DCW

Hello, first time poster here. Just purchased a 2012 E350 Bluetec with 144K miles on it knowing it had a timing chain noise on start-up. It would quiet down after a few seconds. I replaced the tensioner to see if I could get lucky, but that made it worse. So now I am planning on pulling in a new chain following the excellent write up https://mbworld.org/forums/diesel-fo...0-blutech.html. I done a few other cars in my past, most recently a Saab 900S turbo, but it was a complete replacement of all the sprockets, guides and not using old chain to pull in new one. After doing a lot of searching, I still have a few questions I'm hoping someone with experience can help me with.

With this kind of mileage, should I plan on also replacing guides? I assume I would have to remove both valve covers and take off the front cover of the engine? Or should I just try pulling in a new chain and see what I end up with?

Also, in the referenced post, it shows using a pry bar to keep the chain from coming off the sprocket. An internet search found the below tools, but I don't see how the sprocket tool mounts to anything to hold the chain on. I'm thinking the cam hold down plates are probably a good idea to keep the middle valve spring pressures from breaking the cams?

Thanks to anyone who has some valuable experience to share.
DCW


cam sprocket chain tool

cam hold down tool

DCW

I think I found the answer to one of my questions. I believe the sprocket tool lays horizontally 180 deg rotated from the above picture, and bolts to the top of the head. Therefore the tool guides both sides of the sprocket and the chain will extend out of the top.

kajtek1

Haven't hear about those engines eating chain guides.
Not direct comparison, but few years back I was replacing oil pump on OM603 engine with close to 300k miles.
Timing chain was not on my list, but I took close look at guides and inspected them good enough to put back.

DCW

That sounds promising. Unlike some engines I've dealt with, like the SAAB, I haven't read any posts talking about guides breaking in two or being worn so bad they needed replacing. I'm planning on just replacing the chain unless others chime in with different stories. Thanks for info