Before it started to get loud, did you notice it when the engine was cold?

Mine might be starting to slap, seems aweful noisy these days at startup...

 

It will be worse the colder it gets as pistons wear some (the "slap" is from pistons rattling in the bore) before they heat up and expand a bit. It is not terminal but it will only louder with time.

 

I hear mine at cold start up, seems to go from a slap to a tick as it gets warmer...pretty much always been there.

 

That's what I was thinking... It will louder during the colder months.

 

well I definetly hear something when it's cold, it's got 20K on it now.
Never made any noises before, just recently started...........****!

 

mine when its cold too, Ticks loud when you come up on a stop sign, and slow down fast. when i stop i can hear it rattiling away. it sounds like **** in the morning!!!

 

Don't feel to bad about it even though GM kinda shafted you on it. I have a old J20 jeep with a AMC 360 that is not used much anymore but it has had piston slap in it when cold for over 10 years now and it is quite notiable at zero and below too but is has not gotten much worse and it is still quiet when warm. It knocks for about a minute or so on cold days. If you are gettng a tick too, it is most likely a lifter.