How steady is normal idle

I have done a search and read all I could find on rough idle. I am aware that the seats will shake a little, all part of its character, that's fine. My engine seems to hunt a by approx. 30-60 rpm most of the time. When I run the fan (heat or cold air) it smoothes out some, easy to notice this. I just got done cleaning the TB and made no difference (it was very clean to start with) As far as the ICV goes I am having a hard time finding it. Looking to the left of my TB I see no screws or ICV, just a hose with a squeeze type clamp (?) First of all is my idle hunt normal? How smooth is it supposed to be? Were is the ICV, any pics? As always, thanks for any info

Ludwig, My idle hunts around 50 - 100 rpms. It appears normal. ICV valve is on the '99s. I believe you have egas like mine. Cheers

Hey Bo$$, If you have one of those digital cameras that can video, you should consider taking a quick flick and posting it up on youtube or something. Probably will go a long way to seeing what's going on with your ride.

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Thanks Chao, good to know this info. I'm still in the early stages of learning... Good idea, will try to get this done when I get some free time to play w/it.

A perfect idle (achieved after I cleaned my TB) is like a sewing machine. Smoooooooth... C.

I have a brand new crate engine with 1700 miles on it. My idle isn't locked. It moves around a little but not much. This is less movement than my 59000 mile motor. In contrast, my wife's 335i idles dead-on with no movement. I don't even think about my idle - it's all part of the machine. -td

Just checked mine this morning. Smooth as silk. I wonder if air temp, humidity has anything to do with it or if the computer takes care of that. Someone must know all the details...

air leak after the MAF sensor. make sure no extra air is getting sucked in at the intake area. try cleaning your MAF as well.

Will take a close look for leaks and clean the MAF later on today (this has not been done as far as I know). Can't hurt Thanks redridge

MAF cleaned (looked clean to start),. No real change in the idle hunting. I took the red fabspeed hose off and whipped the TP clean (did not remove it) w/lint free rag. It was a little dirty but not so bad, no real carbon build up to write about. No air leaks noted. Might just go back to the original intake set up and see what it does, not sure if I can notice the sound dif with after market mufflers in place. Otherwise looks to be normal as Chao has stated. Just seems odd that some say their idle is solid/smooothe and others have this glitch

let us know if the stock intake does the trick...

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this is actually a good idea, we should all get audio of our (warmed up) cars idling, revving a little, and ideally driving away at wide open throttle. Would do well for everyone's peace of mind as a baseline for comparison on these "sound" issues moving forward, especially for new owners, people with PSEs or mods or aftermarket cats, intakes, before & after throttle body cleaning, or whatever. Next time I have the car out in the country I will try to do this.

My X-51 idles relatively smoothly. At start-up it does have a slight "lump" to it when cold....I attribute that to just a sign of the "bad ***" in it waiting to be unleashed!

My 66K '99 idles very smooth. It had a bit of a "lumpy" idle when I first got it, I commented on it to the PP-inspector, who said "they all do that", but it has gone away. I've been driving it a LOT, and pretty hard. Nice when things fix themselves!

Thanks for all the information/input. I will do a clip of idle and post in the next day or two as per Ben-CCC-uniT.

Follow up No video clip, sorry Reason being is that the idle has completely smoothed so I don't feel the need. Maybe I did not give it enough time after the cleanings. I have put a few hundred miles since and it is night and day different . As stated before, the TB and MAF did not look dirty but one or both of those settled down my idle Thanks you all for the help Chao, Might want to look into spray cleaning if you have not done so already. This could make a big difference for you as well. A 50-100 rpm swing might not be normal (?). I'm now holding steady within 10 rpm.

Mine has always hunted around 50-100rpms or so, but is smooth when I have the AC on. I had the throttle body cleaned a while ago and that didn't seem to change anything. It's never stalled or anything, and I'm not concerned with it. It idles better than a v8 with a hot cam.

i actually looked at my gauge to see if i can lend a hand here... and realized... fellas... 50 rpm ... that's barely a twitter on the gauge since each mark is what... 200RPM? the question should be, does your needle gauge move? yes, my rpm needle moves at idle. tiny twitch and if u can call that 50rpm then it's 50 rpm. not 100rpm.

at start, my car is at around 1 hash mark above 1000 RPM. after a few minutes it idles at 1 has mark below 1000 RPM and "hunts" within the limits of the has mark (maybe 50 RPM?). i've got a 2001 c4 with 60k miles, original engine.

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Hi Ludwig, Spray? Can you post a pic? This is for the MAF right? Thanks Chao

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yup, mine does the same even after a full cleaning of the TB. Normal.

if we wanna get porsche nerd about it, it's a beating heart

FWIW, I was in a GT3 this weekend with a digital readout. At idle, the car engine moved around 40-50 RPM or so. It was never locked. -td

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That's right Hello Chao Will not turn down a pic request Got it at Napa. Worked great for me. The MAF is a pain to take off (clip at the bottom) so I got a hex set as well (T-20 was the correct size) in order to take off the 2 screws. Found it to be better to do it this way since I was struggling to un-clip, used to have the same issue w/bras Cost of tools and spray cleaner approx $20 I can't say my RPM's are even moving 50 now, but lets just call that a twitch. I know before it was jumping around quite a bit, not a normal heartbeat

Mine occasionally hunts when it's very hot, like after a track session. The oil pressure hunts a little too, under the same circumstances. I hope it's not a problem!

I've noticed that my idle is smoother if I leave my 996 on it's battery maintainer between drives. (AC on as well) So I'm assuming that the extra alternator load of a less than charged battery is pulling down the idle if I don't use the maintainer. Difference was night and day when I bought the maintainer - for me any way.

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That's interesting...good info to know

Thanks for the info. Mine runs smooth most of the time and will +- 50 rpm at times.

Worth the $70