my 3.8l engine is making a knocking noise at idle when the engine is cold. When i hit the gas or once it warms up the noise goes away but then when i turn on the A/C the knocking noise returns. My oil level is fine. Any ideas?

 

Where do you want to start... theres a couple hundred things it 'could' be.

low oil pressure
bad water pump
cracked flex plate
crank pulley
tensionser pulley
idler pulley
alternator bearings
a/c compressor
rocker arms
cracked piston
worn rod bearings
worn main bearings
worn cam bearings
timing chaing
lifters
could even be the Canister Purge valve

 

hey thanks for nothing! i was just wondering if this was a common issue and maybe someone had it happen to them before and could lead me in the right direction. Thats the point of a forum right? not to tell people "well it could every part of your engine"

 

The whole prob with noise is that U cant hear it over the internet what some thing sounds like to u maybe different to an expert understand?
Anything that moves can make noise.

 

WHAAAAAA my car is broke WTF is wrong and why don't you fix it for me!!! I demand you GIVE the correct answer... NOW

geez... some people

 

loose nut behind the wheel?????

 

I knwo the post is old was it the famous flywhell problem? I thought it was my a/c compressor and changed it for nothing. Turn out my 2nd guess was right fly wheel