Does anyone have the same problem? I recently noticed my engine rattles when idle, it shakes alot, the needle moving up and down between 600-800 rpm, I wonder what it could be

 

i changed to synthetic oil and everything is smooth
how long since your last oil change?

 

is this when youre at 0MPH?

 

you're not driving (moving) at the time right? hmmm, I don't experience any of this, unless it's severely cold out and my needle drops suddenly, but even at that... I wouldn't call it rattling and definitely not shaking...
Do you have a manual? How's your oil? Did you just recently unplug the battery? Is it severely cold?

 

Does this happen when you start up the car after the battery is unplugged.....i had my front sway and NST pulleys installed and had my battery unplugged....later that night at idle i had it vibrate like it was gonna stall....but after a few times it went away and all is back to normal....kind of weird...why does it do that???

 

I see you did an intake, header, etc. This could be due to a sensor malfunctioning. I'd check it out, possibly a trip to the dealer unless you have a buddy who can give you his sensor to try out. I could be wrong though...

 

I got a manual, I use synthetic oil on my every oil change, still about 1000 miles until the next oil change, the rattle shaking does when I am at idle, not moving, it suddently dropped about 100rpms, and it starts there, then I could feel the rattleing, it feels like when you give not enough gas when you accelerate.

 

what sensor? do u mean the o2 sensor?

 

o2 possibly (there is an o2 sensor on the header)....but I was refering to the maf sensor. The maf sensor regulates lean/rich fuel-to-air mixture. The o2 sensor would throw a cel usually if there is a problem there (exhaust issue).

Another suggestion that came to mind - when you get a tune-up (which you should not yet need), the mech adjusts your idle....maybe you just need to have it regulated...

 

This Happened to me as well.