Mechanics

ENGINE RPM"S

2003 Nissan Altima

Engine problem
2003 Nissan Altima 4 cyl Front Wheel Drive Automatic 116000 miles

I have a 2003 Nissan Altima that after the engine warms up the rpm's at idle will flucuate up and down. When you start the engine while cold it seems to idle normal. Do you think this might be a exhaust manifold leak or losing vaccum?
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Toebud
January 27, 2008.



You may have a vacuum leak, get a can of spray gumout, spray the vac lines and maniflod area, when the idle changes, youve found the leak! You want the engine running and spray on the outside but do direct the stream onto the hoses, if it is a vacuum leak, the engine idle will change speed, then you have detected a leak, repair the vacuum leak and see how it runs!
If no leaks, check the Idle air control valve.

Merlin2021
Jan 27, 2008.
Thanks

Tiny
Toebud
Jan 27, 2008.
Your Welcome! BTW if your check engine light is on, go to Autozone and have the codes read, they do it free, then post the code(s) here!

Merlin2021
Jan 27, 2008.
[quote=" merlin2021" ]Your Welcome! BTW if your check engine light is on, go to Autozone and have the codes read, they do it free, then post the code(s) here![/Quote
The code was P0507.I checked for a vaccum leak and had no luck finding one. I cleaned the throttle body. Where would the idle air control unit be located on this altima?Any info much appreciated
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Tiny
Toebud
Feb 1, 2008.
Here's what you need to check...the part is electronic on your car...electronic throttle control actuator....


http://www.2carpros.com/forum/automotive_pictures/62217_p0507Description_1.jpg


http://www.2carpros.com/forum/automotive_pictures/62217_Elec_Throttle_Control_1.jpg



http://www.2carpros.com/forum/automotive_pictures/62217_p0507_1.jpg



http://www.2carpros.com/forum/automotive_pictures/62217_p05071_1.jpg


Merlin2021
Feb 1, 2008.
Idles needs to be relearned with a capable scan tool or the throttle body assy needs replaced and the idle relearned by a capable scan tool.

Tiny
Lostinmars
Feb 1, 2008.
This is what happens when people need to be edjucated...they give bad advice...Relearn proceedures without Consult II tool are as follows...


http://www.2carpros.com/forum/automotive_pictures/62217_Relearn_2.jpg



http://www.2carpros.com/forum/automotive_pictures/62217_Relearn1_1.jpg



http://www.2carpros.com/forum/automotive_pictures/62217_Relearn2_1.jpg



http://www.2carpros.com/forum/automotive_pictures/62217_Relearn3_1.jpg



http://www.2carpros.com/forum/automotive_pictures/62217_Relearn4_1.jpg


Merlin2021
Feb 2, 2008.
Well since you didn't suggest it i'd say that you've never seen it happen. You can take that mitchell procedure and chuck it. The right way is with a capable scan tool.

Tiny
Lostinmars
Feb 4, 2008.
You may be right! But it won't hurt the guy to check it out.

Merlin2021
Feb 5, 2008.
I took the car to a certified nissan dealer and they checked and reprogrammed ECM and cleared code.
Car seems to be idling at normal speed now

Tiny
Toebud
Feb 14, 2008.
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