Why does my 1997 Nissan Altima have a Rough Idle?

Question

I have a 1997 Nissan Altima that has just reached 200,000 miles. I have rebuilt the transmission, replaced the alternator and battery, new distributor, new mass air flow sensor, new spark plugs, and new air filter. My car idles rough when i have the car in Drive, but come to a complete stop. If i turn off the A/C, I notice a slight improvement but it still idles rough. However, when i place the car in park it idles just fine. Do i need a new engine? My car was running great before this started to happen.

Answer 1

My 1994 Nissan Maxima has the same problem - I'm blaming the idle air control valve at this point.

It's not a real big deal it's just your idle speed is lower than it should be, for my car 750rpm is optimal and it can dip to 500rpm but it may be higher for an Altima since it has a 4 cylinder you'd have to check a manual on that.

Answer 2

hello

Hi, have the idle positioning switch checked.

Answer 3

I see that you have put some miles on it but also replaced some stuff. My first question, (figuring from what you said) is when was the last time that the fuel filter was replaced? On some similar year model Nissans, I have seen that that the fuel filter (according to the manufacturer) was supposed to be replaced every 30,000 miles. I would suggest giving it a shot.

Answer 4

Sounds like possibly a bad engine or transmission mount

Answer 5

No need for a new engine. I would check your oxygen sensor, if its never been changed then it is time to since most new cars call for them to be changed every 100,000 miles or so. It seems a load on the engine causes this rough idle. Does it feel like the motor has a miss to it? or does it just shake? If it shakes but no miss I would suspect one of your motors mounts are bad/ loose.