I wear ear plugs when I start my car. Can't hear a thing. Engine sounds great...

 

nice. i wince in anticipation of the sound i know is coming. earplugs are a good idea ha.

 

Couldn't have said any better.

 

I have never noticed a rattle...the straight pipes on a cold start erase that problem. :-)

 

I wouldn't worry about it. I tore down earlier this year with 58k miles and the only things that really showed much wear were the IMS bearings and the exhaust valves.

 

Noticeable wear at 58,000, stellar! And

 

This is my 2nd 996TT and they both rattled to some degree at startup. I had both of them fully inspected by RUF and was told that it is totally normal intermediate shaft rattle in the Turbos - some are louder than others but it is nothing to worry about. I tend to believe them as they absolutely know what they are talking about. There are tons of threads on this and plenty of suggestions as to oil, filter, additives, etc. I save my worries for other things, usually regarding how my BMW might let me down today.

 

Ims bearing on a turbo???

 

They are shell type bearings like what you find on a connecting rod. They just had quite a bit of surface wear.

 

So, you picked up an LS1 w/o piston slap on cold start?

Seriously, if there are no issues with the small amount of noise, why are you stressing? If you want a luxury car that's always whisper quiet, buy a Benz. And it is really difficult to make out what is rattling on that 917 start vid - it is so loud through the open headers that the cam's mic can NOT cope.

And, btw, the LS1 never won Le Mans....

 

What, you are not running bearings on your IMS?

 

LS motors have many victories at lemans, including class wins and Corvette racing had a overall win in 2001 at 24 Hours of Daytona beating the prototypes.

 

Well out of the 12 ls1, or similar engines 10 of which I currently have, only the 2001 LQ4 has piston slap. If this is a debate over which is a better design, the Chevrolet will win hands down. I have beaten the life out all the ls engines I have, and none had ever popped out a coolant fitting, cracked coils, used much oil, or sounded like a sewing machine at start up. Both of the mezger engines I currently own require that people look to the back of the car and inquire what all that racket is at start up.

I do also currently own a Mercedes w211 e55, sl55 as well as a cls55, clk430, cayenne turbo, and others. I am quite familiar with letting cars sit, and none of these cars or others makes anything closely related to that sound. The closest one is the 2001 LQ4 that sounds like it has wrist pin issues when cold, but also has over 150,000 miles on it.

No real obsession over the blender mezger, just an actual real world speculation that the noises produced by the oil starved parts, aren't benefitting them one bit. The wear may be minuscule, but the noise isn't normal from most machines built in the last 70 years or so.

I am guessing that Porsche engineers didn't design the engine to have no oil pressure after sitting fog a couple of days, I assume it was an oversight? Do the 991 turbo engines have the same normal 996 and 997 turbo rattle? Did they leave that feature in there for the purist?

 

Noises on start ups aside, I watched my oil pressure gauge after reading this thread... I started my car after 6 days sitting and the oil pressure gauge was registering the moment the engine turned over. If mine was reading 0 pressure for a few seconds Id be concerned, maybe the pressure sensor is on its way out?

 

Well, sitting 2 days 997 turbo 39,000 miles, from initial cranking to hint of oil pressure 2.9 seconds.