PeachParts Mercedes-Benz Forum - View Single Post

eatont9999 · #14 07-16-2012, 10:30 AM

Quote:

Originally Posted by mikeyfev1

Eaton,

Amazing timing, I did the same thing (5 injectors in a 1985 617, installing Monark needles); finished last weekend.

I have some observations about differences in what we did:

I did not lap the top of the new needle housing. I figured that if the factory can't get these machined flat, I certainly can't do better by hand.
I did not clean the shipping lubrication from the new needles/housing.
The parts inside my injectors did not look the same as yours. The part that goes between the spring and the intermediate disk (some diagrams call this the "push rod" or "thrust pin") looked quite a bit different. This is the part that in your videos you referred to as "I don't know what this is called".

The first 100 miles or so seemed very smooth. Ever since then I've noticed some knocking at around 1500 RPM. I've read from older posts that it will take a while for everything to sort out after this change.

Your methods are probably just fine. Lapping the needle housing is probably a good idea but it does look pretty smooth. Removing the shipping oil is not necessary in my opinion but I followed the procedure laid out by the vendor to ensure I didn't void my warranty. I'm not sure of the differences between 83 and 85 617s but they may have revised some of the injector internals that year. Did you happen to take a picture of the push rod in your injectors?