05blkbeauty

Just bought a 2005 c-6 and previous owner had changed oil aprox 3500 miles previously- I pulled dipstick and it was full- but oil was darker than I thought it should be (kind of a dark honey brown), so I changed the oil myself with Mobile 1 and noticed that afterjust a few hundred miles it is also turning darker (light honey color). The car has aprox 30,000 miles on it- is this normal for Mobile 1 or do I have engine problems?

RicK T

It's fine. Engine oil never stays "pretty" very long. Just follow the Oil Life Monitor, it is proven effective. Just for info here's talon90's explanation of the monitor:

http://forums.corvetteforum.com/1566265077-post14.html

LS1LT1

I never get too concerned about the color of oil after it's been run through the motor, though I do know of a few people that do get in a bit of a twist about it and I'm not exactly sure why LOL.
Oil often has detergents in it, those detergents can somewhat clean the inside of one's engine causing it to turn darker.

NYC6

Mobil, not Mobile. Cant believe how many people add an e.

Mobil 1 doing its job, no worries.

05blkbeauty

Thanks for the info, everyone- I'll try and watch the spelling! This is my first 'Vette- I think I'm hooked!

Joe_G

Do you by chance have the factory PCV system disconnected, with a open air breather installed, like the picture below?

I found that when I had such a system my oil got black really quickly. The factory system pulls a vacuum on the crankcase which draws combustion byproducts in and burns them. Without that vacuum contaminants stay in the crankcase.

I changed back to a regular catch can system pulling a vacuum on the crankcase and my oil stays pretty much clean between changes.

AU N EGL

Change the oil then.

it only takes 500 miles or so for the oil to change color.