My car is idling kind of loud.It is worse when the engine is cold.At first l was afraid it may be knocking, but when l rev the engine, it makes a nice smooth sound.l do not even know how to describe the noise--it is not a knock (l dont think so anyway), l wouldnt describe it as a tick or a ping...It almost sounds like what l think are normal engine noises--except louder than it should be.

Any ideas on what could be going on?

These cars have a pretty sophisticated engine management system so code reading it would be a good start.If the idle speed is wrong it can make the engine sound off,the cold may make it worse.Sorry,vague question ,vague answer.Get it code read.

The most common noise that u will hear under those conditions is the heat shields from the engine exhaust system rattling. there r metal heat shields on the front of the engine over the exhaust manifold as well as shield under the car around the catalytic converter. over time these shields rust or break the welds that hold the shields in place. when that heppens then they rattle & give u the ticking noise. as u increase the engine speed the frequency of the vibration increases so that it ''goes away''. also, as engine temperature increases the metal shieds expand & u have greater clearances to the noise goes away.

have the exhaust shield checked. l think that is where u will find the problem to be. its not a harmful condition, only annoying.

(this assumes the oil level in the car is full & that the valves r properly adjusted.)

hope that helps