I am having a problem with my 1993 300SE that I can't figure out. Long story short, I was having trouble getting a signal to my camshaft advance solenoid. I found a blown number 4 fuse on my base module. I still get a code 24 on pin 4 when I check the codes which states " left adjustable camshaft timing solenoid (Y49/1), open or short circuit." However, it appears the solenoid is still energizing, because when I reach around 1,500 rpm under load (3,000 not under load), I hear a very loud rattle, like marbles in a can, similar to when a lifter is sticking. When I unplug the solenoid, the noise goes away. Coincidentally, I have a rough idle and the car is running rich (although I don't believe this is solely from the solenoid issue as I also have a code 22, "Oxygen sensor heater, open or short circuit" which almost certainly is contributing to the idle/richness issue. The issue doesn't change when the solenoid is unplugged).

I roughly understand the VVT system, but what could be making this noise when the cam is advanced? I've replaced the solenoid with a new Mercedes part, and also replaced the coil, cap and rotor (all Bosch) and plug wires (Karlyn). So, everything is new.

I noticed the wires going to the solenoid have been replaced (the rest of my harness looks good). Is it possible that these wires are touching each other somewhere? Would this cause the solenoid to operate incorrectly? I checked continuity from the solenoid to where the wires are connected at the repair and there is no break, but I did not yet check across the wires to see if they are touching each other.

Any help is greatly appreciated. I posted this question on another forum and no one will respond. This car is our second/backup family car (I sold a 2011 GLK350 to buy this one because I like the older Mercedes better and find them easier to work on) and I really need to get it repaired. I can drive it with the solenoid unplugged, but obviously this is not a solution.

Thank you!