Oil testing for cars (free test offered)

[SilentDeath]

last few days I have been working on my oil change. I took it to a garage to get the sump plug out, but the mechanic wasnt there.. so they didnt want to do it after much trying.. so I got the CV boot done instead.

We changed the oil via the oil level float switch hole, I used my 15w40 cheap mineral stuff after using a flushing fluid. We did change the filter, and the car was tilted such that 90% of the old oil was removed. We poured in extra untill it ran clear before filling.

So I still had to get the plug out and put the proper oil in. I ended up taking it back, paying £10 for an hours use of the ramp and grinding the bolt off

But the oil, after just 24hours or so in the sump, had turned compleatly black... less than 20 miles...

Is that bad?

New oil is in.. GM 5w30 fully synthetic.

[dkmech]

Is it a petrol or a diesel? I forget. I guess petrol with a 5w30. It's hard to say without testing it. It could be that by running a flushing oil you have loosened some of the grime that settles at the bottom of the sump. This would then mix with your new oil and make it dirty.