Excessive vibration at idle, with new motor mounts.

[zdigg]

I have recently installed new motor mounts, seemed to correct my vibration issue for a couple of days, recently after a short trip at highway speeds the vibration returned,

I have no engine codes other than an ongoing p0705(neutral sensor issue).

I should note that I have recently installed a new header after discovering and crack in the old header.

I don't know what could be the issue, the engine started clunking on first and second with the old mounts, that issue has not returned with the new mounts.

The idle vibration is the worst it has ever been and I am tempted to take it to a mechanic.... I don't want to do that. I have pride. Please help.

 

[rj1784]

Did you install factory mounts or aftermarket stiffer mounts?

 

[hornsfan10609]

The cheap aftermarket mounts are made of a lesser quality rubber than OEM and will transfer more vibes through the cabin like an aftermarket solid mount. They will break in some and get better but aftermarket replacement mounts are never as smooth as OEM.

First I would check to make sure all your hardware on the mounts is tight.

 

[Inside]

Which brand of mounts did you use?

 

[pcb]

The idle vibration is the worst it has ever been and I am tempted to take it to a mechanic....

Seafoam ???

Whenever my car starts to shake at idle , I know it's Seafoam time,... (you've obviously got other issues too but Seafoam can't hurt)

http://seafoamsales.com/

 

[zdigg]

They are aftermarket Berneckly(sp?) mounts, The car had one solid Poly race style mount on the lower front mount that I put back to stock. As for seafoam, you have actually already recommended that to me and I did that back in november, pcb. It helped a lot then but I don't know if it will help now.

one thing I noticed today was that if I reset the car and force it out of limp mode the vibrations are much less severe and if(while in limp mode) I open the throttle to get the motor at 900rpm or higher the vibration totally goes away. I feel this may be engine related.

Something to note, my ecu idles at 700 on the dot when not in limp mode. in limp mode it idles at 652-690 bouncing up and down.... Could limp mode just be absolutely retarded? It's sorta annoying that the car would even go into limp mode over a clutch sensor, especially when it obviously has redundant systems to verify clutch depression(which I know it does) the car will raise its idle with the clutch depressed in both modes. Maybe its time to actually rewire my stupid clutch sensor.

to avoid confusion when I say limp mode I am referring to CEL throwing code p0705(the bane of my existance.)

 

[Hank3]

The Beck Arnsley mounts will transmit more vibrations into the cabin at idle. I had them for a couple weeks and eventually went with OEM. It was about $25 more but worth. This was just the mount behind the radiator.

 

[pcb]

As for seafoam, you have actually already recommended that to me and I did that back in november, pcb. It helped a lot then but I don't know if it will help now.

I say do it again anyway,... 10 bucks, ten minutes,...

...one thing I noticed today was that if I reset the car and force it out of limp mode the vibrations are much less severe.

If you do a battery disconnect reset, the ECU needs to relearn the car,... It's gonna run like crap for about 100 miles regardless,...

Could limp mode just be absolutely retarded?

Apparently the ECU dumps tons of extra fuel into the engine in an effort to protect it while the ECU is having trouble controlling it.

It's sorta annoying that the car would even go into limp mode over a clutch sensor,... CEL throwing code p0705(the bane of my existance.)

That's not the clutch sensor,... it's the neutral sensor on the transmission,... it's a really simple circuit and probably needs a new switch and/or a re-wiring, (really easy).

Check for continuity at the switch and along the wire.