dunno if this is normal but if i dont drive the car for a while then i turn it on to warm her up, i hear a knocking, then after it goes away...should i get this looked at?? thanks.

 

mine does it too.. your not the only one

No idea what it is.. but I dont like it.

 

Does it knock like 3-4 times and does it sound like it's coming from the back of the car? If so, that's one of the sensors making that noise. It's normal. There was a thread posted about that too. It happens to everyone.

 

not too sure if it sounds like its comin from the back of the car, but it only does it in the morning or if i havnt driven it for a while, other than that nothing... wierd.

 

ohh wait i know what knock yer talking about, i know about that one lol

 

I noticed that my car did that when it was below 20 degrees and i started it in the morning.....it made a knocking sound for about 2 seconds and then went away...this knocking was definitely coming from the motor

 

Oh well then that's not good. I haven't heard that noise coming from the motor. But then again, the ecotecs are very noisey motors to begin with.

 

soemtimes after a cold start it knocks then goes away then knocks then goes away then is totally gone after the warm up.

 

Its your timing chain tensioner....or so I was told by my dealership. Since it is spring loaded until oil pressure builds they told me it was common to knock on cold starts for a few seconds. It "shouldn't" hurt anything. They replaced mine and it still does it. GM is aware of this and said it was "normal, replace if customer requested".

We'll see if there is any long-term damage.

 

hmm interesting, thanks bud.

 

Further with a DOHC motor, you have almost 2X as many valvetrain parts moving than a simple pushrod motor. It is bound to make some noise....or so I keep telling myself

I know that my GP with the 3.8l S/C pushrod motor doesn't make any noises on cold start-up (and it is pretty heavily modded too), like my 2.4L VVT does. It sure takes some getting used to.