95 GP O/D engine rev.. help!?

I have a 95 Grand Prix SE. It runs like a dream on city driving (up to fourth). Once I hit O/D the engine seems to slip back and forth from fourth to O/D. This is usually for any driving over 55mph. What's causing this fluctuation?

I took it to a transmission place and they couldn't find anything wrong.

I know it can't be good on the motor and transmission.. Can any of you guys tell me what I can do before breaking down and taking it to the mechanic or what the problem may be? Thanks ;)

I have a 95 Grand Prix SE. It runs like a dream on city driving (up to fourth). Once I hit O/D the engine seems to slip back and forth from fourth to O/D. This is usually for any driving over 55mph. What's causing this fluctuation?

I took it to a transmission place and they couldn't find anything wrong.

I know it can't be good on the motor and transmission.. Can any of you guys tell me what I can do before breaking down and taking it to the mechanic or what the problem may be? Thanks ;)


I'd PM GTPDad or Big-L on that one. Those two are the only ones old enough to have ever had a 95 GP.
But welcome to the site. Nice to see people from Michigan out here.

Jim

hey i have a 95 GP and mine did the same thing a few times but it hasnt done it for quite a while im not sure but when it did it i changed the tranny fluid and since then it hasnt done it

did you use a better grade tranny fluid than recommended by GM?

yes i did i used proformance fluid