onnastick

Hi all, I apologize for not having that much to go on. I have only had my first Porsche for a couple weeks now, and it's emitting a sound I don't recognize that I don't think is normal. It is a 2006 C4S cab with about 118k miles. It's a high pitched squeal. It happens most (but not all of the time), at first I thought it was when I turned on the engine, but I found that when I just turn the key to the on position (e.g. to get the oil level reading in dash) it does it then too. It only lasts for less than a second but it's noticeable. I haven't yet had someone cause it while I was outside the vehicle to try and localize or record it. Does this sound at all familiar, or anyone with suggestions with what to look for? I will probably be setting up its 120k service sometime in the next few weeks and I could ask them to identify/diagnose but thought I'd ask here first. Thank you.

Petza914

Maybe the fuel pump primes with key on prior to starting. Does it sound like a brief buzzing for a couple seconds as that would be normal for a fuel pump prime. At your mileage, it's possible the pump may be going bad as well, but we don't see a lot of fuel pump replacements on the non-DFI cars.

onnastick

Thanks for the reply! I wouldn't say it sounds like a buzzing at all, and I don't think it lasts quite that long. I'll see if I can get a recording and whether I can localize it and report back.

Michaelc

I have a 2006 S that just started doing the same thing. When I keep the ignition to start the car a high-pitched squeal is emitted from the frunk area, seemingly near the windshield. It's only noticeable when I key the ignition to engage the starter. It's very loud and quite noticable.

onnastick

Thank you for the validation and info. Let me know if you figure anything out and I'll do the same.

Michaelc

I surely will. I'm hoping someone else on the forum has experienced this issue. I find it quite annoying that my car making this horrible noise, not to mention it doesn't sound like whatever's making the noise will cure itself.

ejabour

Count me in also. I have the exact same thing but have not investigated it yet. Part of me is leaning to it being a flap in the HVAC system opening when the key is energized. Someday I might get around to tracking it down.

Michaelc

I was thinking my noise was possibly from the HVAC as well. I hate that idea because a fix can't be inexpensive in that area.

MrMoose

Blower fan spinning up? Make sure the fan is off when you turn off the car, then try again.

CD drive in the PCM or frunk changer, maybe?

Michaelc

I will try with the HVAC off when I start the car and see if it changes things.

Michaelc

I turned off the radio and shut down the auto HVAC. When I keyed the car it made no noise like what I was experiencing. So i turned everything back on, shut the car off, gave it a minute and started it again. No noise this time either. I'm going to let it sit overnight and try it again in the morning.

Ernie Jabour

So, I dig around a little just now. It is definitely coming from the frunk area, wayyy louder than in the cabin. I need another set of hands to turn the key while I isolate further but it very well could be the fuel pump or the cd changer as others have stated.

Here is a video for your listening pleasure.

https://youtu.be/9N8UWBxqKb8

Petza914

No idea what that is, but it's not right.

MrMoose

Yeah, definitely not normal. Only stuff I can think of up there is, as you said, the fuel pump or a CD drive (either the CD changer, or maybe there's a DVD drive for the Nav up there? I don't recall on the 987.1). Could also be something in the fuel vapor system, maybe the DMTL (leak detect) pump?

You could try pulling fuses one at a time, see if it makes a difference (obviously don't try to start the car with the fuse pulled).

[Edit: crap, that's the 987 fuse diagram, lemme see if I can find the 997 one]

MrMoose

Okay, 997 fuses here: https://rennlist.com/how-tos/a/porsc...diagram-376033

D1 is the fuel pump, D5 looks like the DMTL pump and tank stuff, and D9 is the CD/DVD/Nav stuff