philooo

argh it just sucks to not have a Porsche shop anywhere close to me. I have to try to find all those things on my own It is a bit stressful. I'll put my stethoscope to work tomorrow, we'll see.

smorris

your signature line says you have an extended warranty... rev it till it dies? I have one too, but they don't cover noises, only complete failures! Sort of crazy as the noise doesn't sound good..

My 2002 has bad cats and one that has a definite rattle at idle that goes away with revs, but yours sounds different, like it is there even with revs, just a bit lighter...

That oil is definitely in need of changing!

philooo

This morning I used my stethoscope to check the engine for noise, and believe it or not, but the screwdriver handle pointed to your ear, works just as good may be better for click noises.

I check the engine, all check points sounded like mild regular clicks or movements. But when I checked the the catalytic converters as one message suggested earlier, The driver side was very quiet, whereas the passenger side cat. converter was making really loud click noises.

I remember the previous owner telling me that one of his cat went dead and was replaced recently, I assume this is just the second fold to this story.

After my sound investigation, I plugged the durametric to check for cat. values and see what I could find to confirm the sound problem. I don't know much about the proper values, but I found one that has very different data from bank1 to bank 2. The value is called 'o2 sensor voltage behind c. bank2'. That one goes up and down on bank 2, while the bank 1 stay always flat.

- Can someone confirm that bank1 is the driver side ?

- Any other value I can check to see if the cat is dead ? are the loud clicks the symptom of a dead cat ?

Dharn55

I think this is good news if it is the catalytic converter. While they are not cheap, they are a lot less than engine.

himself

If it is a CAT, you better run to a dealer. Your 8 years is just about up! With an 03, you might have a late 02 in service date, which means that you expire in 2010!

-td

Ahsai

Yea, bank one is driver's side. It does look like your cat is shot. The after cat O2 reading should be more or less constant (like the blue line) when the before cat O2 readnig should flutuate like in your plots. Your bank2 after cat sensor is kind of following (lagging) the before cat sensor, which means your cat is not working. Your's is '03 so maybe it's still under the federal emmision warranty. Check with the dealer. You may get lucky to get it fixed for free.

philooo

Good to know I had no idea they were warrantied

I'll see if the dealer can confirm this with the serial number on the car

philooo

I thought the Twin Turbo did NOT had IMS ? no ?

BUT

It does sound exactly like my problem.

Dennis C

I'd send a sample of your oil to Blackstone Labs for analysis. Contact them and they'll send you a free test kit to mail back with an oil sample.

http://www.blackstone-labs.com/

philooo

Just called the dealer, the catalytic converter is under that EPA warranty, I was anyway a 03' date stamped on the part. But to fall under the government warranty the check engine light (CEL) needs to be on ! such bias..

anyways last time I remove my air filter and forgot to plug back the MAF, the light came on right away, so I assume I can take care of that!

When that CEL came up, a new fault code came up for the cats, but I cleared them now. As I did not want to drive with that light on the dash. Especially there is a value in the on board computer, that count the number of miles driven with the CEL on. And mine is a nice 0

Oh last thing, if it is the Cat conv. the car need to stay in the shop for a week, as they don't have any car.conv in stock !

philooo

I checked that guy, and he posted a long thread on 6speed
http://www.6speedonline.com/forums/9...t-noise-8.html

apparently he think the noise was coming from the 'crankshaft thrust bearing', do we have same issue on the 996 non turbo ?

roadsession

i told ya it was cats

Get it changed. 80% likelihood that is the culprit.
It's amazing how everyone immediately jumps to IMS vs the most common failure point here - which is cats.

(Do a search on this forum on catalytic converter clicking noise)

Eharrison

http://www.URenginesgonnablowcuztheinteretzsays-so.com

Or
http://www.TheIMSisthisyearsRMS.com

Dharn55

Couple of comments. First I guess for the dealer/EPA a "failure" is that the cat is not working, not that it rattles badly. It might be that if it rattle enough it will damage the cat enough that it will lose function. Second a cat "failure" probably is more common than an IMS failure, but really not in the same category. One effects emissions, the other can destroy the engine. So you really have to define "failure."

Ahsai

Oh forgot to add, with the engine off, hit the cat with your fist/rubber hammer. It should make the same rattling noise. Just another way to confirm it.