someone changed my neighbors broken timing belt and the car runs bad. my question is would a broken timing belt cause internal engine damage it a 98 chrysler sebring lxi with a 2.5 v6.
Yes. There are probably a bunch of bent valves. A compression test of all cylinders will tell. Zero compression = bent valves. I just did this job and pulling the heads isn't that difficult. You may only have one damaged head, like me.