Throttle Body/Egas Noise

[norcaltim]

Edit: Finally narrowed this down to the throttle body e-gas controller electronics. Previously thought it was alarm-system related, hence a bunch of posts about locks and such.

 

I have a high pitched (~5 kHz) constant sound coming through my speakers while the car is in ACC, same sound + alternator whine when the engine is running. The sound is also present when the speakers are disconnected, and originates from the engine compartment as far as I can tell (not detectable inside, loud near both rear wheel wells). I've tried re-wiring grounds, I've messed with wiring, and I re-soldered the circuit board of my passenger door lock, all with no impact. Any help or advice is greatly appreciated.

 

 

 

Edited April 13, 2017 by norcaltim

[JFP in PA]

If you scan the car with a Porsche diagnostic system, you will be able to read the last ten alarm faults, which should point you to what is causing the beep/red light.

 

We have several customers with some very serious aftermarket audio/video equipment in their cars, and none of them have the issue you outlined.

[norcaltim]

2 hours ago, JFP in PA said:

If you scan the car with a Porsche diagnostic system, you will be able to read the last ten alarm faults, which should point you to what is causing the beep/red light.

 

We have several customers with some very serious aftermarket audio/video equipment in their cars, and none of them have the issue you outlined.

 

Well that's encouraging, at least -- if I figure out what needs to be fixed I can eliminate the noise!

 

I neglected to clear codes last year so as far as I know these codes could be from many, many years ago. But this is what I got when I pulled codes just now.

 

Engine: None
ABS: None
Instrument: 9110
Airbag: 3
AC: 35
Alarm: (nothing "Present")
47 - 11
33 - 14
61 - 58
60 - 3
42 - 3
21 - 1
34 - 1
25 - 1
16 - 1

 

Edit: This is a 2001 base.

Edited March 6, 2017 by norcaltim

[norcaltim]

I did, however, clear the codes a few hours ago, and then locked/unlocked the car a few times.

 

Here's what popped up:

47 -- 1

61 -- 3

 

Everything else (Instrument/Airbag/AC) was clear.

Edited March 6, 2017 by norcaltim

[JFP in PA]

What scan tool was used to obtain this data/

[norcaltim]

14 hours ago, JFP in PA said:

What scan tool was used to obtain this data/

 

Durametric -- I can do a screenshot if that would be more useful?

Edited March 7, 2017 by norcaltim

[norcaltim]

On 3/6/2017 at 5:41 PM, JFP in PA said:

What scan tool was used to obtain this data/

 

Screenshot attached. I'm going to run through the diagnostics from this thread and see if that gets me anywhere: 

 

[JFP in PA]

One or more of your locking systems micro switches is acting up and may need to be replaced.  The alarm beep is telling you that the car is not locked.

[norcaltim]

Didn't find any faults in the locking wiring, pulled both locking mechanisms and found cold solder joints on the circuit board of the passenger lock. I'm going to re-solder that board tomorrow, then check the driver mechanism, then see what happens when I put everything back together.

 

Edit: Re-soldered the board, checked all the micro switches, put everything back together. One of the springs on the passenger lock is a bit worn out, going to see if I can find a replacement before reinstalling.

Edited March 16, 2017 by norcaltim

[norcaltim]

On 3/9/2017 at 11:06 AM, JFP in PA said:

One or more of your locking systems micro switches is acting up and may need to be replaced.  The alarm beep is telling you that the car is not locked.

 

Update: Finally got some interior pieces back from paint so was able to re-assemble the car today.

Positive: My locks now work like they're supposed to.

Negative: No change in the sound.

 

While putting my doors back together I noticed the sound (~5kHz, steady) is present with all of the speakers disconnected and the key in the ACC position. If I get out of the car and listen near either rear wheel well the sound is there. A friend confirmed they also heard it. So... what? Is this normal? If you listen to your boxster's rear wheel wells with the engine off/key in ACC do you hear a high-pitched noise? Is something broken or do I just need to wait 10 years until my hearing in this particular range dies off? 

Edited April 9, 2017 by norcaltim

[norcaltim]

It's the throttle body.

 

It would be super, super helpful if someone could let me know if they hear a high-pitched sound coming from the engine compartment when the key is in the ACC position. If you press the gas pedal you should hear some clicking sounds as well, this might help you localize where you're supposed to be listening. If you happen to have your engine exposed, you'll definitely be able to hear what I'm talking about. My hope is you will hear the clicking sounds (ECU moving the throttle body) but you will NOT hear the high-pitched sound I have.

[Ahsai]

High pitch noise and clicking sound is normal. That's the e-gas calibrating itself.

[norcaltim]

15 hours ago, Ahsai said:

High pitch noise and clicking sound is normal. That's the e-gas calibrating itself.

 

Is it supposed to never turn off?

 

Here's what I hear: the moment the car turns to ACC, a high-pitched noise starts up from the throttle body. Maybe a minute or so later, the noise changes a little bit, there are some clicks, and then it's just the high-pitched noise again. The high-pitched noise is constant and never turns off.

 

I'm gonna go with this, because it makes me feel better: the DC motor in the throttle body is bad. I'm going to put a new throttle body on and hope for the best.

Edited April 13, 2017 by norcaltim

[Ahsai]

No, the high pitch noise should stop. Also, the noise doesn't start till the key is left in that position for some time (say tens of seconds).

It doesn't sound like your's is normal.

Edited April 13, 2017 by Ahsai

[norcaltim]

46 minutes ago, Ahsai said:

No, the high pitch noise should stop. Also, the noise doesn't start till the key is left in that position for some time (say tens of seconds).

It doesn't sound like your's is not normal.

 

This is excellent news.

[norcaltim]

Sort-of related question: why are 986 throttle bodies $1000 while 996/997 throttle bodies are just a bit over $100? Frustrating. If I'm missing something please let me know; I'm looking for part number 986-605-115-01 and finding nothing in a reasonable price range.

 

I've narrowed down the noise to the motor inside the throttle body housing. Since an actual 68mm throttle body is stupidly expensive, I guess I'm going to buy a 74mm and swap the motor into mine.

[Ahsai]

$500 from eBay? http://www.ebay.com/itm/New-Porsche-THROTTLE-VALVE-BODY-to-Fuel-Injection-BOSCH-0280750007-98660511501-/181985648536?_trksid=p2385738.m2548.l4275

 

[norcaltim]

30 minutes ago, Ahsai said:

$500 from eBay? http://www.ebay.com/itm/New-Porsche-THROTTLE-VALVE-BODY-to-Fuel-Injection-BOSCH-0280750007-98660511501-/181985648536?_trksid=p2385738.m2548.l4275

 

 

Yeah... I found a few around that price, but I still don't understand why the hell the Boxster version is so expensive. I ordered a 997 version for $175 shipped.

 

Also, if anyone knows the part number/any information on the motor inside the throttle body (friend at Bosch??), that would be super useful.

Edited April 14, 2017 by norcaltim