Idling Issue: holds ~ 500rpm when warm

[skilletrx]

Hey guys - was wondering if you guys have any input in regards to my funny idle:

+ When the car is cold, it'll stay around 800-1000 (normal)
+ When the car warms up, say at a traffic light, it'll fall to 500rpm.
+ When the car is moving, and I put it in neutral to let it glide, it holds 800rpm until I come to a stop.

Any ideas? Is there any harm in my car idling at 400-500?

TIA

 

[JCell]

mine does that from time to time... i dont really worry about it.


it'll also die from time to time if i rev it up "wrong"

 

[justanothermp5]

i think its kinda normal, but people say that you might want to clean your egr
whenever ive been driving for a while and then i turn the car off, and turn it back on a few secs later it starts up fine but then dips to like <800rpms and comes back up

i rev it a little, too like 1.5k and then its all good

 

[skilletrx]

mine seems to be consistent - any other input out there? Also, JCell, how do you rev it up 'wrong'

 

[justanothermp5]

oh and no, theres no harm done when it falls that low
as long as your car doesnt start stalling by itself then your good

 

[BOOSTR]

Factory engine idle speed is 700 rpm. How old are your spark plugs, pcv and air filter. Ever use seafoam to decarbon and in the gas tank to clean the fuel system?
If you have a boost/vac gauge what does the vac read at idle?

 

[dmention7]

Seems normal to me. Especially in colder weather, I've noticed that some days the idle will drop to closer to 500 once she warms up. As long as the idle speed is steady (not bouncing around) and it doesn't feel like it's stumbling or exhibit other drivability issues, I wouldn't worry about it.

Only other thing I can think of that hasn't been mentioned above is that a small vacuum leak could mess with the idle speed a bit.

 

[bradboyd80]

I'm curious about that too. I haven't paid much attention to it though. My idle pretty much stays at 500rpm when warm. I've got new spark plugs, cleaned the MAF sensor and EGR too. Vacuum reads fine, and I've also used fuel system cleaner. But no stalling, so I quit worrying about it. Never hurts to clean the EGR and MAF sensor and the other things mentioned by everyone else, but in my case it didn't do anything.