Help-Engine vibrating at stop

[Deeohgee81]

Hi all,
Ever since I bought my car (used 2001 Nissan Altima) I have noticed that when the car is at a stop (at a traffic light for example) the revolutions drop until it gets to a point where the car wants to stall and then it picks up enough revs to not stall, and this is repeated...basically revs go up and down, up and down...this generates a forward and backward motion in the car.

Any clues what it might be? I have heard that it might be that the engine is "skipping" but i have no idea what this means or how to fix it....for now all i do is put the car in neutral and press the acceleration pedal a bit to increase revs to about 1000 so it stops making the motion.

Thanks for any help provided.

[ExRollen]

What it sounds like you have is an electrical problem. Check your wires to see if everything is grounded properly.

[Deeohgee81]

what type of electrical problem would you be talking about?

[Wayfarer]

I had a somewhat similar problem with my old car. Having the the revs almost drop to a stall on deceleration, and then picking back up just enough not to.


However, what ended up being the problem for me was a sensor and the idler motor. Off the top of my head I can't remember the sensor (O2 or something along those lines).

I am, by no means familiar with the altima engine though, but the sensor could be worth looking into.

Goodluck

[Ben]

is the car an automatic? Is the car shaking as in vibration, or is it your idles just lumpy?

Could be motor/tranny mounts if the car is an auto, alot of times when you come to the stop and stay there with the brake on, the car vibrates a lot due to the fact the car wants to drive forward., and could be an idle stabilizer valve, o2 sensor, valve trouble, or any number of other things.

[Deeohgee81]

The car is automatic, and it is not shaking...its mostly a forward and backwards motion....

[Deeohgee81]

I took it to a mechanic and Wayfarer was right...it was the air intake sensor in the idle whatever....

Repairs ended up costing $498 due to cleaning of the fuel injection system.

[xtreme prelude]

could be a vacuum leak

[rc2002]

The mass air flow sensor on Nissans =

The same thing happened to my parents' Maxima before it hit 80000km. It's a costly part too - That $498 you paid was in USD right?

[Deeohgee81]

Right...I believe the part itself is USD$205, but the rest of the stuff they had to do due to this part failing over a period of time is what cost the rest of the ammount...
That and the fact that mechanics make USD$70 an hour in Atlanta

[Deeohgee81]

Right...I believe the part itself is USD$205, but the rest of the stuff they had to do due to this part failing over a period of time is what cost the rest of the ammount...
That and the fact that mechanics make USD$70 an hour in Atlanta