Chirp on Startup?

[mcvgums]

Hey guys, I am new to the 986, but have been on the 996 board for a couple years.

I have a new to me 98 5-speed 2.5L 986 with 65K miles. When I start the car up I often hear a high-pitched chirp, also under very slow speed acceleration. Like pulling into the driveway. It does not seem to be speed sensitive, nor do I feel the tranmission slip. Any ideas?

Do you need more info? :renntech:

Thanks

Mark

[wvicary]

If it happens just as the engine flashes up it could be the starter drive.

[mcvgums]

It seems to chirp at low speed when accelerating in 1st gear as well as 2nd, sometimes it will have several chirps in a row? Maybe a loose belt slipping?

[Loren]

... or bad pulley or idler pulley.

[PAULSPEED]

You could spary a little fanstic on the belts to clean

off the dirt. If the chirp goes away, then you may want to

buy new belts.

Paul

[soopster]

Is it only when the Boxster is cold. Is it more extended than a quick chirp?

I saved this post from a while back since mine does the whining as well:

Originally Posted by ppbon

Most likely it was the secondary air system.

When the car is cold, in order to meet exhaust emissions regs, the car will run a secondary air pump which injects air into the system.

It's located next to the passenger's air vent and sometimes can whine.

Once the car warms up the pump shuts off.

Happy Boxstering,

Pedro

[Glyn]

Loose spark plug?

[wvicary]

Glyn might have it. I have read of others complaining of the odd noise and was a loose plug.

[mcvgums]

The noise continues and it seems to be mostly when the engine is under very low speed torque. I can be in 1st or 2nd, but as I am leaving a stop, but it is not speed related. Sometimes it is a single chirp and sometimes it is less loud and is a series of chirps that are at a consistant speed as if they are related to something spinning in the engine compartment that rotates at a constant velocity.

I am interested in the loose spark plug, but i just cannot fathom how that would produce a chirping sound?

[Loren]

The noise continues and it seems to be mostly when the engine is under very low speed torque. I can be in 1st or 2nd, but as I am leaving a stop, but it is not speed related. Sometimes it is a single chirp and sometimes it is less loud and is a series of chirps that are at a consistant speed as if they are related to something spinning in the engine compartment that rotates at a constant velocity.

I am interested in the loose spark plug, but i just cannot fathom how that would produce a chirping sound?

I have seen it happen - if the spark plug is loose enough then air from the compression stroke leaks out and makes a sharp chirping sound.

[mcvgums]

It definitely sounds like it is worth trying. Any threads on how to access spark plugs and torque specs?

I will report back after I tighten them. Thanks Guys

Mark

[Loren]

It definitely sounds like it is worth trying. Any threads on how to access spark plugs and torque specs?

I will report back after I tighten them. Thanks Guys

Mark

Spark Plug Change Instructions

[phillipj]

I had that chirp sound on my old 996. The guys at the dealer told me I needed a new engine :o .

Thanks to a thread here it turns out it was a loose spark plug.

Needless to say I went back to the dealer and told them the solution :P

Also needless to say I would never even take my lawnmower to them.. :angry:

Hope you find the cause

[mapguy]

The noise continues and it seems to be mostly when the engine is under very low speed torque. I can be in 1st or 2nd, but as I am leaving a stop, but it is not speed related. Sometimes it is a single chirp and sometimes it is less loud and is a series of chirps that are at a consistant speed as if they are related to something spinning in the engine compartment that rotates at a constant velocity.

I am interested in the loose spark plug, but i just cannot fathom how that would produce a chirping sound?

Believe it - I was struck with a chriping noise also, I first replaced the AOS and that took care of 50%. I then discovered I had a loose plug but only after I blew it out of the threads. I had to put a helicoil to repalce the damaged threads. Please check yoyr plug(s)

[mcvgums]

Has there been any other reports of the AOS causing chirping?

[Glyn]

The AOS when it fails usually makes a squeeking sound like a worn out pully bearing, however under acceleration it dissapears - on the overun it starts back again and squeels at tickover like a loose fan belt.

Cant believe you posted the original post on the 21st and your still looking for other answers without checking something so simple as a loose spark plug first

[mcvgums]

Thanks guys, I finally had a minute to look at the spark plugs and found that the middle one on the driver's side was barely loose. Tightened everything to speck and the chirp is gone.

It is funny how such a little fix can make you feel very good about the car again.

Now I am ready to tackle the AOS.

Thanks again to all who helped!!

:renntech:

[phillipj]

That is so awesome!!!!! :clapping: Another "chirping" mystery solved by the old spark plug check!!

Good luck with the AOS

:cheers: