Hi I am new here I judt bought a 2002 oldsmobile silhouette and when I am driving down the high way at about 75 mph the van is turning about 3000 rpm's . Is that how they run

 

At that speed it should be around 2000. Sounds like the overdrive may not be working.

 

So what would I need to change out to fix it

 

And thank you

 

You would have to get an overhaul of the transmission. At the very least get that gear and/or clutch replaced. How many miles? I have a 99 with 185,000 miles and original tranny with no work done other than fluid changes.