I wanted to see if any one has experienced this problem before. It only does it when it starts it makes a knocking/rattle noise for a second then immediately goes a way. The car has only 43,000 miles. I'm not really worried as because its a CPO. just wanted to know if this is a problem some of you guys have heard about.

mine used to do that at cold start too... but for some reason it went away.

Mine does it on a cold start and after its at full operating temp. It did 3 times today alone.

mine did that a few times. brought it up at my oil change and they replaced some barrings or something. cant remember was awhile ago

Cam gear rattle, very common problem there's a TSIB to fix, do a search you'll find a ton on it.

Thanks for the replies guys, I will do a search on the cam gear and learn more about the issue.

Yep, I agree. In fact, I've have the same problem...but I've only had it happen to me three times since I've owed the car starting April '11. The car was a lower mileage '06 350 (31k miles when purchased...52k now). The rattle/knock start-up noise only happens to me on hot summer days when the car has sat for 8+ hrs in the work parking lot and when I park on a hill (front pointing uphill). So personally I believe the noise comes from an oiling issue (lack of oil) at start-up. But you should know this...I've read that even those that have had the TSIB done have STILL experienced the noise thereafter, leading me to believe that even if I had mine "fixed" it would still happen down the road. So until it starts doing it on a daily basis I'll pass on the "fix".

My 06 is350 also does it once in a while, especially in the mornings

mine does that starting up right after an oil change.

That's it. It took me 4 years of complaining about this (it only happened occasionally) before the dealer actually heard it themselves 2 months before my warranty was up.

I have the same issue at start up on occasion if the car has been sitting while.

Dealer just serviced my 250 for this issue. Hopefully the issue doesn't comeback. I'm at 44k miles

07 is250, cam gear actuators replaced at 65k. The rattle was random, 2-3 times a week. Never heard it since

happens to me as well randomly. More annoying if anything.