Well, I finally did it. I replaced my noisy clattery timing chain today on my 92 400E. I did it with the assistance of my mechanic. We worked on it strait from 9:30 am to 9:00 P.M.
My MB mechanic has never done one on the quad cam V8, so it was a learning experience for both of us. When actually feeding the chain in, you really need 3 people. One to crank, one to feed the new chain in and pull the old, and the 3rd to manually spin the exhaust cam on the pass side (it isnt being pulled by the chain once u break the original chain in half).
The chain constantly wants to jump everytime one of the cams springs. We had to make a couple tools to hold the chain from jumping. It took over an hour to manually feed it through. To replace the tensioner, you have to lower the airpump.
And beware, getting the cam covers off is a job in itself. You need a special swivel allen socket to get to both back bolts near the firewall. MB definetely shoehorned this motor in there. The motor is alot quieter now, it has gotten rid of the strange cyclic noise that it used to make, not to mention piece of mind.
Total cost was around $250 for parts (chain, tensioner, upper rails (in between cams). Labor was $240. Total: $490. Not too bad. We inspected the other rails, and all seemed fine. Also of note, the plastic oil tubes that are known to crack on these engines and create a ticking noise, well, mine are definetely aluminum. Was this an aftermarket part? Or maybe an updated part? I could of swore they were quoted to be plastic and brittle. I even took one out to check it. Its metal.
DIY, I would think twice about tackling this on your own. Its VERY involved. I dont think my mechanic is ever gonna touch a M119 ever again haha.
I love my car