I drove my daughter’s Dodge Neon last night and found that when I’m on the highway, the RPM goes up slightly every few seconds. I had about 30 minutes of driving until I was home so I tried to figure out if my speed had anything to do with it. It doesn’t happen when I decelerate or am at an idle. When I’m on a flat stretch of highway and using the gas pedal, the RPMs will increase. I didn’t notice the feel of the engine changing, I heard the engine speeding up a bit.
What kind of problem is this? I’d like to have an idea of the cost of repair before I take it to a garage. The car has 109,000 miles on it. Thanks!