'02 UL w/153k has developed an intermittent "clacking" noise from the engine compartment. It doesn't sound like the suspension but maybe the A/C or suspension compressor. I also hear something when stopped at a light and it takes an extra second or so after the ignition is turned off to stop. Sorry about the vauge explanation. Any thoughts?

 

The clacking noise could be your valves has the car been given the right weight oil during oil changes, has the maintenance been done in a timely manner? My friend did not I put the correct weight oil in his 240 and the valves were clacking like crazy.

 

Cooling fan making noise maybe?

 

Mystery solved. The two bolts that hold the bottom of the radiator to the support brackets had loosened. Replaced and re-torqued, no more noise.

 

I also have 2002 with just over 150,000 miles exactly like thread and the noise I get isn't during any other time except after driving and then turn car off. It's like a ticking type sound but louder coming from engine area but sounds like it's way closer then front of engine by radiator but instead like it's coming from not far from behind the center of the dash area . It sounds exactly like what you have but as I said I hear it after driving for a little while then stoping and turning car off. It goes for a good 30sec to min even after car is turned off . Hard to explain sound but another example I guess would be the sound of your cd changer going through the diff disks but I'm not using my CD player and it's not that just trying to give best sound example I can think of and it's def from behind the dash more. I did tighten rad bolts after reading this post but I still hear it! No one else has ever experienced this ????

 

I had an engine bay noise in my 2002 recently. I found that the 2 10mm bolts holding down the engine cover were squeaky - I could hear them while driving and even when the car was off and parked (thermal expansion/contraction). I gave them a quick spray with white lithium grease and the noise went away.