Hi all,

I've only had my 2006 997 C2S for a week, so I'm still trying to getting to know the car.

I've noticed quite frequently when the car is at idle, the RPM fluctuate slightly between 700 to 800 RPM. If I give it a little revs, it will stabilise briefly but will start to fluctuate again after a few seconds.

Here's the video of it:
Is this normal? The car was mostly parked during the last 6 months before it was sold to me. It currently has only 38000 km on the it.

I'll probably bring it to the shop this week, but want to get some opinion from here to see if this is normal or what might have cause this (intake air flow / sensor)?

Thanks.

 

I had this happen, but it was more obvious. I had my plenum cleaned and it never happen again. It's a DIY job. Just take off the air box hose that goes to it and clean it out.

Should help.

 

Thanks, RaidersR1

Is this (the one on the left) that needs to be cleaned?

http://i986.photobucket.com/albums/a...6a14c032_o.jpg

Thx.

 

Is the AC working fine? If the compressor is cycling on/off that will do it also.

 

The AC works fine. I've tried it with the AC turned on and turned off, and it didn't seem to make any different to the RPM fluctuation.

 

Probably meant to type "throttle body" not plenum. Spray it with throttle cleaner (available at every auto parts stores and maybe Walmart) and wipe off any residue.

If that doesn't calm the fluctuations, try cleaning the MAF with MAF or electronics cleaner. See the DIY instructions in the DIY thread.

.

 

Yes to the OP and yes to Alpine-Al. Words failed me to think of throttle body. Doh...

 

Got it. I'll check these out. Thanks

 

hello simon did you check out the car about the idle fluctuating problem. I have the same problem and just want to see you fixed and how to fixed. what should I tell the dealer regarding this and they will inspect and change the necessary parts. thanks
my email is alexlaw888@gmail.com. thanks

 

You may want to seafoam the engine through the throttle body. Same basic pricipal but you run the car with a small red tube (think WD40) inside the throttle body and pumping the seafoam in aerosol form into the intake while it runs. You do this until 1/2 the bottle is gone and then shut the car off for approx 5 minutes. This allows the seafoam to agitate any carbon buildups inside the throttle body as well as the enigine internals. When you start it back up be prepared for a ton of white smoke; let it idle for a few minutes and then go drive aggressively for about 15 minutes. I use it on all my vehicles as a preventive measure annually.

Works pretty good and there are plenty of youtube videos on seafoam for the faint of heart to watch.

 

I have the same problem and I asked my service adviser. He said that is normal.
Is this normal?

 

It is normal. My car has done this since day one. Indies and p-car dealer all have said it is normal.

 

I will try to clean the plenum and see if it help.

 

Hi Alex,

My car was due for a service so I had it done and the fluctuating is a lot less. It's still there but only a little bit. Been driving it for about 6 months and no issue at all.

Cheers.

 

Your motor was (and is still) fine. Enjoy. Btw, ne one running any type of fuel injector or top end cleaner thru the engine should change their oil afterwards. The manu's are not always upfront about that in the instructions but I have called and spoke to a company engineer for major producer and been told "Yep".