My '95 seems to take a really long time to quieten down in the mornings, especially when it's cool out. If I have to get on it a bit, it'll be noisey, but will be quiet after that. Otherwise, it takes forever... and this is in stop and go traffic that heats it on up. This isn't knocking or pinging, just a rather noisey, trademark-LT1 valvetrain noise above 2k that's not really an issue in hot weather.

Could this be the oil pump or...? I'm going to switch from 10W to 5W next oil change but am wondering about this anyway. Would you consider this normal?

103k miles but very smooth and strong otherwise. I just don't want a pump or something to go out on me while I had signs beforehand and missed them.

 

Could be an exhaust leak...my car was doing basically exactly what you describe and I found the drivers side header bolts were backing out. I've had exhaust leaks that I was convinced were bad lifters. Anyways, I replaced the gasket and installed some Breslin bolts last week. They appear to be very nice pieces and are easy to work with...we'll see how they hold, but I expect great things from them! Good luck!

 

I'll check 'em b/c I'm running a bit rich at part throttle too.

 

Exactly what oil and filter are you running?

 

Havoline 10W-30, Napa Gold (Wix)

 

Sounds a little like piston slap to me ... the LT-1 is known to have quite a bit of piston slap when it's cold.

Mine does it, my brothers '97z does it, my friends '97 SS also does it. I just keep the RPMs below 2500 or so until it warms up.

Thomas.

 

I second that piston slap thing. I have a new engine and when it got cool outside it started to have some piston slap. It goes away when the car warms up. Is it kinda like a rattling noise when u get up around 2500k rpm??