Check Oil when hot or cold?

94mx3precidia · Post by **94mx3precidia** » October 2nd, 2007, 6:51 pm

Ive heard people saying that you should check your oil when your car is warm but i have also heard people saying that you should check the oil when your car is stone cold, like first thing in the morning. Which one do you think is correct and why?

Post by **Mooneggs** » October 2nd, 2007, 7:16 pm

I usually check mine when the engine is cold. If you check it right after you have run it (hot) the oil will not all be in the oilpan and you will get an incorrect reading...

umcamara · Post by **umcamara** » October 2nd, 2007, 7:27 pm

Mooneggs wrote:I usually check mine when the engine is cold. If you check it right after you have run it (hot) the oil will not all be in the oilpan and you will get an incorrect reading...

Here here...

Tunes67 · Post by **Tunes67** » October 2nd, 2007, 7:38 pm

Checking it cold is the easiest way to get a accurate reading.. but.. if you shut the engine off on level ground and wait 15 minutes before checking the dipstick.. that should be more than suffcient time for the hot oil to run back down into the pan. Make sure you are on level ground at the time you check your oil level though.

Tunes67

94mx3precidia · Post by **94mx3precidia** » October 2nd, 2007, 7:43 pm

ya my driveway is pretty flat. When i check my oil level its always first thing in the morning before i started my car.

turbulence23 · Post by **turbulence23** » October 4th, 2007, 7:04 pm

a little bit hot or cold, doesnt really matter, just make sure you do it always at the same time, so not the one time when its down for 15 min, and the other time when its parked for a night...

just check it when its standing for a night or after cooling down for some time, not one week the first option and the second week the second one...

94mx3precidia · Post by **94mx3precidia** » October 4th, 2007, 7:10 pm

but i was thinking of this.....

if you check the oil when all the oil is in the oilpan and its at the full mark, when the engine is running the oil isnt actually full beacuse there will be some oil in thetop end of the engine.

I don't know, its hard to explain.

basically what im trying to say is that should i compensate for the amount of oil that will be up in the top end of the motor while its running so that the oilpan is full while the engine is running?

umcamara · Post by **umcamara** » October 4th, 2007, 7:21 pm

94mx3precidia wrote:but i was thinking of this.....

if you check the oil when all the oil is in the oilpan and its at the full mark, when the engine is running the oil isnt actually full beacuse there will be some oil in thetop end of the engine.

I don't know, its hard to explain.

basically what im trying to say is that should i compensate for the amount of oil that will be up in the top end of the motor while its running so that the oilpan is full while the engine is running?

No. The engineers, believe it or not, have planned for the occasions when your engine will be running.

The full mark on the dipstick corresponds to how much oil should settle in the oil pan, so that there will still be sufficient oil in the bottom end when it's running.

94mx3precidia · Post by **94mx3precidia** » October 4th, 2007, 7:22 pm

ok that makes sense, youd think that they would have to design it like that.

neutral · Post by **neutral** » October 4th, 2007, 7:49 pm

Plus you would risk an overfill otherwise and that can lead to a "washing machine effect" where at sustained rpms, like highway driving, the crankshaft whips the too-high oil level into a froth full of air bubbles = poor lubrication. Some Dodge engines are reportedly especially sensitive and owners report seized engines while running on the freeway with overfilled oil.

lakersfan1 · Post by **lakersfan1** » October 4th, 2007, 11:12 pm

You check motor oil cold, and automatic transmission fluid hot. Manual tranny fluid you can check either way.