Content Wrapper

[Martin F]

Quote: Originally Posted by SiBradbury (original)

PS can it really be agreed that oil expands when it warms?

I am sure oil does expand as temperature rises. But so will the engine and sump so whether the level on the dipstick rises will depend on the difference between the coefficients of linear expansion of the various materials involved.

I would doubt that it makes much difference.

I suspect the requirement to check levels after the engine has been run and is warm is so that there is oil in oil pump, galleries, the cam followers etc. If it has been standing the amount of oil drained back into the sump will presumably be affected by how long since the engine was run which might be many hours and so may vary.