The M104 inline 6 from ~ 93 to 98 and some V8 motors use the same / similar setup. Have a look online and you will see how it works. The electromagnet pulls a valve at the end of the cam timing adjuster allowing oil to flow ( or be blocked off I don't recall ) the the sprocket moves on a helix relative to the camshaft. A key point is a piston with a helix on the OD and OD.

The electromagnet is just a coil of wire like an AC clutch coil. If it fails it is just like being unplugged. if it gets weak the valve will only open part way when commanded and partially shift cam timing.

The "Cam Adjuster Solenoid" is somewhat a mix of terms and it sounds like they are trying to describe the cam adjuster mech.

I'm thinking the timing chain tensioner ( if oil fed like most are ) is failing and it takes a few seconds to build oil pressure and tension the chain. However I don't know these motors specifically having just gotten a 99 C230 Komp parts car.

There are a few ways to test. After the motor has cooled to room temp, start the engine and let run until the noise goes away then turn off. let sit a min or so then restart, does it still make noise? Maybe even try a few hours sitting. If no noise I'd lean towards the tensioner.

Another way would be to drive car , unplug the fuel pump or relay, let car stall. Let car sit for however it usually takes to get the noise. With fuel still disabled, crank the engine long enough to build oil pressure ( it might not show on the gauge while cranking. ) . en enable fuel then start the engine. If no noise I lean towards the chain tensioner.

For another area to test, try unplugging the Kompressor clutch. There is a drive disc inside the drive that fails causes noise. On these cars the Komp is operated on a cold start to provide exhaust reaction air. When you unplug the cam timing magnet, it could affect engine smoothness enough to get out of the drive disc vibration range. Have a look at Eaton M62 superchargers for what you have, try these sites for some drawings and info CAPA : Eaton Superchargers 3800 Supercharger

If you turn the face of the komp clutch, you can drive the lobes, rock it back and forth and feel for clunking beyond some gear backlash.

Noises and harmonics are sometimes difficult to find.