Is it normal for idle to be lower in hotter temps?

[boostedtsiawd]

I noticed in hotter temps my car idle drops a bit but when its colder outside its a bit higher is this normal for a old car? I have a 88 Nissan 200sx.

 

[zach1900]

Yes it's normal, though probably your imagination, it goes into lower idle faster in hotter weather, these engines run in a very narrow water temp.

 

[NHGUY]

I have an old truck that idles way faster when hot,vs when its cold...

 

[hansj3]

Yes on a car that old there will be a cold idle phase of warm up. Kind of like an enrichment circutin some carbs

Maybe yours isn't working

 

[4wheeldog]

Electrical load will boost the idle even in cars of that vintage. When it cold, you are likely to have fans/lights/wipers on, all of which will raise load enough to bump the idle up.

 

[3800Series]

Engines run rich when cold. Once they warm up the computer will lower the fuel (at idle) which will result in lower rpm.

Car sits at 1100 rpm when cold but around 700 when warmed up to operating temp.

But I normal crank the ac when I get in so that probably contributes to higher rpm during cold starts.

 

[Lubener]

Originally Posted By: NHGUY
I have an old truck that idles way faster when hot,vs when its cold...


Might check for a vacuum leak.