OriginalFive

at idle...its suppose to be at 1000rpm right? what if the car drops idle to like 900, then drops to like 700-800, then goes back to 900 and sits there...when at a stop, it idles at 1000rpm, then drops again. the car doesnt feel like its gonna die, the idle just drops a bit. is this normal, or does it have to do with the throttle or something? im just concerned, thats all. could it be the throttle and all the build up? or....

thanks

slalom44

When the stock engine is cold, the rpm is a little higher than normal. Once warmed up, the engine idle should be somewhere around 800 rpm. If you have your A/C or defroster on, then the rpm will bump up when the condenser kicks in. With a low fan setting, the A/C condenser can kick in and out pretty often.

Otherwise, the idle should stay pretty constant once the engine is warmed, and it shouldn't be as high as 1000 rpm.

Wisconsin S2k

if you give it a little gas, the rpms may drop very low and then come back up.

but if the car is warm and up to temp. and you're just sitting there in neutral. and the rpms keep bouncing around, that's not really normal. i think i have seen others say a map sensor can cause such behavior.

Billman250

Had an 02 with an idle issue here last night, new map cured it

OriginalFive

thanks for the info, i really appreciate it.

i just thought i'd ask and get some opinions.

S2KSpaYellow

When mine idles the RPMs will fluctuate a little. When they drop slightly I can hear an electric motor running. It is not the radiator fan. Maybe it is the air pump? It sounds very fast and high pitched. I guess the electrical current needed to run this motor puts a load on the alternator and pulls the R's down slightly.

kenhoeve

I have recently experienced similar symptoms. Even warm the idle is a little lumpy, and has sputtered a couple times. I would guess a dirty throttle body could cause it. I recently had the 40k service done at the dealer, is that not part of their major service? I'll take a look at the TB, I know I have to do it on my Volvo about every 40k.

Beside that, I guess a mass air sensor would be the culprit.

bdo

I know this thread is kind of old but....

I took mine in to the dealer mainly to have them fix some unrelated things, but also mentioned that the car had stalled at idle a couple times. They said they noticed it didn't idle quite right, and they replaced the idle air control valve. It seems to idle at a more constant RPM now, but it could be my imagination. Anyone had any experience with this part going bad?

Billman250

No mass air flow sensor on the s2k.


Only IAC valve I replaced on an s2k was seized from sitting, the idle was bouncing up and down from 1k to 2500.

kenhoeve

sorry to resurrect an old thread, but in the interest of closure, i believe it necessary.

The throttle body cleaning did the trick for me. I have no idea why this is not a part of regular service at the dealer. I even asked them why it wasn't and they just shrugged.

Slightly lumpy idle, clean throttle body as first fix try. peace.