ive recently replaced my motor mounts... the two front uppers. and now the car tends to have a rough idle. and from time to time.. the rpms drop below 300 and stalls out... car was idling fine with the stock mounts but ever since the install of the new mounts... the car has been idling like crap. Is that normal? what are your thoughts.

 

anyone?

 

sorry, but use common sense on this.........how can mounts cause a rough idle? mounts have nothing to do with idle quality, what they do have to do with is vibration if using solid or poly mounts. Idle has to do with the how an engine is maintained and if all sensors and mechanical parts are in working order.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rsbad454 &raquo;</TD></TR><TR><TD CLASS="quote">sorry, but use common sense on this.........how can mounts cause a rough idle? mounts have nothing to do with idle quality, what they do have to do with is vibration if using solid or poly mounts. Idle has to do with the how an engine is maintained and if all sensors and mechanical parts are in working order. </TD></TR></TABLE>

Agreed, seems like a bigger problem. Have you checked your spark plugs (something with your fuel mapping might be causing you to run lean, atleast give you abetter idea of what the problem could be), or go ahead and take it to someone.

 

you're mistaking the vibration of the car with the engines idling. when i put new aftermarket mounts on my car the car seemed to vibrate alot more due to the fact that the mounts are alot stiffer now. the new mounts may make it seem to you that the engine is idling rough, it's just an illusion.

 

car idles perfect before the mounts were installed. after the install and driving around for a few hours/miles, the rpms drops.. rises then car stalls in neutral. my question is. has this happened to anyone else

and no i am not mistaking the vibration as a rough idle. by looking at my rpms via the vafc. it fluctuates up and down. with that said anyone have any answers?

 

Try putting the stock mounts back on. It will answer your question for you.

 

Maybe a vacuum line got inadvertently disconnected or punctured.

 

What he said...it sounds like maybe something got knocked loose when the new mounts were installed. Either a vacuum hose or wire.

 

what engine?

 

I have a Mitsubishi Lancer 2002. 1.8ltr wagon.
same thing happened to me. Changed the front engine mount....sameeeee thing.
car was idling rough as hell. Put it in reverse or dive and wants to stall.
Thought we somehow we knicked the vaccum....that wasn't the issue. Thought maybe we knocked the O2 sensor and damaged it. Changed that. Nope.
Now we are about to change plugs and leads.

Thinking we might try swap back to the original engine mount because it makes 0 sense at all that changing the engine mount would mess with the idle of the car. So frustrating.

Like.....makes no sense whatsoever....
Did you come to a solution?