Check engine light

If you are not way over due for an oil change, the only things that I can think of that would cause your oil to become black and like sludge is if a contaminate was deliberately put in the motor, you have coolant some how making its way into the motor, or your pcv valve or system is bad. You need to flush the motor as soon as possible to remove as much sludge as you can or it will not last too much longer. Sludge is an engines worst nightmare. I am a little confused as to how a service light would be on, but no codes are being given. Usually anytime a service light is on, it will always follow with a service code. Find your pcv valve and check if it is faulty by shaking it. If you hear a rattle, it is good and does not need to be replaced.

Change your oil on a regular basis within the recommended time in your vehicle’s owners manual. Keep in mind that this doesn’t mean you have to change it every 3000 miles; most automakers recommend 5000 – 7500 miles. When you regularly neglect these guidelines and exceed 10,000 miles, that’s when you can look for trouble. To supplement your oil changes, add Bell Engine Flush before you change your oil. This will remove oil sludge deposits in lubricating areas with your oil change. Sludge buildup is reduced and your lubricating system stays cleaner, longer