I have a 1998 oldsmobile intrigue replaced starter but after starting its slow releaseing

The most common cause of a starter that does not release correctly is a lost or misplaced starter shim. If you did the work look around the shop carefully and see if you can't find it and put it back in. If someone else did the work see if they can't find it and replace it. Despite what you may have heard these shims are vital and must be replaced when changing starters. If it is gone forever you can buy one from a junkyard. The shim must be from the same year and model and engine. A remote possibility is that the shaft the starter bendix runs on is rusty or dirty. It must be clean and lightly lubricated to work right. You must do something because the bearings in the starter will not stand being spun at engine speeds for long. Good Luck.

You likely need to add a starter shim or maybe two.The replacement starters are made from the cheaper 5mt style starters and depending on where they where manufactured,you may or may not need the shims.Any auto parts store should have them,you don't need to take the starter back off to shim it,just take out the furthest bolt from the block and loosen the other one and then you can insert the shim.Try one at first,then the second if that made little difference.