I have been tracing a vibration in idle for longer than I even care to admit. During warm up ( until operating temp ) it idles rough. After it warms up, it get better but still not where I know it should be. I know the 1ZZ isnt the smoothest by design but Heres my story.
-Replaced all engine/trans mounts twice and I will explain why: Early 2020 I replaced the front and side mounts myself. The rear mount ( firewall side ) looked to be too much to handle so I decided to have a mechanic take care of that one. COVID came in and I did not feel comfortale taking it to a shop...so for 9 months the car vibrated terribly and violenty. I found a mechanic that would come to my house so it will be safe repair pandemic wise. He replaced the rear mount and it was shot, completely torn. Practically driving with 3 mounts. After having that last mount replaced, I still had this vibration at idle. Being that I drove with a mix of new/old mounts....I suspected after 10,000 miles maybe I prematurely worn the new ones. So I did a little experiment: I replaced one mount at a time and see if the issue improved...and it did. As I replaced each mount, the vibration became less and less. So its looking good here right ? When I had the rear mount left and still just a bit of vibration, I thought that this last mount would finally do the trick. It did not change anything. So I guess I can rule out engine/trans mounts now LOL. The mounts are all Toyota OEM.
-I do have a PO 442. Replaced both gas caps, purge and vent evap solenoids had a mechanic do a smoke test. He couldnt find any leaks, he suspects the charcoal canister maybe leaking internally. In my opinion if the leak is that small, it wouldnt contribute to THAT rough an idle. I could be wrong though.
-Replaced all plugs in the last month, the coils are Denso units that are 2 years old from a missfire I had, so replaced all 4.
-Fan assembly. The other day I noticed when I had the key on/ignition off there was a vibration in the steering wheel. Weird because the engine isnt running. The fan was on high ( car was just driven and I was ready to start it again ) I did this a 2 more times and noticed the same issue. The fan seem to have excessive vibration on high speed. When the car was off I turned the fan blade by hand and just before it stopped i heard a small squeal. My logic...the bearings are worn, and putting a electrical load and causing a little vibration. New fan assembly and no change. I also noticed the vibration was more apparent when the AC condenser fan kicked in on high and that also led me to beleive the fan assembly may be causing my issue. That leads me to the next thing....IAC valve. Im also experiencing a hard start when the car has been sitting after it has been driven. It starts up fine in the morning.
-The IAC and throttle body was cleaned 3 years ago. Aprox. 25K miles ago. This was the 2nd time it has been cleaned. I cant see it being that dirty that it would cause rough idle. Even at the dirtiest it never idled this way. Unless the IAC is just faulty. I do have 272,000 miles now. With the AC on it does idle about 800 RPMS and the idle doesnt dip with a load from the AC. So its seems the IAC is working correctly. I understand that the IAC is supposed to bump up the RPMs when the AC condenser fan kicks in, but my RPMs are steady at 800 and not fluctuating. Again....I can be wrong, thats why I havent fixed it LOL.
Any ideas ? Im stumped. Im starting to think I did some kind of damage driving with a bad motor mount for so long.
* 2003 Vibe Auto Satellite Silver w / Moons & Tunes
* Kenwood Excelon KDC-X597
* Polk DB651-Speakers
* Soundproofcow Roadblock R sound deadening in all doors
* Drop In K & N Filter
* NGK Iridium IX Plugs
* 27 MPG City/Highway with AC on