M103 stuck lifter
 

I believe I have a sticking lifter on my 300CE. When I start the car cold I don't hear anything but as soon as I accelerate I can hear a faint ticking noise until the car start to warm up. In the warmer months it is not as noticeable. I put a bit of Seafoam into the crankcase right before my last oil change and that didn't seem to help at all. I change the oil frequently, usually every 3-4 k miles and I'm using Mobil 1 0W-40 with Mahle or Mann filter. How can I determine which lifter is sticking? I'm assuming it is an easy fix to swap in a new one on the M103?

Would'nt a stuck or sticking lifter give some performance issues? like a feel of a misfire? Stumble perhaps?

You can test by hooking up a mighty vac to the intake. if the needle fluctuates wildly, then you could be right.

Try changing the oil to rotella.

When I had an M103 the mechanic simply removed the valve cover and pressed each lifter to see which one was collapsed. Then he removed that rocker arm and swapped out the old liter for a new one. Parts cost about $10.00 and it took about 15 minutes.