# 99 Altima XE high idle



## rowekmr (Nov 8, 2014)

I looked at a "project" car at a lot. Its a 99 Altima Xi with 185k that has a high idle at start up in the cold (10F). Is this something that is worst taking on to repair?
Thanks


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## rogoman (Dec 16, 2004)

Define high idle. Most 4 cylinder altimas I have ever owned ran a cold idle of about 1500-2500rpm. The '99 altima uses a thermo-element to control the idle speed. If your high idle continues after the car is warmed up, then you need to replace the thermo-element on the throttle body. Two coolant lines run to it, it is essentially a wax-packed servo that controls idle speed depending on temp.


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## rowekmr (Nov 8, 2014)

It idled at 2000rpm and when I shifted into gear the car shuddered when the trans shifted at that rpm then lowered to 1000rpm in gear when cold.

So you are saying that this is normal then?

I thought it would lower when I hit the brake to shift car into gear. Car is an auto.



rogoman said:


> Define high idle. Most 4 cylinder altimas I have ever owned ran a cold idle of about 1500-2500rpm. The '99 altima uses a thermo-element to control the idle speed. If your high idle continues after the car is warmed up, then you need to replace the thermo-element on the throttle body. Two coolant lines run to it, it is essentially a wax-packed servo that controls idle speed depending on temp.


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## rogoman (Dec 16, 2004)

When the engine is stone cold, it will idle high, like maybe 2000 rpm as in your case, while the transmission is in park or neutral. As soon as you shift it into drive or reverse, the rpm will drop down to somewhere like 1200 - 1500 rpm while still in idle. Once the engine has warmed up, the idle will drop to it's standard of 750 - 800 rpm.


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## smj999smj (Jan 1, 2006)

Might be worth checking/adjusting the base idle setting and ignition timing setting per the FSM. The idle adjustment is a little "hidden." The IAC is on the bottom of the intake; if you look through the #1 & #2 intake runners from the top, you can see the idle adjustment screw.


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