Strange noise when the engines cold...

[asdf1234]

I'm goin to the track tonight and me and a friend were talking about different octane ratings. I'm using 87 octane, just because i have no money. When I first start my car and its still cool, if i floor it while i'm driving, before the engine gets warmed up, i hear a strange rattling noise. Is this knocking? Due to low octane gas? Maybe its something else? Or maybe its just because my engine has 148,000 miles on it and i dont think the previous owner took care of it.

[98Camaro3.8]

It's probably just the lifters or other valvetrain ticking. Can you tell about where the noise is coming from?
87 is fine for our engines, there's no point in wasting money on higher octane gas if you're running NA.

[asdf1234]

i cant tell exactly because i cant put my head in the hood while i'm driving, im not sure if it does it when im not in gear, i'll have to check.What are the lifters or other valvetrain? Sounds like its coming from the block.. or at least that general area

[Nathan]

I had a similar problem like that. Ended up being a retainer spring for the pulley's. It was worn so when the car was cold it didnt hold well against the tight belt. After belt loosened from warming up the ticking went away.

[BradC]

You should not floor your car when the engine is cold. The oil is just getting to the top of the cylinders at that point and it is just not good for your car or tranny for that matter ;)