Mercedes Forum - Mercedes Benz Enthusiast Forums - Starter motor CL500 M273 also M273 engines

I've just replaced my starter with a second hand Bosch at £30. I didn't want a new one even at £85 as they all seem to be made in China and the Chinese alternator which the last owner fitted lasted only 19K miles. I tried replacing the reg on it and the Chinese screws were chocolate.

Part number for the original Bosch was 0001107459 (460), Mercedes A0061516001.

It is probably the easiest job I have done, much easier than replacing the alternator. The hardest bits were getting the car up on my car ramps (using a jack), without having the benefit of the hydraulic suspension raising, and removing the 2 underfloor panels and their 20 bolts. After that it was just 2 bolts and 2 nuts and the starter came out easily. I understand that the USA CL500/CL550s with 4WD are more complicated to remove.

Now I am surprised how fast the new (second hand) starter is compared to the old one. I do remember saying, when I bought the car, that the battery may be going as the starter seemed slow. The seller told me it was due to the engine being a V8 (I am used to a V6) and that seemed to make some sense especially as the battery tested (and is) 100%. Anyway 7K miles after purchase, at 114K miles, the starter remained slow but worked until one day it didn't and I had to have the car recovered. The starter took amps but did nothing apart from get warm. No warnings apart from the slowness for 2 years.

Upon inspection the starter brushes were knackered having worn right down and 2 of the 4 had disintegrated completely. An easy repair except that I don't know what caused it (possibly a worn bush) and I already had a replacement with good length brushes.

I've never had a starter motor fail in any other car. I note that the exact same part number is used on the V6 M272 engines where it would have an easier life, maybe it is underpowered for the V8.