I recently noticed that there is a low ticking sound coming from the engine after I turn off the car after a 20+ min drive. It's not anything that is very noticeable until you put your ear around the intake manifold and listen for it. The ticking sound also isn't continuous, instead having a 5+ second pause in between ticks.

I'm not sure how long it's been like this but the only thing I've done that comes to mind as to might be a cause is the installation of a cone filter in place of the stock airbox 2 months ago. I'm hoping it has nothing to do with dirt getting into the cylinder. I'm also overdue for a timing belt change by about 3K miles but I'm not sure that's suppose to be a sign to change it (or is it?).

 

That's the bomb that will detonate at any time, so don't go near it...

 

lol a bomb? hmmm ya ok
that sound will come from any car after its been on for more than 10 or so minutes. all it is, is the hot metal( your motor and exhaust and stuff) starts to cool, and makes that kind of light light tick sound

 

what black92SE said.. it's not big deal. it's just the exhaust cooling down. happens on every car.

 

phew... here I was thinking it was another noise I had to fix

thanks for the responses