Oil level difference in relation to its temperature

[stratosg]

I always check oil level when engine is dead cold. E.g after a whole night time passed. I cannot understand what a few and several minutes stands for. The same as normal operating temperature. No matter if is translated in English or in Greek.

[shyVRS245]

9 minutes ago, stratosg said:

I always check oil level when engine is dead cold. E.g after a whole night time passed. I cannot understand what a few and several minutes stands for. The same as normal operating temperature. No matter if is translated in English or in Greek.

AGREE TOTALLY.

[edbostan]

Since driving I have always checked mine cold. As long as it between the marks that is good enough for me, and the engine.

[Breezy_Pete]

For those that don't understand the reason this thread exists   or find the obsession with detailed level-observing odd, I may be able to shed some light.

 

A little while back there was a thread in which Nidza, and Offski had a fundamental disagreement about whether the oil level on the dipstick looks higher when the engine is stone cold, or when switched off for a few minutes from operating temperature. The two posts are in the middle of this page of this thread:

https://www.briskoda.net/forums/topic/457104-oil-level-way-over-max-after-service/?page=2

 

I threw In some curveballs about measuring the level with VCDS using the level sensor that most of our cars have, as an alternative, or addition to dipstick measuring.  I never really put enough time or effort into demonstrating agreement between what VCDS was telling me and what the dipstick was saying.  The dipstick on my car is one that's quite hard to read clearly.

On mine the differences are in the same direction as Nidza observes, but much less pronounced, only a very few millimeters between highest and lowest observed levels (with level sensor and dipstick agreeing reasonably well after a 'warm up' time for the level sensor of a few minutes when oil is cold; just the level sensor, ignition on but engine off).

 

That's why I was interested in Nidza measuring the relevant area of his dipstick  to see how those differences compared on his engine/car.  For some reason he won't do this, but never mind, maybe someone else has the same engine and could offer up a ruler to the area he has marked with green lines? Doesn't need to be any oil on it at the time.

 

I'm also still interested in what level changes Offski saw or measured in his saucepan when he tried an oil expansion/density experiment on his stove, but apparently he won't share that info, we must do the experiment ourselves. I asked until I was blue in the face on the other thread but only got fobbed off.

 

I should be able to find time over the Christmas break to do a better job on my experiments, but it would be useful if anyone else wanted to explore the behaviour of their engine's levels and level sensor too. More complex engines with turbos etc. may well differ a little from my simple one. 

 

 

 

[BoxerBoy]

A cold dip stick measure is your friend.

 

If there are no oil puddles under your car then everything else is “entertainment”.

[Gerrycan]

Google tells me that the volumetric expansion coefficient for unused engine oil is 0.0007 per degree Centigrade.

So a 100 degree increase in temperature will increase volume of a litre of oil by 70ml, or 280ml for 4 litres of oil.

Unless my maths is wrong?

 

 

Edited 3 December, 2018 by Gerrycan

[Breezy_Pete]

Looks correct to me Gerrycan. I believe Nidza linked to a similar calculation in the other thread.

 

[SuperbTWM]

Do you think its safe to microwave a pint of oil in a Pyrex jug?

 

Asking for a friend

[shyVRS245]

3 minutes ago, SuperbTWM said:

Do you think its safe to microwave a pint of oil in a Pyrex jug?

 

Asking for a friend

One way to get rid of a friend I suppose.

[Ootohere]

VW Group tell you or recommend to check the oil at Operating Temperature so not at 0*C or lower.

So they are saying see where 4 litres or 3.6 litres or 2.8 litres is on the dipstick at 90-100+ *C.

That means checking the volume of oil maybe 80*C hotter if it is at 10*oC in the cold engine.

 

Only check the 1.2 l 44kW engine with cold oil and it has a 2.8 litre oil capacity.

 

For Oil consumption tests the oil drained before a Test starts and after is weighed and not measured by volume so that they can tell or nearly tell the difference of oil lost.  They (VW) give the weight of a litre of engine oil as 856 grams @ 15*oC.

 

 

 

Edited 3 December, 2018 by Offski

[amwphotos]

Here's you all worrying about how much the oil expands, but have you thought about how much the sump, engine, oil filter housing expands when it gets hot?!

[Ootohere]

How hot is it actually getting, as hot as a deep fat fryer?

[Gerrycan]

30 minutes ago, amwphotos said:

Here's you all worrying about how much the oil expands, but have you thought about how much the sump, engine, oil filter housing expands when it gets hot?!

And the dipstick will be longer when it is hot too.    

[vRS-Daddy]

Hello oil aficionados, has anyone noticed oil consumption increase (need4top up more often) following a remap (Revo stage1) upgrade?

[shyVRS245]

7 minutes ago, vRS-Daddy said:

Hello oil aficionados, has anyone noticed oil consumption increase (need4top up more often) following a remap (Revo stage1) upgrade?

In my experience of remap stage 1 at 7,400 miles and stage 2 at 14,800 miles I check the dipstick every month from new and the EA888 engine has needed 0.25 litre top ups of Long Life Castrol Edge every 2,500 miles or so which only costs £3 per time so hardly breaking the bank. After 17,200 miles have put in 1.75 LITRES so far and first service indicated at 18,700 miles if this helps.

[Breezy_Pete]

6 hours ago, amwphotos said:

Here's you all worrying about how much the oil expands, but have you thought about how much the sump, engine, oil filter housing expands when it gets hot?!

 

Yes, mentioned on the other thread just after Nidza posted his calcs. Only sump expansion really relevant, I think. Will differ quite a bit between steel, Ali and plastic sumps, but still relatively small impact, I think (without having done any sums).

 

 

[Plantman]

Is it possible with VCDS to display the oil level on the MaxiDot?  It displays oil temperature after all.

That could be fairly useful.

 

I remember some French cars I've owned (I know, I know!!) displaying the oil level on ignition on. Not sure why more cars don't have this by default.

[YS53]

Because of where we live,our parking area is on a slope,so we have to check our oil levels with a hot engine,I usually get the engine up to normal running temp during a reasonably long drive.I then leave the engine to settle for 5 - 10 mins before I check the oil level.

The only car I have ever owned where there is a really big difference between Hot/Cold oil level check is on our VW Polo 1.4 16v AUB engine,if checked cold the level is always higher than if checked Hot,I have always assumed that there are a lot of oilways etc in this engine which gradually/slowly drain down into the sump overnight.When I do oil changes I always get the correct amount out during oil  drain so I know for sure  it is not getting overfilled by doing a Hot oil level check.

The only reason I know about the difference in oil level between Hot and Cold level checks is that before I retired - the Polo was always parked on the level.

[Breezy_Pete]

@YS53 do you use genuine oil filters? A filter that drains back more than it should might explain what you see?

 

[YS53]

15 minutes ago, Wino said:

@YS53 do you use genuine oil filters? A filter that drains back more than it should might explain what you see?

 

I had thought of that thanks Wino and it is possible,but my first oil level check after an oil/filter change will be with a hot engine,and it is usually ok because it is a measured amount of oil put in whilst topping up.

I usually use Manns,because they are usually a good price

I just standardised on one Filter Make because different filter manufacturers sometimes use a different size of 'Hex' on the filter body LOL.

 

cheers/rgds YS 

[Breezy_Pete]

Just running my BBY-engined Polo up to temperature on the (level) spot for a cold/hot comparison. It's almost exactly the same base engine as an AUA/AUB.

Edited 4 December, 2018 by Wino

[YS53]

4 minutes ago, Wino said:

Just running my BBY-engined Polo up to temperature on the (level) spot for a cold/hot comparison. It's almost exactly the same base engine as an AUA/AUB.

I say - that is above and beyond the call of duty young man 

[Breezy_Pete]

Got a photo sequence with a cold one at midday, then one as quick as I could after shutdown from op temp, then roughly every two minutes for the next twenty minutes.

The photos are a bit crap, but good enough I hope. Just got to try to stitch them together side by side. (And pop out again with a ruler to take a shot with that alongside the dipstick ).

[Plantman]

Mine is fairly consistent it seems.

 

At stone cold VCDS read 74.856 mm and on the dipstick from first wipe this was nearly to the top of the hashed pattern. Level is OK in my book.

 

During engine running the level seemed to drop to 59.656 mm on VCDS. To be expected, its being thrown around the engine.

 

Then after being used a bit (not fully hot sadly) and rested for a good 15 minutes the level was back up at 73.816 mm and on the dipstick, this was again near the max. Oil settled but still warm.

 

 

 

 

Edited 4 December, 2018 by Plantman
Typo

[Breezy_Pete]

Top work, shame you didn't take data points at 1, 5 and 10 minutes  after switch off though, could I encourage you to do some more? When you see my embarrassingly poor photos shortly, I hope you'll see that (my) peak levels are seen on the dipstick between 2 and 8 minutes after shutdown, several millimetres higher than cold.