Engine Whine Noise

[OceanLiner]

First of all, I am new to this Board and it is very impressive. Great advice and knowledgeable members!

I recently purchased (third owner) a MY00 C4 Cab with 12k miles 6 speed. The previous owner (second) installed a Fabspeed Muffler and Headers along with a piggy back computer to max out horsepower and drove the car about 6k in just over two years. The car was loaded with options that brought the MSRP to nearly 102k and it was in showroom condiiton. It's a real beauty and I'm excited to own it.

Now that I am driving the car, I notice a continuous high pitched whine that varies with RPM. Almost sounds like a supercharger (but it doesn't have one). The pitch of the whine goes up with the RPM.

Someone mentioned that all Porsches have this characteristic but usually at redline.

Anyone have thoughts on what it might be? Is this normal?

I'd like to bring it in to the dealer with some info behind me if I can.

Many thanks,

Bob :drive:

[geza]

Congrats on the acquisition!

As for the whine - our 2004 996 40th displays a similar sound/whine, rising & falling with rpm's. Go to your/a dealer and test drive a car to get another reference point. I am sure you will hear the same sound........maybe the Fabspeed exhaust set up accentuates it somewhat...........

[PorschePRH]

check and see if you have an air filter like the K&N type. they let a lot more noise out the intake. considering the exhaust mods, i wouldn't be surprised to see intake mods.

[SilverBlue]

I think what you're talking about is the dreaded "sewing machine" whine that all 996's (normally aspirated) have. It's somewhat masked with a louder exhaust, and an intake kit (CAI or Fabspeed) creates a throatier sound to further help.

John

[OceanLiner]

Well it looks like I do have a normal condition going here. I checked the air filter and it is a K & N. Should I change it back to OEM to lessen the noise?

ALthough the Fabspeed muffler has a lot going for it... It is just too loud for my taste.

Should I consider going back to the OEM mufflers as well?

Thanks guys for your quick response!

[geza]

There are many opinions on the K&N style filter (oiled cotton) vs. the OEM paper element. Various papers have been written that the oiled cotton style allows a greater proportion of super fine grit to pass through the filter, as opposed to the OEM paper elements which seem to do a better job dealing with this fine grit. As for total airflow - one would have to assume that the factory did the job right with filter sizing and paper specification - which would ensure air flow that is more than adequate. Oiled cotton filters do seem to allow a little more induction noise on acceleration - and people in general seem to like that.

Oiled cotton is also able to impact the MAF sensor operation - and can cause CEL events if the cotton is over-oiled.

As for the mufflers - you may want to leave the headers installed, and opt for the Porsche Sports exhaust, which offers some noise modulation if the control system is installed. If you don't want to go to that trouble and expense, then the stock pressed shell mufflers could be the answer. Dansk is a company that also offers OEM style pressed shell mufflers - and if you do your research, the price may be better than OEM factory spares. Of course, there may be some people on this forum who would sell you their stock mufflers.

[OceanLiner]

Thanks for your advice.

I am going to opt back to stock mufflers and will leave the headers where they are as you have suggested.

Haven't quite decided on the filter but leaning toward OEM as well.

[peter-pa31]

Thanks for your advice. 

I am going to opt back to stock mufflers and will leave the headers where they are as you have suggested.

Haven't quite decided on the filter but leaning toward OEM as well.

<{POST_SNAPBACK}>

I have an 04 C4S with under 3K (car was first registered in 5/05). I have the PSE on order, so I will have a low milage set of OEM mufflers. I can't guarantee exactly when they will be available, but it should be in the next few weeks. Also, I don't know if they will fit your car, but I am sure that others here will know. PM me if you are interested.