Well it seems like the Tib has been doing this for the last month or so. I thought for some reason it was the tires because of bad alignment and uneven tires. Well all is fixed and the tib still runs kind of rough. I changed the oil, spark plugs, and air filter is okay. Note this is an A/T. The engine seems to get rough between 3-3200rpm and then smooths out as the revs climb. It sounds like its kind of a groan and makes enough vibrations to rattle the passenger door. I never noticed this till about 2months ago. I just didn't know if this was a common issue with the Tib being a 4cyl and all. I really don't think anything is catostrophically bad because the engine doesn't miss and the trans doesn't slip or anything of the sort between that rpm range. It runs fine, but it seems to to just run rough in that range. I did however notice that the idle is kind of shakey sometimes and never stays at one speed, but I may need to adjust the IAC. Thanks for any input.

 

maybe bad engine/tranny mount(s)

 

If you have an aftermarket exhaust check to make sure your not touching anywhere. Make sure the hangers are in the mounts and also you don't want to be touching or even being close to the rear axel.

 

everything is stock...and I couldn't see it being bad mounts because it only does it between 3000-3200rpm.

 

Mine does the same thing and my mounts are only like 5k miles old. Has done it as long as I can remember, with my old block and my new one. My idle is fine though.

 

I am telling you folks, something is vibrating once you hit that rpm range. I had the same thing twice.

First my cat was close to the chasis, and from the vibrating exhaust ( mine was roughly at around 2000 rpm ) it would vibrate and only at that rmp.

With my aftermarket exhaust I had the same thing, at around 2800 so I checked and my exhaust was near my rear axel and it was vibrating from that.