Black Oil

loughborough · Post by **loughborough** » Thu Oct 26, 2006 10:55 am

I recently did the first Oil Change since owning our Bongo,I dont know how many miles since last changed but I was shocked at the colour of it I have never seen Oil that black in a car before,can anybody tell me if this is normal please.

ChrisEm · Post by **ChrisEm** » Thu Oct 26, 2006 11:06 am

Er Yes. Oil carbonises and collects carbon from the normal combustion cycle. This will appear pretty horrendous if the oil hasn't been changed in a while, however oil turns black pretty much as soon you change it so don't worry it's normal.

tigger · Post by **tigger** » Thu Oct 26, 2006 11:50 am

ChrisEm's right. Colin Meldrew, our local oil nerd, will also tell you that diesel engine oil goes black sooner than petrol engine oil. Can't remember why....... Don't worry though - just change it reasonably often!

ChrisEm · Post by **ChrisEm** » Thu Oct 26, 2006 12:12 pm

Diesel oil usually has a high carbon content due to the combustion cycle which causes carbonisation of the oil, when I was on sleek grey war canoes we had centrifugal filters which used to spin the solids onto a filter paper liner, used to get inch thick deposits which set like cement left on the paper.