Hello, Have a 2007 Express Van. I got a warning light on the dash the other day. Van has 18k miles on the 4.8l V8. The light appears in the upper left of the cluster. Yellow in color. Oil fill can with open end wrench. Do not have an owners manual. Bought the van used and it did not come with it. If I did get one were is it stored? I was thinking oil level or time for an oil change. Any help would be appreciated. Thanks.