I did a search and could not find a good answer. Anyways, I have had my 997 from new for just under a year and it has 12k miles on it. It has always been a little noiser after start up for about 30 seconds. This seems normal based on what I have read here. However, this morning after sitting for two days, the engine had a definite clatter type of noise that went away upon warm up. Starting up from cold later in the day did not produce the noise. Sounds like a lifter or valve train noise. Anyone experience this? Normal after sitting for several days?

 

Normal leak down of oil from lifters. Common when you run Mobil 0W40. Switch to a better oil and you'll reduce or eliminate the noise and related wear.

 

What oil would you recommend ?

 

Well, that subject is a contentious one for some people. Many say you MUST use Porsche APPROVED oil ONLY. The problem with that, is that Porsche changes their approved list more often than most change their socks. What is on the list today may not be on the list next time, depending on whether the oil manufacturer is wiling to pay for the review by Porsche.

If you are among those who believe you must use what is on the approved list, then use the 5W50 Syntec oil, year round, unless you live in extreme cold conditions. In that case, use a 5W40 oil in the coldest months. This will also protect your warranty. Using any of the oils listed in your manual will protect your warranty regardless of what is on the approved list.

I run 15W50 most of the year. This was the factory fill but is no longer on the "approved" list. I have run this oil or 5W50 since the car was new. I burn no oil, leak no oil and have no valve noise. I also run a higher effective compression than any stock TT. You will get many opinions here, but I would never put anything less than a 5W50 when running in mild climates.

 

search for oil and read before you take advice on what professonal internet engineers\technicans recomend

 

I often hear a kind of rattle/pop sound on cold morning start ups.
I got kind of worried and went to see what was up... sounded like the exhaust to me, and is not a rattle once outside, but a pop-burble kind of sound
I thought it was the smog pump that causes this noise from the exhaust when cold.... but i could be totally wrong

 

Totally normal,....and I've never gotten used to it. Some people like the sound! Personally I think it sounds like a chainsaw first thing in the morning.

 

Sounds like a two pack a day smoker clearing his throat 1st thing in the morning. Not pleasant, but you know the car is working. I find the rattle worse if I've not driven the car for a few days.

 

I notice that more so with the S.

 

I thought it was a loose exhaust but when the sound persisted with the muffler change I knew it was something else. Thanks for the insight.

 

my 996 never sounded like this, even with PSE (and that had a great poping sound on start up).
The poping is really close to a rattle sound.
Funny thing is it takes a few seconds to start making this noise, hense the smog pump theory.
If i rev a tiny bit higher (1000RPM vs 750RPM idle) i totally goes away.
It is a little annoying though.

 

Mine sounds like my old two-stroke 50cc Zundapp.

 

Not a big fan of the way a stock 997S exhaust sounds under these and other lower to moderate rpm conditions...the worst is when pulling away from a stop under light throttle; yuck; Car and driver referred to the sound as shaking a giant can of walnuts or something to that effect. Man the sound of my past 930 turbos at start up and any rpm for that matter, was pure bliss

 

I've only had my C4S for a few weeks, and I agree, tone is brutal on slow acceleration. Embarassing in parkades. With all the work the factory does for exhaust tones, they missed it on that one.

 

I got a visit from a good friend that lives in DC (who is also a car aficionado) and he saw my car for the first time today; his first comment was how much he liked the color and his second (upon me starting the engine) was how I needed a new exhaust! I explained to him I think the lame sound has something to do with the Euro noise limits etc. I also said the car exhaust sounds completely different at speed...he did not seem too convinced so later in the day I gave him a taste of a second gear pass accelerating from 5000 to 7200 rpm....he had quite a different opinion after that. I would like the exhaust not to be louder at low r's but to just sound better/more refined.