Re: HELP: Strange wobbling sound at start-up. Water Pump??

Hi guys.

I could really use some help with a strange wobbling/spinning noise in my 2002 Boxster.
The noise coincides with the air pump at startup, but comes from the center of the engine. I assumed it was normal (I've heard it for years) but it has slowly grown louder over time.
Could this be the water pump??

I also just started to get CEL codes P1411 and P0401, but I'm thinking that's unrelated.

I'm including a link to a recording of the noise in Dropbox.

Boxster Startup Noise

I'd appreciate your insights/experiences.
.
Many thanks,
-Dan

I can hear the secondary air injection pump in the background.
It's the high-pitched sound.
Once they start acting up they get progressively louder.
A solution is to have the car's ECU programmed to the RoW map with a PST-II or PIWIS unit.
Once that's done you can then remove the pump altogether.
It's only a requirement for the Republic of California anyway.
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Thanks for the responses guys.

Pedro: question... I understand the secondary air pump sound (high pitch) you mentioned. It's sounded that way the life of the car. The newer sound I'm worried about is the lower-pitched, warbling-kind of sound in the foreground, which seems to be coming from the center of the engine. It's not a new sound, but it's quickly grown in volume. Would you mind taking another listen?

Many thanks,
-Dan

... the high-pitched pump. The rest was undistinguishable.
You should remove the firewall (behind the seats) to see if you can pinpoint the cause.
If it's not immediately obvious, remove the belt and manually turn each one of the pulleys and idlers to see if you can feel a worn bushing/bearing.
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

that's the people's republic of California :-)

Grant

gee-lenahan-at-gee-mail-dot-com

At work and it is too noisy to get much out of the clip.

This may be of some value: My 2002 Boxster manifested low volume rumble sound shortly after cold start. This at around 172K miles.

Because the noise was not very loud it was impossible for me to know where exactly it was coming from and fearing the worse I suspected from inside the engine. Thus I went through the trouble of removing the serpentine belt and starting the engine to confirm the noise was not present at cold start with the belt removed.

Since the belt was off I checked all accessory drives for play and the water pump had some. Not much but it had some where as the other accessory drives had none. The belt had a sharp edge, too, which indicated it was not tracking properly. (The belt was very new and I had the old belt handy and it had dull edges so the sharp edge was a recent thing.) So I diagnosed "water pump" and had the car flat bedded to a dealer and the water pump/T-stat replaced. Noise gone. (And the replacement pump has 141K miles on it.)

You should be able to distinguish between a possible noisy water pump and some other source of the noise. You might have to remove the engine cover and expose the engine though.

Also, If you think the noise from the secondary air injection pump you can I believe pull a fuse or disconnect the pump from the electrical harness and start the engine. The CEL may come on if you run the engine long enough but you only run it long enough to confirm the noise is still present or not. If still present you don't have the secondary air injection pump noise to filter out.

You sure about P0401? Maybe you mean to type: P0410?

Anyhow, for P1411:

P1411 Secondary Air Injection System, Bank 2 – Below Limit
Possible cause:
- Secondary air injection pump is not triggered
- Secondary air injection pump does not function
- Air supply lines restricted
- Electric change-over valve does not function
- Air change-over valve does not function
- Vacuum system leaking

I'd be careful about configuring the car to operate sans the secondary air injection pump. While it is true CA has some rather stringent emissions requirements that would make removing this a real problem other states can require a functioning secondary air injection system and the readiness monitor that goes with this, too.

If the secondary air injection system has suffered from some mechanical failure there can still be a problem if the failure is a leak so unless you remove the entire system there can still be a problem arising from the leak. And in removing the system then you have to seal up the hose connections, etc. If not done right this can cause other problems that might be harder to diagnose without the benefit of the DME support for the secondary air injection system and the diagnostic codes it would provide.

... if you determine that the problem is the secondary sir pump, the best approach is my advise above, unless you're in CA.
None of the other 49 States require it or test for it.
I have removed at least 3 dozen throughout the years in both Boxsters and Carreras without any issue.
When the pump is removed all you'll need to do is plug the remaining 3/4 inch hose.
I assure you that if you remap to ROW and remove the SAIP you will not have any issues no matter who says differently.
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

regions of WA state. Denver CO and other areas of CO also have emissions testing and will fail if any of the factory installed emissions equipment is not functioning properly. Tucson AZ, Phoenix, AZ and possibly other areas of AZ also have some kind of emssions testing in place. There are probably other areas but CA is not the only place where proper functioning of emissions equipment appears to be required.

In fact even if emission testing/nspection is not done the 1990 Clean Air Act makes it illegal for anyone, including the owner of the car, to remove, bypass, defeat, disconnect, damage, tamper with any factory installed emissions equipment.

I can here it, and I think I know what it is, and why it's been getting louder...
When was the last time you fed the bongo drummer living inside your engine? Exactly.