Hey, everyone, I'm new to the forum and pretty new to owning an S2000. I haven't owned it long, but I've noticed something that's bothering me and I was hoping to see if anyone else had any experience with this problem.

After the car has warmed up, when I depress the clutch and the revs are returning to idle, they don't stop at the 800-900 range the way it is supposed to. Instead (and to varying degrees), the revs will dip lower than the normal idle and then either bounce back up to the normal idle or bounce above the idle before settling into the correct rev for the idle. Again, it varies, but sometimes the dip is so pronounced that the car shudders (as it would if you released the clutch without giving the car enough gas). Likewise, the "bounce back" varies although when it doesn't bounce back to the correct idle immediately, it never goes very far over it, either. It's really that initial dip below the correct rev at idle that concerns me the most, especially when it causes the car to shudder.

I bought it used, but it is certified, and I took it to the dealership. At the risk of prejudice, I will say the dealership doesn't have the best of reputations. In any event, they said this rev "dip" was normal and that all S2000's did it. I've owned my fair share of different cars and have never had a car do this; however, I know the S2000's engine is like nothing I've ever owned either, so I'm kinda at a loss. Anyone had this problem or noticed this behavior? Is it normal or is the dealership just trying to ride it out until the warranty's out? Any help would be greatly appreciated and thanks for your time.

 

I think its normal mine and my friends s2k do it, his a 2002 mine a 2003.

 

My '02 will dip down and come back up, but not to the point of almost stalling. If it gets to a point where it stalls, I would have it checked. As for now, I wouldn't worry about it.

 

I guess you just didn't own the "right" share of cars. Both my Vettes did this and my Viper did it too. The S is not different except that it is a much higher strung engine (power per displacement) than any of the 2 cars I mentioned. It's a "characteristic" and an idiosycracy of this car - one that has been seen in other cars before it.

 

Mine does it also. I have an '05

 

this exact symptom gets posted probably 2 or 3 times a week.

you may hear people suggest you clean the TB, however, that's an unecessary step and could actually be potentially damaging if not done correctly.

Here is what you should do.

The most common reason for this "problem" (and i say "problem" because technically it's not a problem, it's normal)is a "confused" ECU. with drastic temp or humidity changes, the ECU gets confused and this dipping idle symptom occurs. DO NOT give it gas when it does this, as this will only make the ECU take longer to "re-learn".

If after a week, your car continues this behavior non-stop every day, then try the map sensor whack. if that's not it, try cleaning the IAC motor. if that's not it then you'll possibly have to replace the map sensor and/or the IAC motor.

cleaning the TB is a dangerous way of cleaning the IAC. people think that the action of cleaning the TB fixes the problem, when really, they are inadvertently cleaning the IAC. you can clean the IAC motor without having to do the "spray crap into the TB" procedure.

 

First, thanks to everyone for responding with helpful advice. I definitely appreciate all the input and will listen to the voices of experience. Second, I apologize for posting something that had appeared before (multiple times even). I did a quick perusal through the FAQ's intially and didn't see it (although I did see it the second time I looked, so my bad). Finally, easy, guys. I'm not knocking the S2000 for this. Heavens knows, I love the car. That being said, you and I have owned at least one car in common, xviper, and none of mine ever had this problem, notwithstanding the speculation of whether I've owned a "right" car or not. Thanks again for everyone's help. It is greatly appreciated.

 

no i wasn't trying to say you should have searched, because honestly, a search on this subject would only confuse you more. my point was that since it gets posted a lot, we know what the causes are and aren't.

also, no one said you were knocking the S2000. just merely implying it has its nuances.

 

yup happens to me too. I think its the ECU adjusting itself, right?

 

usually yes. assuming it doesn't last more than 6 or 7 days in a row.