S'up Bigpete123

I have a 1991 300CE myself(bought a few weeks ago at 140k miles) and am experiencing the same problem - a rough shake (bump/cough) during idle. I'll keep my eye on the oil pressure during a stop light and will see it drop slightly for a second and get the "bump" that you described. The problem doesn't come up until after driving around for a while.

Recently, my mechanic has swapped out the Ignition coil and it has helped tremendously, but the problem still comes up here and there. I'm gonna give him a call tomorrow and bring it in to him during the weekend.

Keep me posted and I'll do the same.