Ive had this problem and have seen a couple cases of the same thing that is happening to me. I went to a toyota dealer who basically said tough luck as this happens to many TCs.

Symptoms: (Im auto btw)
In park no vibrations or anything.
In Neutral barely any vibrations but with A/C on vibrations
In drive Vibrations, feels like im getting a back massage with the AC on.

Idles at about 700rpm~ and that just seems way too low, in idle if i give it gas and raise it to ~800 the idle goes away. Sometimes in drive when I'm at the red light it won't vibrate at all and then the fans will kick on and the vibrations come crazy.

Should I look to see if there is something wrong with my fans? Is there any type of aftermarket tuning anything that will allow me to raise my idle rpms? I'm not a big car guy so I don't really know all that much about this.

UPDATE:
I wonder if this is the source or a result of the shaking or not related at all...whatcha think?
[youtube]VCuzNoEvzWQ[/youtube]

I dont know how to embed.

 

Would a unichip help out there is one for sale cheap in my area? I only have exhaust but its programmed for i/h/e

 

the only time mine idles rough like that is when I'm getting near the oil change. Mine was really rough before this oil change I just did. I used some BG 109 to clean everything out and put in some new Royal Purple oil and Royal Purple filter. That improved the rough idle a lot. how far away are you from your oil change?

 

Just changed it. I saw a post where they said that happens around oil changes but it's constant for me. It's been going on for like 40k miles and it's getting old. I use royal purple synthetic. Forgot to add you can hear my timing chain now but everything goes away when i raise the rpm.

 

the ecu in our cars are very annoying. when you change anything on the engine at all (even exhaust) it idles like crap. mine idles great with stock exhaust, but even if i just change 1 frickin pipe, it idles rough. i idle fine now that im boosted cause i can make fuel corrections on my FIC at idle. but in your case im guessing its one of these possible things:

-Exhuast
-Primary 02 sensor
-Dirty MAF
-Dirty TB
-Fouled Plugs
-Bad VSV

These are the common things that result in bad idling with the TC. its a very common thing on here.

 

It idled the same with all stock parts
Cleaned the MAF
Cleaned the TB but was a girl about it and idle was okay for a day then turned bad.
replaced plugs

Ive been searching around, I have the same batter from 2006 and some people say that it will cause a low idle? Should I get my battery tested/replaced? Could the battery even be related to the problem

cant the unichip or other fic let me get it tuned to make the corrections needed for it to run right?

 

yes engine management will allow you to have better controll over your idle, but you would be just covering up a mechanical problem rather than fixing it. no management will fix a mechanical problem.

 

when you did all the maintence, did you reset the ecu? if not, that is probably why it idled good for a day then went back. the ecu will fight to get as close to the tune it already knows. reset the ecu by unplugging the neg side of your battery for 20 mins. plug it back in, start the car and let it IDLE for about 5 minutes. dont give it any gas. then drive it around conservatively for a little while to let it re-learn. i bet this will fix your issue

 

usually I unplug it for the time it takes to clean it/mod etc. plug it back in. I don't let it sit for 5 minutes and I drive it like i stole it, so I guess tonight i'll clean the TB, get my battery checked, leave the neg unhooked, and leave a little early for work.

 

mine idles around 700rpm also but the idle isnt too rough. most of the time its decently smooth, sometimes it will shake a little bit. It was really bad right before my 30k mile oil change but when all that was done it was back to normal (normal being what I stated above). I'd like to stop it too if I could.

 

me and you have the same exact problem, i just posted a thread about it not too long ago. only happens when fan is on. I tightend a few of my exhaust hangers and that helped a little but the vibration is still there. only when fan kicks on too...i dont remember this happening when my exhaust was stock though.

 

happened when Im 100% stock. I noticed the grommets that hold my radiator in place are worn and there is movement with my radiator. check those! cleaned my throttle body a little and it helped out but it's vibrating again

 

it might be a bad motor mount. tcs in general idle rough imo. every one ive been in seems to not be very ride friendly. thats all i can think of

and that click you get from the "timing chain" is actually just the VSV valve opening and closing. it makes a bit of a clicking noice, and gets louder if its on any sort of metal object that it can vibrate on...

just my .02

 

My solid front motor mount makes the car shutter a little when the AC is on. Im in the same boat, if I could just add 75 or 100 rpms to the stock idle, it would all go away. Problem is, I brake stock motor mounts

 

thanks for the info. A car bumped my in the parking lot a while ago just before all this started. I wander if somethings up with my motor mounts. I also wish I could just bump the rpms up and be done. If this weather wasnt so crappy id take my car to the shop to have them start checking it out.

 

I would have a pro at least take a look at it. You can speculate and guess, and maybe you'll find it, or take it in and know for sure.

 

pro's dont always have the correct answer, i rather diagnose it first and find the exact problem so that incase im not able to fix it myself (lack of tools or what not) then I will know exactly what to tell the pro to fix.

something in the motor of the tc is causing this vibration. could be a loose fan mount, when the fans kick on they create a small vibration that at the right level turns the car into a tuning fork ... well thats one of my theories so far

 

as thetruthtruth said I am looking for at least a general idea so I don't get worked when I go to a shop. I've been running different cleaners through the car. It seems like if I drive aggressive at all then it will shake, but if I cruise(literally drive like an old lady) than no vibrations. I might take it to the shop, let them know what I see and talk it over. The top piece to my fans looks like it's warped and maybe it's touching. My dad said that if something in the chassis is vibrating they have something called chassishear or something and they'll be able to pinpoint it. Also going to have a onceover of the car and see how everythings looking.

 

MrHat - I have the same problems on my 05 but MT. RPMS drop rather low especially with A/C on and I have all lights on and press the brakes. lol - I just live with it. It's not like the car is gonna stall out on me (yet.... ) . I just replaced the MAF sensor cuz i shorted it; cleaned TB, but about to do an oil change before winter's here.

OEM battery too. So I just live with it or rev it up a bit just to feed some gas and go!

 

updated the first post.