If you can hear a ticking under the bonnet when the engine is idling, it is probably the IAC Valve, but you don't have to tolerate it - in fact, you definitely should not - the noise you hear is it gradually self destructing, and they are very pricey.
They seem to get gunged up, and the usual symptom is a loud "rattle"; I surmise this is the valve sticking until the solenoid force overcomes the stiction, then it frees and whacks across to the other end of its travel, giving itself a right hammering in the process.
Get an aerosol can of Wynn's Fuel Injection Intake and Carburettor Cleaner. With the engine running, remove the inlet hose to the valve (refer to pages 6E-8 and 6E-9 in the Electronic Fuel Injection Section), and spray about 40 one-second bursts into the inlet of the valve. If the engine appears to be about to stall, wait till it recovers, and continue spraying.
A photo "Where to Spray" is at http://www.suzuki-cappuccino.com/albums/454.jpg
This has cured the problem on several Cappos.