# 2004 4 cyl, rough idle



## 2004D23 (Sep 5, 2005)

Hello all, I am a new member of this forum. I have owned three Nissan products over the past few years (1987 D21 pickup, 1987 Pathfinder, 1999 Sentra) regardless of milage, have had a characteristically smooth idle, hot or freezing cold. It was the way these engines run that drew me to Nissan in the first place. Not to mention, excellent ride/handing, good value for money, and my family's history of owning Nissans. Recently, I purchased a 10 month old 2004 Frontier (4 cyl, automatic) that had every option I wanted, even the right color. Only had 9300 miles at time of purchase. I have only two gripes with this vehicle; 

1) Rough idle when cold; feels like its misfiring due to a vacuum leak. Dealer adjusted idle speed, states there is nothing wrong, and sent me on my way. Still idles the same way, only faster. Runs perfect when in "drive," and slightly better when hot. No engine light.

2) automatic transmission shifts rather rough once in a while, especially in traffic. Has a habit of "jerking" from second to first. Dealer "couldnt repeat the problem" Shifts OK otherwise. 

Anyone else experience these issues? any thoughts on what I should do? This truck is still well under warranty, and has been well maintained (still under 13,000 miles) Any help greatly appreciated.


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## abmobil (Nov 22, 2004)

The ka24de is a great engine but im not sure how ruff yours is but when cold mine has a little vibration coming into the cab as well. Its not ideling ruff cause the rpms are very stable but you can feel some vibrations.
Its the nature of this engine due to its long stroke and not having any balance shafts. Ive never actually watched anyone crank up a 4 cylinder frontier but but ive seen a few 240s with this engine being started and they move all over the place. Again I attribute it to the long stroke.
Im not sure this is right but its what ive heard.


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## 2004D23 (Sep 5, 2005)

*idle*

What im describing is an uneven vibration, as if it misfired, its very inconsistent and affected by ambient temperature. My 1987 pathfinder with a Z24 engine and 200,000 city miles runs smoother, but only by a small amount.


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## Fulltilt1 (May 14, 2004)

Rough at Idle and fine at speed sounds like you could be on the right track with a vacuum leak. Normally these symptoms are found after the fuel is added, cause the mixture is getting leaned out. It could also be a clogged injector and you just don't feel it at speed. How many miles do you have on it? Do you have any codes present? Have the injectors ever been cleaned? You can take them out and have them cleaned and checked for flow. Just some thoughts.


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## rps180 (Aug 20, 2005)

If there is any misfiring, then there should be a code for it in the ECM. There are several different kinds of misfires, and the milder type that the ECM deems will not harm the catalyc converter will not cause the service engine light to come on.
Also, the 4 cylinder in these frontiers do run a bit rougher than the good old Z24 engine. The KA24DE are not known for being a smooth engine, especially when cold.
But just to be safe, try hooking up a vacuum gauge to the engine. Depending on your location it should be between 15~21Hg, and it should read steady and not bouncing around.


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## jerryp58 (Jan 6, 2005)

2004D23 said:


> Hello all, I am a new member of this forum. I have owned three Nissan products over the past few years (1987 D21 pickup, 1987 Pathfinder, 1999 Sentra) regardless of milage, have had a characteristically smooth idle, hot or freezing cold. It was the way these engines run that drew me to Nissan in the first place. Not to mention, excellent ride/handing, good value for money, and my family's history of owning Nissans. Recently, I purchased a 10 month old 2004 Frontier (4 cyl, automatic) that had every option I wanted, even the right color. Only had 9300 miles at time of purchase. I have only two gripes with this vehicle;
> 
> 1) Rough idle when cold; feels like its misfiring due to a vacuum leak. Dealer adjusted idle speed, states there is nothing wrong, and sent me on my way. Still idles the same way, only faster. Runs perfect when in "drive," and slightly better when hot. No engine light.
> 
> ...


My '04 4-cyl (5-spd) isn't what I would call smooth, but it's not really rough either. It certainly doesn't feel like it's missing.

How does it idle in the various gears? Is it just P & N that it idles rough? I wonder if it could be some kind of transmission (torque converter or something) problem.

Of course, the vacuum sounds like a definite possibility.


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## himilefrontier (Jan 21, 2003)

The KA24DE is a bit of a butt-tingler at idle, but shouldn't be missing. Try this: after you just tsart it up, go to the tailpipe and put your hand in the exhaust stream( not covering the pipe, but within a few inches). See if it feels intermittently uneven as this indicates a mis-fire. You could also try an inductive timing light and clamp each wire individually until you find one that "blinks" unevenly. This will be your mis-firing cylinder.


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