CL55_Serge

I got the car w/ under 25k miles on it, every time the cars sit for a bit or it's cold outside, I hear what sounds like slight rod knock or a noisy valve in the head type noise (4-7 iterations in a row) on startup which goes away quickly. The folks at the dealer tell me that the M273 motor is very noisy on startup and that there a number of bulletins issued that describe the noisy operation as "ok" - do you guys all hear the same noises on startup?

My CL55 which is based on the M113 never makes much noise on startup, maybe just a little valve lash on a very cold day and it's very quiet. I'm suspicious something might be wrong...