BED997

I've got a squeal that occurs during start-up and goes away after about three minutes of warming up. Can anyone identify the likely issue?

My guess is a tensioner or bearing in a pulley going bad. The alternator was replaced 3,100/ miles ago (11 months ago), and the serpentine belt was replaced 9,200 miles ago (2yrs, 2 mos ago).

Here is about a 10 second clip. It appears to be coming directly to the right of the alternator.



Thanks for any help

USMC_DS1

Do you notice any fraying on the edge of the new s-belt? if so then you likely have a bad pulley somewhere. If you can remove the s-belt and check each pulley out for bad/rough play. There are some DIY's on the sticky which should help. Any notable coolant leaks... the WP is a likely suspect if you haven't replaced it by 50K mile. It doesn't happen often but new parts(alternator and s-belt) will sometimes fail prematurely so don't rule these out. Let us know the outcome. BTW, nice wheels.

Macster

Unless you are prepared to get your hands dirty just take the car to a qualified shop and demo the noise or describe how to demo the noise.

Chances are very good your car will not be the first in with this symptom and the diagnosis can be made in the time it takes a tech to take a sip of coffee.

I can't listen/view the clip -- no Flash Player and no desire to install it since it is being abandoned by Adobe -- but based on your description an idler bearing or even a tensioner roller bearing going bad is possible.

If you want with the engine off and cold feel the serpentine belt's edges. A sharp edge strongly points to a belt that is mistracking and this then points to an accessory drive that is wearing out, developing excessive (any) play in its bearings.

Either a noisy bearing or an accessory drive with any play is not good. A snapped belt can strand you at best and at worst it could damage something of the engine or in the engine compartment as it lets go.

If the noise is an accessory drive if it is a water pump -- and these are often the source of noise in that area of the engine -- if the pump fails, well, a water pump is not a part you want to wait until it lets go to replace. If the water pump is diagnosed it wants to be replaced ASAP.

A less likely source is a noisy secondary air injection pump. However, this pump does not run for 3 minutes even after the coldest engine start at least not in my experience.

A test to eliminate the possibility the noise is coming from inside the engine -- I do not suspect this only include this test to be complete and keep my post word count average up -- is to remove the belt and then start the engine.

If the noise is absent, which is what I would expect, fine. If the noise is present, not fine.

Be sure before you remove the belt you note its direction of travel and its routing. Do not rely upon your memory but take pics.

Sincerely,

Macster.

BED997

Thanks USMC and Macster - I should have mentioned it is a CPO car under warranty with 33,200 miles.

I wanted to get some help from the experts to narrow down what it could be before I let the dealer touch my car.

Thanks USMC - BBS CHR's.

Mike in CA

That sounds similar to a noise I recently experienced in my '09 997.2. It turned out to be the water pump, which was replaced under warranty.

mattxbart

I would say water pump, but it also could be the air oil separator. Mine, an 07' 997 C2S with 70K miles was making the exact same noise. Did it on start up but went away just after the engine warmed and the idle dropped... Took it to the dealer twice hoping they would do something but since they couldn't see coolant or anything wrong they wouldn't touch it. Couple months later on a 2 hour drive home the noise became apparent at freeway speeds. Turned the car on the next morning and got the engine light. On the way to the dealer it was really noisy. Pulled into the service area and the manager ran outside and told me to shut off the car. Apparently the noise is from air sucking through the rear main seal, the tech also confirmed that the oil cap couldn't be removed when the engine was on (if I were you I would try that as a simple test). They replaced the air oil separator and water pump under warranty. Main seal might also be damaged but since it isn't leaking oil yet they left it alone.

BED997

I wouldn't have expected the AOS. Were you getting smoke at startup? I've never added oil or had a cloud when I started the car, and have no soot on the tailpipes.

I'll try the cap test and see what happens...

mattxbart

I would have never guessed AOS either but when I pulled up in the service area they knew exactly what it was just by the sound. They literally jumped out of their desks and ran outside. It sounded just like yours but much louder at speed, and at idle. I never had any smoke, but after the car was shut off you could smell the oil. Not just the faint, normal engine smell...it was much more pronounced. Now that it has been replaced there is no high pitched noise and the smell is gone.

I think my case was extreme. I bet yours is the water pump or idler pulley. Unfortunately they won't replace a water pump under CPO just because of the noise. They probably have to see coolant. Maybe your dealer is different than mine but I took it in twice to try and get them to act on the noise but no luck. It was only after I left the car on with the noise blaring and check engine light on that they decided it was time to do something.

JasonKM

BED997, any updates on this?
I have similar noise on my 2007 C4S that is present only for a few minutes following a cold start. I have CPO coverage until June 2013 so I was going to wait until the spring to deal with it.

Macster

Postponing getting things like this noise business taken care of is not something I tihink should be put off in the case of having this done under warranty.

While the car's CPO coverage runs until June and you probably have time to have it addressed before then any warranty on the work to fix whatever is found wrong, the parts used, only runs as long as the CPO warranty runs.

Thus say you take the car in the day before the warranty runs out and pick it up that same day, at COB, the next day when the CPO warranty expires so does any warranty on the repairs.

Now sure if the day after something related to the repair failed you'd probably (probably...) get goodwill.

My advice is to if at all possible get the car in and get this sorted out *before* you put the car away for the winter so when you roll the car out of mothballs next spring you have some time to put some miles on the car and give the repair a shakedown to build up confidence the repair was done right and that also the correct repair was done.

Sincerely,

Macster.

function12

I say the pulleys. I just had them replaced on my 07tt. CPO covered it.

BED997

I'm CPOd until spring 2014 ( sorry put wrong year before Macster). I didn't hear the squeal last time I started the car (Sunday). I wonder if it is a function of sitting for a week at a time. That video is after sitting for 10 days.

Spokane5150

Sounds like mine did when my belts went bad. Spray some belt dressing on the belt and see if the noise goes away. If it does then replace the belt. It'll take you about an hour and very easy DIY.

RED HORSE

When my AOS bit the dust on a previous Porsche I told the service writer I thought it was a pulley.

alexb76

Was that when engine was cold/start of the day? or sounded like that at any time?