matt543:  the valvetrane
2009-03-27 06:13:22

Paul RN:  It's all the different parts that are cooling at their own rate, and moving against each other. Like when a house creaks at night after the sun goes down.
2009-03-27 06:14:34

martin l:  i don't really get your question here but let me try this. engines make that ticking sound when they are cold because it takes a while for the oil to distribute inside of it, so the metal makes those sounds because the lacking of lubrication.
2009-03-27 06:18:03

JAMES:  The first guy almost got it right... Most ''ticking'' you will hear during a cold start-up is the tappets/or the clearances on the valves. all depends on what type of engine you have. A simple valve adjustment will sort most ticking out. (or new tappets) As for the oil being cold theirs little truth to that... it takes about 2secs to get oil pressure around the engine and if the valves are adjusted right it should take like 5 secs to stop ticking at most. If you have to run it up to temp to stop it then you need some adjustment. Fords have very bad clearance to there valves and most will tick even from near new. Oh and also the ticking is from the very small gap when unadjusted. it ''slaps'' the cam instead of moving with it making a small tick tick tick and will increase with your revs. Edit: sorry didnt see you ment after it was hot, Yes it's your cat cooling down they work by getting super hot and burning excess fuel. then shrink once cooling. give vwparanormal best answer cus his spot on.
2009-03-27 07:23:30

wvparanormal:  Usually the ticking noise is coming from the catalytic converter and the heat shield around the catalytic converter. When the car is running, the catalytic converter heats up to over 800 degrees F. It cools relatively quickly when the car is shut off, but it makes all kinds of ticking and pinging noises as it cools. Speciffically, the metal is contracting as it cools causing the noise.
2009-03-27 08:09:05

bandit_60:  it,s just that the engine is cooling down. they all do it.
2009-03-27 08:20:07

William:  Most likely you are hearing the catalytic converter shrinking after heating up to around 800 degrees and expanding. As the metal cools & shrinks it makes a ticking sound.
2009-03-27 09:31:32