niner niner seven

At a car event today when I pulled in and the engine was making this sound. Started 1 mile before I got to the event.

Please let me know what you think is cause/solution. 2006 4S 96K miles. Thank you.

https://www.youtube.com/watch?v=hKrg...ature=youtu.be

Macster

Assuming the car is a manual and depressing/releasing the clutch doesn't affect the noise, or if a Tip and moving the gear selector from say Park to Drive doesn't affect the noise, or turning the steering wheel doesn't affect the noise (and the power steering fluid level is ok), sounds like an idler roller bearing to me.

One in pretty bad shape compared to what I've heard from my 03 Turbo when it suffered a bad idler roller bearing, twice now. First time was a "dry bearing" sound. Second time was a squeak. I have an video/audio clip of the sound I can post if you want.

Best get your car to a qualified shop for diagnosis. My advice to avoid driving the car any and have it flat bedded to the shop.

At the shop the tech will of course lift the car and pinpoint where the noise is coming from.

While it doesn't sound like a water pump the tech will I'm sure check the water pump for leak sign and probably remove the belt and give all the accessory drives a check for excessive (any) play.

niner niner seven

Thank you Macster, it is a manual sorry for not adding that.

I had the car flat bedded to the dealer so they will look at it tomorrow but I am extremely curious.

If you could post your audio clip that would be great.

Thank you for your post.

niner niner seven

After some inspection with another rennlister, my thinking is now that this is the A/C compressor unit. When I turn on my A/C the sounds occurs, and stays on even when i turn off the AC.

I was able to inspect all my idlers with the serp belt off, they look good.


Since my AC is still able to cool the car i am leaning towards a bearing or clutch issue in regards to the AC compressor.

My question is if i continue to drive the car (say to an indy) without engaging the AC will i still be good to do that given the serp belt is rotating the AC pulley at all times?

Thank you

sjfehr

That sounds like a failed AOS; the failed AOS can pull vacuum on the crank-case and creates a screaming sound as air is forced backwards through the crankcase seals (which weren't designed for negative pressure). Consistent AOS failure symptoms associated with the squeal: it takes some seconds to build pressure (and start squealing) after start, and may decrease at higher throttle settings. (A slipping belt or failing bearing should start immediately.) You will also find it nearly impossible to remove the oil fill cap with the engine running- if you start the car with the fill cap off, the screech should disappear. Though be warned: the extra air flow may result in sucking oil into the intake.

I haven't tried it, but temporarily disconnecting the AOS tube from the intake and capping both ends with tape should remove the symptoms, too, with less danger than removing the oil fill cap.

niner niner seven

Spot on, right after I read this post service guy walked up and stated air oil separator was the issue. Having them replace for 500$ including labor. PCA membership gets stealer discount on parts/labor so paid for membership today.

AC compressor needs moved to get to AOS apparently and I don't have the tools currently to DIY.

Thanks to everyone who helped me with my issue.

997_rich

So that was the final diagnosis? I'm surprised you didn't see a cloud of burning oil out the exhaust. Funny you PM'd me about the AC because I also did the AOS last weekend. Do a search on the AOS or look it up in the DIY sticky.

I don't think you need to move the AC compressor to do the AOS. It was just a lot of tedious working with small wrenches etc.

$500 isn't a bad price including labor. The part alone is $100 and it took me about 8 hours all-in (though I did the alternator cable at the same time).

Keep us posted!

niner niner seven

Hey Rich yea I saw your post re AOS. there are also great write ups in renntech and here for both base and S 997 AOS DIYs. Apparently the AOS are in different positions based on the engine?

http://www.renntech.org/forums/tutor...r-replacement/

https://rennlist.com/forums/997-foru...-997-1-c2.html


The tech started my car in the back as I went to discuss w them yesterday and white smoke everywhere.





There is an aftermrkt AOS from the dealer for 180$ PORSCHE part is 224$. They are saying two-three hrs of labor. Then apply the PCA discount.

Agree doing this solo and cheaper part and no labor better option but its something I cannot do myself.


This thread helped me as well:
https://rennlist.com/forums/997-foru...oke-smoke.html


There is nothing like leaving a car event on a flat bed. Came into the event in style, left in style.

niner niner seven

Incidentally one of the techs did find a possible solution to my exhaust tip rattle problem.

here is my post on my ongoinnnnnng exhaust tip rattle:

https://rennlist.com/forums/997-foru...ip-rattle.html

The tech said the weld was cracked off one of the exhaust pipes. I went to the back of the dealership where the car was parked and took some close ups:

thoughts?

997_rich

Re. AOS: I see now.. the M97 AOS is behind the AC compressor. The M96 is by the firewall on the drivers side.

Also a consideration for next time: porsche makes an AOS that's supposed to be more robust for motorsports applications:

http://www.pelicanparts.com/cgi-bin/...-04)%2520%2520

997_rich

Re. exhaust: that should be easy for someone to MIG or TIG if the part is pulled.

niner niner seven

$742!!

Macster

Read this and I had to go back and listen to the audio again.

I would have bet money on an idler roller bearing.

Just shows you these damn AOS's can manifest a number of different symptoms when going bad.

Glad you got the noise diagnosed.

Macster

Here is an audio clip of my Turbo and what proved to be a bad idler roller bearing.

View My Video

997_rich

Reading around I'm hearing that the stock AOS lasts around 70k miles. Mine lasted 120k miles. I wouldn't be surprised to put another 100k on this car. If it fails again I'll go with the $742 version so I don't have to do it a 3rd time.