PeachParts Mercedes-Benz Forum - View Single Post - How to tell if M103 cam modification was done

ps2cho · #4 11-07-2010, 01:58 PM

You can't buy the updated cam with the old style rockers unfortunately. It is an entire swap.

Early rockers that need to be replaced:
103 050 02 33

Updated rockers:
103 050 10 33

Early cam that needs to be replaced
103 050 51 01 or 103 050 52 01

Updated cam:
103 050 64 01

This is why unless it was done early during warranty, it is high unlikely they were replaced. Based on your issues, I doubt they are the updated models. That scoring looks like what I have seen on the early style. Like I said earlier, expensive yes and it sucks, but once replaced your top end will last 500k miles albeit a few more valve seals and a couple head gaskets of course.

Make sure regardless going forward you are using 15-40 Diesel grade oil such as Rotella-T 15-40, Mobil1 Delvac 15-40 etc.... That is part of the reason why this scoring occurs due to modern oils not having the correct zinc additive package that these engines require. It will also keep your valvetrain super clean.

If you can't afford it now, I recommend going to the junkyard and grabbing another OLD style camshaft and rocker and temporarily solve your issues until you can fix it for the long haul.