I drove the bonnie some more today and found out mine car only does it with the AC on. Last summer my compressor started making some noise and I put some AC oil in the system and the noise stopped, but could the compressor be going out and stressing out the engine?

I have a 1995 Bonneville SE. I had the same problem around 45 to 60 MPH on uphill grades. I replaced the plug wires with Bosch but had a little shutter in it. I finnally broke down and replaced all the coil pacs this fixed my problem and I have'nt had any shutter at all since I did this.

These are almost always an ignition problem of some type,... distibutor/coil packs, wires, plugs. Feels like a tranny, but only occassionally is.

I thougt it was the tranny then I got a new one put in because I blew it up. and it wasn't that. And the chances of getting another trany that would make a car do that is slim. I thought it might be the coils. I already have new plugs and wires.

Yeah I would say just to replace the coil packs that would be anyone'* best bet in a situation like this if it still shutters after you replace the plug wires.

What and how do you replace the coli packs? how much are they?

All you have to do is take off the bolt on each of the three coils. remembering which plug wire goes where. do one at a time. There should be only one bolt on each coil. the bolts will be on the left side of the coil. And the price for each coil is $27.59 through www.gmpartsdirect.com. It is only about a 10 -15 minute job. Its real easy

I gave pretty close to $31 a piece at auto zone when I replaced mine.

I just changed my coil and my fuel filter and the shutter is completly gone. I payed about 30 for my coil. Oh yeah. I only changed one coil. So you should all check each of your coils seperately. It may only be one coil that needs replaced. Save your self $60

My car had the same hesitation . I had a tune-up done (wires, plugs, fuel filter and pcv) and the hesitation is gone. My mechanic said one of the wires was in poor condition.