Oil Check

[richierich]

Hi everybody,
Just a quick one.I'm getting different opinions on when you should check the engine oil for a correct reading.I thought when the engine is cold this will give you the correct reading, but a mechinac said best reading when its hot.

[Not_An_Abba_Fan]

The best time to check the oil is when it is cold and sitting for a while, preferably over night. The best time to change the oil is when it is hot.

[dufus]

When the engine is cold all of the oil has drained into the sump, so it is the best time to check the level.

[richierich]

Thanks guys ,i thought so. I've been doing that for years.

[commsirac]

Unless you are using oil with the viscosity of cold molasses, and check it within minutes of the motor being started from cold, the difference wont be of any significance.

[burnz]

Hi everybody,
Just a quick one.I'm getting different opinions on when you should check the engine oil for a correct reading.I thought when the engine is cold this will give you the correct reading, but a mechinac said best reading when its hot.

to me your mechanic is right.
your oil is in the gallery's.
your oil is at an expanded rate.
that way you know it hasent drained from the gallery's and contracted when cooled.
simply their is no right/wrong answer in this senario but it is easyer to change when hot.
sorry for the inconclusive answer but it's all the same.


burnz

[Not_An_Abba_Fan]

And how could you know that the amount of oil in the galleries equals that of the amount of expansion?

The difference between cold and warm checking isn't that much, but if you were to add oil up to the full line within a few minutes of switch off, you would over fill the oil. Every millimetre of oil on the dipstick on the ecotec is 50ml of oil in the sump.

Rule of thumb is to wait at least 10 minutes after switch off before checking the oil.

[burnz]

And how could you know that the amount of oil in the galleries equals that of the amount of expansion?

The difference between cold and warm checking isn't that much, but if you were to add oil up to the full line within a few minutes of switch off, you would over fill the oil. Every millimetre of oil on the dipstick on the ecotec is 50ml of oil in the sump.

Rule of thumb is to wait at least 10 minutes after switch off before checking the oil.

as you said wait 10 minutes i though that was self evedent.
but the difference between cold/hot 30*C/280*C is a big difference in expanion

[s1nge]

yeh when its cold, mechanic was trying to trick u probs.

[GOTMYN]

Funny this, but you have just serviced a car, you add the new oil...check dip stick, add a bit more, it was low.... then OK it looks right, you start the car.... let it run for a minute or so, then shut it down, again you check the oil, (you may have fitted a new filter), this will steal some oil from the first reading.... OK, needs a little more..........

What have you just done?? Checked engine oil after the car has been running!!

This is done after every service at every workshop I know of!!

[minux]

Funny this, but you have just serviced a car, you add the new oil...check dip stick, add a bit more, it was low.... then OK it looks right, you start the car.... let it run for a minute or so, then shut it down, again you check the oil, (you may have fitted a new filter), this will steal some oil from the first reading.... OK, needs a little more..........

What have you just done?? Checked engine oil after the car has been running!!

This is done after every service at every workshop I know of!!

It really makes no difference at all when you check it. Valvolines rep has said it is better after it is has been running for a few minutes(oil specialist). I always check it when its cold, then again when i am stopping, that way i take the difference in between.

[Not_An_Abba_Fan]

as you said wait 10 minutes i though that was self evedent.
but the difference between cold/hot 30*C/280*C is a big difference in expanion

Yes, but as I said, how would you know the two volumes would be the same?

[burnz]

Yes, but as I said, how would you know the two volumes would be the same?

if driven long enough you will read true oil as posted earlier
2nd water in oil boil's off

[bradcad]

In my previous cars (no need to worry any more) I made a mark on the dipstick where I knew it was reliably full when hot- after a minute or two after shutdown, usually when getting fuel. Expansion typically added about 2-3mm on the dipstick for older cars.

[Not_An_Abba_Fan]

if driven long enough you will read true oil as posted earlier
2nd water in oil boil's off

You still haven't really explained anything.

your oil is in the gallery's.
your oil is at an expanded rate.

How can you know the oil that is in your galleries is the same volume by which your hot oil has expanded?

that way you know it hasent drained from the gallery's and contracted when cooled.

The point of a dipstick and an oil level is to keep the required amount of oil in your sump to sufficiently lubricate the engine under all driving conditions. I know the VT service manual states that the oil must be at operating temperature but not checked for at least 10 minutes after shut down. Some vehicles require the oil to be cold. I always check it cold when I can, and even if it is hot, I will not add any if the mark is over half way between add and full.

[burnz]

sorry if vaige post 6 all the same.
cold, no oil in gallery
hot expanded oil is in gallery as well in sump (virtually the same)
bye volume.

[Not_An_Abba_Fan]

Thats my whole point though, how do you know it's the same? It could very well be, but for how long after you switch the engine off do the volumes match? A few mm either way doesn't really matter but there is always the danger of over filling.

[burnz]

Thats my whole point though, how do you know it's the same? It could very well be, but for how long after you switch the engine off do the volumes match? A few mm either way doesn't really matter but there is always the danger of over filling.

if you wish to complain about 2mm then so be it.
10 min is the norm as posted earlier.
(over filling will burn out the exhaust) asuming 1~2mm over fill
more than this look at seales