oil sump washer - which way

[dxtans]

Hello,
Changing my engine oil in the next few days, hit a small issue..
For the compressed oil sump washer, which way should it go on the sump bolt ?

widest part facing down
or
widest part facing up

I've forgot, I know either the inner or outer part are two different metal strengths, but forgot which way.

Thanks
DT

[Juvecu]

Don't re-use a crush washer. If it's a new one the flat part goes towards the engine and the slanted/rounded part towards the bolt head. If you get it the wrong way around it can force the drain hole to the point of breaking pieces out of it. You can also just use a flat copper washer as replacement, these are normally re-usable many times, I just flip it each time I re-use mine.

Edit: This picture shows what can happen if you get it wrong.



Edit 2: This pic shows the right way around for the washer. In this case it's a rounded crush part, note the flat side will press against the engine casing when the drain plug is screwed in.

[dxtans]

Thanks for the response,  and thanks for the pics, to see what happens if you get it wrong

thanks
DT