Ok so basically my car during idle regardless of warm or cold once the idle starts to fluctuate from 1000 and stutter ever so slightly to 800 then back up (which from what I read is normal for our 8's) it makes quite an audible snapping sound. It never did it before I worked on it for the weekend (suspension only) and now makes that sound every 8 seconds only under idle. There is no power loss, no misfiring and no difference whatsoever performance wise. It can't be the engine since it's that long of a duration before making the noise.

Anyone have any issues like this? It only makes it once the dip in RPM occurs and makes a *snap* before it picks back up. I'm not exactly sure what it could be.

BHR coils and new plugs only have 8-9k on them. New AEM intake installed and used for only 1-2k miles this year. MAF is all cleaned. Fuel trims were reset. All of this was done before the issue about 1-2k ago so I'm not exactly sure if it's tranny/clutch related or not. I am due for a tranny fluid swap which I plan on doing (@ 31k currently) but doubtful that's going to fix anything.

Anyone else have this sound in the past?

 

have heard of something similar occuring in one of those S&M sessions ...

Seriously , I would get under it while it's idling and try pinpoint where the sound is coming from

 

Yea...that's tough for me, namely because my hearing is not that great. I however have a better feel of things than most so I can pick up erratic vibrations or issues by feel alone that others cannot and instead do so by sound.

 

that snap sound anything like a spark jumping a gap ?

 

lets rule out the obvious first: you sure it's not the clicking / ticking noise of the AC compressor?

 

No, it's not the AC. AC was not on when I started it last night. And it doesn't care how hot the engine is. It did it on a cold start up after a few minutes, and just now starting it up after shutting it off 20 minutes ago oil is still hot and water and it's not doing it. It only does it once the typical seldom erratic idle occurs

It's sounds more mechanical than anything and perhaps coming from the driver side moreso than the passenger. The only relationship I can establish is it occurs once the RPM does the typical dip down to 800 and slightly back up. Right at the bottom of the dip *snap* and then waits until another 8 seconds goes by waiting for the drop again. The RPM has always been like this since I've bought the car and to be honest is typical contrast to other manual's I've owned. I'm not worried about it slightly fluctuating, but the sound is stumping me.

And no, it doesn't matter if the clutch is in or out.

Some other notes: SOHN adapter being used since 10k ago, oil is up to level, only thing that I changed about 500 miles ago was starting to pre-mix but I doubt that has any relation to this problem

 

bump, anyone got anymore input?

 

I mean, this sounds EXACTLY like a mechanical clutch or relay being thrown and a power drain placed on the alternator. I even think my car DOES this when it is hot out, but I never put much to it.

Now that I think of it, it might have something to do with the fans being switched on.

Sorry if that is no help.

 

Not sure it's clutch related to be honest, it doesn't matter whether clutch is engaged or not and like I said, regardless whether you started the car up for a few minutes or got back from a daily drive. Whenever it does the erratic idle it makes the sound.

From what I could feel, it's mechanical, not just a sound. I can feel it make the snapping noise slightly.

 

I am not saying THE clutch; I am talking about any electromechanical clutch like what is typically on AC condensers and the cooling fans.

 

Lift the hood and listen for it, if it's a click then something that sounds like fans coming on is normal!!

 

No, this is not normal. Not has it ever made this sound until now. Read my 1st post, 8 second intervals between the sound, happens when RPM hits the bottom of the erratic idle from 800-1k rpm. Right when it drop it makes the snap sound which is very audible.

 

Bump more info please have the same problem