10 Cobolt transnition acts like brake in lower gears.
New to this so if this is the wrong place to ask please direct me where to post.
10 Cobalt auto transmission acts like brake in lower gear and hard shifts at 4000RPM but frees up in high gear but at 65mpy runs 1200 more rpm(3500) than normal. This happened on a 400 mile trip but when I stopped at a truck stop to check fluid level. Car idled for about ten minutes while I looked for dipstick and found in book you can't check it. I decided to try to get it hame (70 more miles) but it started working correctly when I drove off. Has anyone experienced this? What can be cause?