1994 st auto Shaking Options

[Noahwhite2014]

Basically when warm, and at a stop light occasionally the rpm drops to around 650-700, the steering wheel shakes and i can hear the interior plastic also shaking. I can see the hood shaking as well. Usually at stop lights it drops to around 800 rpm and there is no shake. It doesn't stall, it doesn't sound or feel like it will, it just vibrates the whole darn car.

Known issues:
All 4 engine/trans mounts have cracked rubber - anyone know where i can get a good set for a reasonable price? Being that i live in hawaii rubber that isn't indoors pretty much need replacement every few years... so i was also wondering if filling the entire area that was rubber (on the old mounts that i clean and remove everything thats not metal) with silicone rubber would be an option, it would allow a lot more movement though, just curious due to the fact that silicone rubber lasts a lot longer in my engine bay. I was looking at poly filling engine mounts around the center of the mount, then filling in a thinner layer around it with silicone to dampen the vibration, but not allow as much movement as just silicone rubber, and it won't be as harsh as just poly. But id still have to redo it all every 5 years or so, since the poly will still break down just like rubber...

But anyway
Ive replaced spark plugs and wires, air filter, oil and filter, the usual stuff. Cleaned the throttle body and EGR. What else would help smooth out the vibrations? A new fuel pump, new fuel filter, cleaning injectors, and the entire intake manifold/runners?

I wanted to clean the manifold, but had a hard time removing it.

What do you all think?

[Bitter]

replace the mounts and clean the throttle body and IAC off the car.

[Noahwhite2014]

Wow i thought i replied to this... oops

So anyway when replacing my radiator and trouble shooting overheating issues, I inspected my motor mounts further. My front mount i can literally see through part of it. The passenger side mount i can see cracks. The rear mount i can see a crack and gap starting to form. the transmission mount looks to be in the same condition as the passenger side.

will this set work for a 1994 st auto?
http://www.ebay.com/itm/Toyota-Corolla-93-...628&vxp=mtr

[The_enD]

You may consider poly bushes.

[Noahwhite2014]

You may consider poly bushes.

Do they go on in addition to motor mounts? Not too farmiliar with them but if they go on the outside I assume it would prolong the life of the rubber mounts while adding minimal vibration to the cabin

[The_enD]

They replace the rubber, they'll most likely outlive the car. Some people report vibrations, so you have to find quality poly bushes.
They also help the engine move less, thus giving you better response when you step on it.

[Noahwhite2014]

They replace the rubber, they'll most likely outlive the car. Some people report vibrations, so you have to find quality poly bushes.
They also help the engine move less, thus giving you better response when you step on it.

Okay sweet, wait so if they replace the rubber, I can just order those, and carve out the old rubber and put in the new bushings? If so, they sound like the way to go

[The_enD]

Usually sold on exchange basis, once you've receive them, you send the old ones.

[Noahwhite2014]

Mounts replaced. Vibration still very strong

Cleaned throttle body, intake manifold, iac, EGR
Still vibrating

Replaced fuel filter, washed my air filter, checked plugs and wires which are under 2000 miles. Car didn't shake like this 1000 miles ago,

I'm lost. I remember seeing a video saying that the driveshafts could cause vibrations in the car at idle? Idk how but I'm willing to replace them since my left side is bad anyway.

[Bitter]

Is the harmonic balancer broken/wobbling? Did you make sure the mounts are all centered correctly? You need to loosen them, shift the car back and forth a few times, then tighten them, otherwise the mounts can load against the engine and make the car shake bad.

[Noahwhite2014]

Is the harmonic balancer broken/wobbling? Did you make sure the mounts are all centered correctly? You need to loosen them, shift the car back and forth a few times, then tighten them, otherwise the mounts can load against the engine and make the car shake bad.

Dont think anything is wrong with my harmonic balancer, I'll try recenter the motor mounts. Do you mean the passenger side and the transmission mount though? Or all of them have to be perfectly centered? I had a hard enough time getting the rear one out lol

[Bitter]

Mostly the side mounts, the front and rear are just roll stoppers. The front mount though can transmit vibrations into the cabin but much less likely than the side mounts, I take it you used after market engine mounts? They're notorious to be made of the wrong hardness of rubber and shake as bad as worn OE mounts or worse.

[Noahwhite2014]

Yes anchor all around. Oem is far too expensive for how long they are estimated to last in my climate

Should I pick up oem or a different brand side mounts?

This post has been edited by Noahwhite2014: Mar 16, 2015 - 1:05 AM