2001 Honda CRV Cold engine clunking noise under car when AC

Hi bluepete,

Noise is difficult to diagnose without the physical car but the symptom of the noise being different when vehicle is warmwd up indicates it should not be related to the trailing arms.

It should be engine related and for a vehicle with the mileage and age, the catalytic converter is one of the possible causes.

When engine is cold, try banging the catalytic connverter to check if there are any clanking noise emitted from it. Quite often when internal parts of the catalytic converter deteriorates, they tend to vibrate and emit clanking noises and temperature increase would reduce the noise due to the expansion.