I just read the post from "SSE WANNABE" and my '97 SSE has the same problem. It is extremely annoying! Mine only does it at highway speeds when the motor is good and hot, it is more like a surging. I can see the tach going up and down (even with the cruise on) when it does it. It is kind of like being in a boat in the middle of lake Erie! I have not had any codes come up and have changed plugs and fuel filter. I will try changing the wires now that I read the other repsonses. I just haven't had the cahoonas to take it to a shop for fear of being raked over the coals $-wise! Any other information on this problem would be appreciated.

Bob
(sea-sick at 7o mph)

NO codes...sounds strange..I would have first considered Plugs/Wires etc..Strange there is no codes!!!! Does it fell like maybe Tranny surging?? Good Luck

I am not sure about the tranny surging. I guess can't tell. What would that feel like? I assumed it was something with the engine because the tach moves up and down as the thing "surges" down the highway. I did not have time to change wires over the weekend but it is on my list of things to try.

In o'drive, I doubt you would get an engine surge large enough to affect your tach to any great degree. The gearing of those puppies is such that there would have to be one helll of a mph change to make your tach change significantly.

My bet is that your transmission is either slipping or "hunting" from 3rd to o'drive and back. Probably the former though. Is your trans fluid up to level it is supposed to be at idle? What color is it? What does it smell like? Burned smell, etc.

Does your tach change + and - in response to assumed engine speed?

Give us more info.

try to knotice if your hood shakes at all

Well, tranny fluid is ok. Level is at top and it doesn't smell burnt or look bad. No apparent shaking of the hood. But, it was really doing it on my way to work this morning. At 60 mph tach is around 2200 rpm. Under load this morning the tach going up and down between 2200 to 2700 rpm. I can feel the car pull and let go in sync with the rpm fluctuations. The tranny will not shift out of OD though unless I punch it. When I punch the gas the thing picks up and runs great. As soon as it goes back into OD and I hit a hill or load the gas pedal a little ( like to accelerate slightly) the surging begins again. The only way to get it to quit is to let off the gas and subsequently slow down.

Thanks for all the reponses. Hopefully I will get this resolved.