I changed the spark plugs on the car about 5 months ago, and ever since then there has been a sort of clicking sound when revving my engine, particurarly in 1, 2, and 3 gear, when in forth, it seems fine. It also does not do this all the time. If I loosen the bolts on the engine cover, it seems to decrease this sound, or if it is really cold out, it seems to as well, or just the sound maybe decreased. It doesn't hesitate, it still runs fine, but I want to know what this sound is, because I like my engine to sound perfect. lol. any ideas???

 

Sounds like your firing order may be wrong. When you changed your plugs did you disconnect all the wires or did you do each plug and wire one at a time?

 

actually figured it out (well, midas did) 2 of my spark plugs were not tight. I'm a moron!

 

I also think the firing order is not perfect.