Random rough idle after chain & guide swap W126
 

Well, my "free" grey market '85 380SEL finally got it's (upper) guides, rails & chain swapped. ODO (broken) reads 134K miles, and I can tell someone put in a new chain because the top guides on the left head weren't that discolored, while the lower guide was a deep brown and scored pretty good, as was the rail cover on the right head.

Anyway, post-swap, it's now idling a bit rough sometimes (off idle accel, decel & cruise are smooth as silk), and there's a new transcient ticking under the valve covers that comes and goes. It'll tick for about 6-8 on side, then tick on the other side, then be quiet, then tick again. The only other thing I did was put a new rotor in, and by the looks of things new plugs and wires are called for.

Granted, I didn't run the motor a whole lot when I bought it (I think I drove it 2 miles before the swap) but it never idled roughly.

Should I just a tank of gas through it and shake the bugs out or could this be something more? (it did sit for 2 years, and got a new tank strainer, pump, filter & hoses)