it without first wiping it of the level will read high the oil traveled up the dipstick. If it was high after being wiped off then it may be over filled most manuals say after the engine has been run you need to let it sit for a period of time before checking my 6.0 diesel recommends 20 min.

joelyn wrote:
had my oil changed in my 2012 ram truck 1500. the truck takes 7 qts..
in the morning when i checked the oil the day after the level was about 3/4 of a inch above the cross hairs (full level) on the stick. I thought it was to high so i took it back to the oil change place and they checked it after it was running for awhile and the level was exactly at the top of the cross hair (full level).

So my question is> when should the oil level be at the top of the cross hairs, (full level) when the truck has been sitting all night or is the proper reading when the truck has been running for awhile?

just don't want to much extra oil in it so no gaskets or anything blows.
thanks

It should be in your vehicle owners manual!