# Rough Idle



## minmax (Jun 14, 2005)

What's up,

I have a few problems with my Maxima...nothing major, but this one bothers me the most, because it's the toughest to troubleshoot. I have had a rough idle for a very long time. I think my idle speed is correct at about 1100 rpms, so I ruled out any kind of idle control valve, etc. do notice when sitting at a stop light my idle can be constant or erratic (the needle will jump around a bit). I also notice if I turn on my lights or the blower motor, it will also jump around. I looked up rough idle and it could be a million things that is causing it. Let me know what you think.


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## brianw (Feb 25, 2004)

Idle speed should be around 650-850rpm, not 1100rpm, unless you are referring to the high idle speed for when the motor is cold?


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## minmax (Jun 14, 2005)

*My bad*

It's idling at 600 rpms, but it does fluxuate between 600 and 700.


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## royson345 (Jan 14, 2005)

I had a rough idle also. it turned out to be my motor mounts were shot. Have checked into how old they are and what kind of shape yours are in?


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## rvanders37 (Jan 1, 2005)

minmax said:


> What's up,
> 
> I have a few problems with my Maxima...nothing major, but this one bothers me the most, because it's the toughest to troubleshoot. I have had a rough idle for a very long time. I think my idle speed is correct at about 1100 rpms, so I ruled out any kind of idle control valve, etc. do notice when sitting at a stop light my idle can be constant or erratic (the needle will jump around a bit). I also notice if I turn on my lights or the blower motor, it will also jump around. I looked up rough idle and it could be a million things that is causing it. Let me know what you think.


you are correct this could be caused by a lot of things. try the easy stuff first. hook up a vacuum gauge and see if you have good vacuum. sb 17-21. if it's low you have a leak. if it bounces all over the place a valve could be the culprit. look for a vacuum line that is split or disconnected. next check the air filter. after all that is exhausted and the problem is still there i'd start troubleshooting components like the idle air control valve, the throttle position sensor and the mass air flow sensor. only replace a part if you can verify it's failed.


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