this is caused from piston to cyl wall clearance when engine warms up the pistons exspand and the noise is less. DON'T WORRY ABOUT IT
belt
Is it a lifter ticking?
why won't a 2001 Impala shift into high after it warms up? All shift sensors have been replaced
You have to locate the source of the noise then repost your findings.
The fluid could be low, or the pump could be weak and makes noise until it warms up the fluid. There is an additive available to help quiet the pump.
Wait until it warms up and melts
It is possible that the bearings are going bad on the water pump but you are going to have to listen to where the noise is coming from, whether it is inside the engine ( rod knock or oil pressure issues ) or outside (pump bearings or pulley issues).I lean toward internal wear or damage to the engine since the noise goes away when it warms up which indicates that when good oil circulation is present the problem goes away, bad bearings in a water pump will always make noise until they are repaired.
Cold air is more dense air so for a given volume of air more fuel will be used. Also, when the engine is cold it tends to run richer (more fuel) and higher idle until it warms up.
why is there squeek noise when starting and then goes away when engine warms up
It will until the coolant warms up.
If the noise on occurs after the vehicle has sat for a while, it could be a hydralic valve lifter bleeding off. They tend to click for a while until the oil pushes all of tha air out. Maybe go to a lighter weight of oil. BG makes a product called MOA that has helped ease the clicking noise in vehicles I have worked on in the past. Take it easy until it warms up and even clicking it should last for a whole lot more miles!
Chev has a law suit on their small blocks from piston slap. Take your vehicle to a real DEALER and have them check the recal against your VIN #. This is a big problem for Chevy... the pistons are cam ground (not round) and expand to a circle in the bore as she warms up. The noise I suspect you are hearing is the famous piston slap that these units are getting known for. Go on some Cheby forums and I am sure you will find discussions on this issue. Hope that helps you --