OK heres the question.When my car is sitting at idle it shakes or vibrates.If you look at the motor you can seen it going back and forth.How do i get it to stop?

 

Well

 

Try a tune up

 

The #1 most common cause for a low speed idle "vibration" is an intake vacuum leak. It's a "miss" disguising itself as a vibration. If that is the ONLY RPM at which you get a vibration I can almost guarantee that's your problem.

SPray around on the top of the engine with a can of carb cleaner. If you hit the vacuum leak source with it the idle with momentarily smooth out and pick up a few RPM. Also, try pinching vacuum lines (rubber ones only- not hard plastic ones!)with a pair of pliers with the engien idling- if you get to one that is leaking the idle will smooth out and DROP a few RPMs. Do BOTH tests and you are 90% likely to find most vacuum leaks.

If you have a high speed vibration at idle then this is not your problem and tracking it down often involves isolating engine accessories by removing fan belts one at a time to see if it goes away. ALso, exhaust systems can vibrate against stuff nearby and drive you bonkers. The heat shield on the cat can also vibrate if one of the spot welds breaks, etc, etc.

That's only scratching the surface. Good luck.

[This message has been edited by Damon (edited August 15, 2001).]