07 lx and when ever i turn on the power for the heat to work i hear this Clunk noise from the engine bay. is it haw they just turn on ?

 

Every car I've had makes some sort of noise when turning on the A/C or heater. A clunk, a whir, a hum, etc. I don't know what you consider a "clunk", but I'm pretty sure it's just the heater and/or fan turning on.

 

Let the car run for a bit before turning on the heat or AC.

 

A/C clutch always makes kind of a clunk noise when it engages