car experts, help me out...my car is shaking

i drive a 2000 nissan maxima SE automatic. lately when between 600 (idle) and 1200 rpm my car starts shaking/chugging/hesitating...whether in gear or in neutral. when it gets above about 2200 rpm the chugging goes away. the chugging is at its worst when i'm in 4th gear travelling around 37-40 mph and at 1300 rpm or so. when i turn on the a/c it gets worse...the chugging gets stronger and slower. when i turn off the a/c it gets weaker but chugs more rapidly. my car has lost a lot of power when in low rpm. any ideas of what's wrong? i looked up this problem on the net...all i could find is that it might be a problem with the mass airflow sensor being faulty or dirty.
i had this same problem in the beginning of the year...then it went away for 3-4 months in the summer...now it's back. wtf?

honestly i have no idea. Consider this a free bump when i say i thought this thread was about you getting some.

could be a number of things un-even wheel balance or your axle could be fucked or it could if be something simple as a couple of bolts come loose

most likely one or more of your car's engine's cylinders is misfiring. this will throw the engine off balance. it could be that the mass airflow sensor isnt working or the spark plug or distributor could be malfunctioning. also if you use fuel with a low octane rating in a car that was made for a higher octane fuel it could cause the knocking. what fuel do you use?

could be off timing, it could even be the fuel injection system, there is alot of things that could be wrong with it... to me it sounds mis-timed, but that's just my best guess. did you change any belts or even take any off, yourself right around the time you noticed this problem start? or mess with the distrubtor/spark plugs/spark plug wires? did you change the spark plugs recently? if so were they properly gapped? anyone that could tell you what's wrong would need a bit more information then what you've provided.

trustmymechanic.com <~~~ good forum for help on cars.

I had something like this on my first car which was a crappy 1 litre corsa. Mine would happen when I had been at a constant speed at about 50/60 mph then go into stop start traffic. I thought it was a belt that needed tightening. It might not be the same problem. But mine was hesitant from rest at roundabout and junctions. Dunno if that helps.

ya i was gonna say a belt might have come loose...

It's probably the timing. Although, it could be shacking because of a lean mixture [too much air]

check the air intake to make sure theres no holes in the pipes, as this could be letting more air in than the engine it meant to be reciving.

my suggestions are - (in this order, cheapest to most expensive)

1. put some fuel injector cleaner in your gas tank
2. check your plugs
3. get allignment checked (sometimes free)
4. clean out your air induction, get the mass air flow sensor checked

im 19 and am on my 8th vehicle, ive had damn near every problem you can run into, so lemme know if this helps.

MAN ----ill bet you.ll never ask a question like that here again---ha ha ha
its CALLED MOISTURE......i beleive nissan recalled some harnesses for this prob.................take your plug wires off and spray them with wd40'''
take your plugs out if you can and clean them up too....
has it rained hard in the last couple of MONTHS????
happens to alot of people ....check the area were the plugs go to the cap ---some time the cap gets a hair line crack from over tightening ,,,,,it gets hot on the inside and draws moisture .....its alot worse when it has rained
sounds like your getting a arc....check the inner cap diode..too
ALSO PUT three containers of heat ...its a moisture remover from fuel....maybe thats a prob

NEVER GET GAS AT A GAS STATION THAT IS GETTING FUEL THEM SELVES _____IF YOU SEE A GAS SEMI AT A GAS STATION ___DO NOT GET FUEL FOR AWHILE ....the semi kicks up mad setiment in the underground holders...
you also will get a higher concentration of inner water .....which really makes you think you have huge PROBS but its just WATER=====
I HOPE THIS HELPS -------happy to help