Ratcheting noise from camshaft at 2000 rpms and a smog pump that won't turn off

[MyCarIsWilhelm]

Hello!
I have two issues on my 95 S320. I have just recently had a partial head rebuild on the car with a new head gasket, other gaskets, spark plugs, and oil. The car seems to run smooth with no issues, except for when my camshaft adjuster magnet is plugged in. It makes an awful ratcheting noise at 2000 rpms, then goes away. I though it was bad so i bought a new one but the ratcheting noise came right back once that one had been plugged in.

I'm thinking that the timing could be off but I don't want to jump into fixing that thinking that I can't get it right when that might not even be the problem to begin with. Oh, and the timing cranks over by hand smoothly (not stops along the way).

Is there a possibility that something hooking up to the camshaft adjuster could make this noise or am I wrong?

Also, as soon as my smog pump is plugged in, it doesn't even turn off. It's not even cold here in Sacramento. I think the switch for it needs to be replaced but I'd like to be sure.

Does anyone know an answer or possible answer to these explanations??? Please help!

[97 SL320]

The cam adjuster is just a coil of wire. It sounds like the actual adjuster located on the cam has a assembly issue. I don't have any pics for this.

Do a search on this site for electric air pump, there is a relay somewhere that controls this.

[MyCarIsWilhelm]

How does the adjuster on camshaft get fixed or how do I know for sure?

[97 SL320]

Another thought would be that the timing chain isn't tensioned due to a bad guide or tensioner.

The cam adjuster only moves one cam changing how "smoothy" it rotates. Cams are notchy as lobes open the valves, sometimes one lobe is opening and one is closing canceling each other out. When the cam to cam timing changes the notchy level changes.

Timing chain noise also requires a certain RPM to get the chain to whip / try to climb the slack side of the gear.