Hi, so im going to change the oil in my 2004 e46 330Ci in the morning and im going to use Castrol Edge FST fully synthetic 0w-30 as recommended on the castrol website. The old oil is horrible, very blackand thick!! (when I checked the dipstick) so I was going to flush it out with some cheaper oil first and I already have some cheap 20W-50.
So I have 2 questions...
1. Will it be ok to drain the old oil (when hot) then run the engine with 20w- 50 till the oil is hot then drain it before filling with the Castrol oil?
2. Is it ok to use an engine flush? And if so should I use the engine flush with the old existing oil or the 20w-50? (I know its a touchy subject)
Would be nice to hear peoples views. Thanks