Hola guys ( and girls),

I'm new to the site and porches, so I'm not that familiar with the site just yet.... but I'm the owner of a 997 gt3. I've had the car for abt a month and I'm currently at the end of my 2000k break-in period ( as recommended by dealer - New Country CT). The last two mornings(27 and 28/june) I've started the car up to hear engine knock. The car will fire up and 2-3 secs later I will hear what sounds like a "metal" drum roll( for lack of better words). It will last a second and then the car sounds fine. I have no issues during the day when starting the car up again and the engine sounds fine during the course of the day. This has only occured in the morning on the first start up(ie, after the car as sat all night). I've taken it back to the dealer and he needs to have the car over night so they can recreate the senario. My thought is a stuck lifter ?? I've done the breakin as recommended and haven't come close to 4200rpm's..I'm wondering if anyone else has had this problem??

 

I'm certainly not an expert, but I have had this problem occasionally with the 997 GT3 and also with an '04 C4S. Please totally ignore the occasional rough start. I think what your describing almost feels and sounds like a diesel truck engine starting and then "puttering out." There's nothing wrong with the lifters or anything - it's just the way the valvetronic settled after you shut the car down. It self corrects after a few seconds and does no damage what so ever. In fact, you might even see a big plume of white or grey smoke when this occurs. As for the "break-in" period. Keep the rev's below 6K and vary the rpm and gears around town. Don't lug the engine, keep the rpms above 3.5K to 4K in each gear. Accelerate at 80% throttle opening if you want. The engine needs to be run through the rpm range. Don't baby the engine. Proper break in will give you a better runing engine and an engine that's less likely to have oil consumption problems. The break in period is simply to allow the drivetrain to wear in smoothly. After 1000 miles, drive it like you stole it.

 

2000 miles and no 8400 shift gear?!?!?!
now is time to enjoy the car bro!!! C mon!!!

 

you will never get those 2000m back.......better make up for lost fun!

 

Mine does it as well. Are you using gas with ethanol mix?

 

Normal, my 996 Gt3 did the same thing. It's sounds like marbles in a tin can. Do a search, it's been discussed and explained numerous times. Remember you have a 6 cylinder race engine that puts out 415 plus horsepower, it's made to go around a track over and over again without any issues.

 

Not a GT3, but when I bought my GT2 I drove it out from the dealer sideways, like a scalded dog,no break in for me!! It has30K miles on it, and it's working perfectly, no issues, smoke, etc., good luck, cheers, Sonny.

 

It sounds like what is being described is timing chain rattle, after the tensioners have bled down after sitting. Upon startup, oil pressure must build for the tensioner to take up the slack, which is why it last for such a short burst of time, and only on cold starts after sitting.

 

Maybe on earlier cars, but not on late twin cam cars, cheers, Sonny.

 

Thks for everyones help/thoughts.

 

It can be very noticeable on 996/986 at times, after sitting, which are all twin cam cars.

 

following break in probably f.ked it up.... drive it after it reaches engine oil temp. run that redline

 

The chain tensioner on a 996 will sound just like that when loose, but this is a new 997gt3, might be something else.

 

There are good threads on this at Rennlist.

I tested 5 tt's before I bought mine and they all did it.

Apparently it's the intermidiate shaft that is a little sloppy at low rpm.

The best fix is to get an exhaust that's loud at idle.

tw

 

hahah....me too!