17 hours ago, Rooted said:

@Seasider

It actually sits higher on the dipstick cold and all back in the sump.

 

I would have thought not as usually heat causes expansion, water being the exception of course.

 

As to thinning, the temperature we are talking here is 90 *oC or so, 'normal operating temp'.

 

I said "Presumably the oil thins as it warms up", i.e. describing a process not a state at a point of time. 

 

Just get the big soup pot out, put in 4 litres of engine oil, mark the level, heat to 90*oc and see how much the level rises, or actually does not. 

 

PS.

You have a car, dip the oil when cold. 

Do maybe 10 miles and stop, wait 4 or 5 minutes and dip it.  Remembering to wipe the cloth, see where the oil is.

Nothing difficult there, if in the same place or different then post which way, up or down.

 

This is for 'Mericans'  in the UK one the gal never mentions the engine / oil being hot. 

(There is one from NZ for Skoda where the check is shown being done with the engine running..)

 

 

 

 

 

@SeasiderYou think right. Heat can cause expansion. 

 Water expands about 4% when heated from room temperature to boiling point i read.  Lets assume the room temp is 18*oC..

 

If you can not find a table showing just how much someone else will.

 

But if it is 4 litres of Engine Oil rising from 5*oC to 90*oC, then how much does the level rise? 

 

Oil guy says about 4% more volume per 100*o F you heat the oil.  

Edited 11 January, 20242 yr by Rooted

25 minutes ago, Rooted said:

@SeasiderYou think right. Heat can cause expansion. 

 Water expands about 4% when heated from room temperature to boiling point i read.  Lets assume the room temp is 18*oC..

 

If you can not find a table showing just how much someone else will.

 

But if it is 4 litres of Engine Oil rising from 5*oC to 90*oC, then how much does the level rise? 

 

Oil guy says about 4% more volume per 100*o F you heat the oil.  

 

If you are going into this level of detail, don't forget that the metal the engine is made from ecpands as well, so the voids that the oil sits in will expand at the same time the oil expads. Anyones guess as to which would be the most and it is really trivial. As for the poiition of the oil filter, once a new filter is fillted and full of oil, that oil will noty drain back into the sump.

Capillary action'.

 

?

Did anyone bother today to dip their engine oil this morning, pre starting it, or maybe now, then dip again after a run and the engine up to operating temperature, stopped on the flat and after a few minutes?

Even after running it for 3 minutes from starting from cold try the dipstick and see where the oil is.

 

Were is it now, then where is it after it is up to 92*oC or so?

Edited 11 January, 20242 yr by Rooted