I noticed this summer that whenever I start my car in my underground garage... well, if I rev up the engine while it's still a little cold I hear these "popping" sounds coming from the engine at around 3000 rpms...

I've asked around and most people say it's normal it's just condensation... but I just wanna be sure...

My scenario is: Rev to 3000, the second it hits lets say 2900 on its way down it pops once or twice, not like a loud pop, but a... crap hard to explain... then it goes down... you know what I mean.... Any comments?

 

Just wondering how long you wait to go revvin it like that?? we talkin like 5secs after startup or like a minute?

 

like a minute or two...

after 5-10 minutes it stops making the sound...



also might i add my car makes the weirdest sound when i'm decellerating, sounds like i have a custom exhaust.

if i downshift and i'm slowing down you hear this weird backpressure sound, no popping or anything, but it's loud as hell, lol

 

possible exhaust leak sucking in cold air...until the pipe heats up and expands..thus closing up small leak....hey i dont know its a guess....lol

 

You might want to check the timing and the condition of the distributer bearings, that can cause the timing to wander and that will cause popping, but it can do it at any temperature.

Alternatively if you rev up too much when the engine is cold, depending on the model type, the older throttle bodies push in lots of gas at start up and it could be ingniting in the exhaust.