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Had the head bolts preemptively replaced on our new-to-us E63 as soon as we got it. I'm not looking to ignite an internet debate over do it/don't do it, but In case anyone's curious, here's what they looked like after 105k miles: Gratuitous
Thanks for posting! So where exactly do they fail? As they appear to have very good thread penetration. Also what are the five (5) circular washer / spacers in the first picture?
Thanks
Thanks for posting! So where exactly do they fail?
Maybe someone can chime in who has a bolt that's broken?
The dark sections of thread down at the end are, apparently, the parts of them that are exposed to coolant.
Originally Posted by slownrusty
Also what are the five (5) circular washer / spacers in the first picture?
I don't know!
they were in the bag o' old parts, I was just using them to keep the bolts from rolling down the driveway.
Last edited by dinnyin; 09-16-2018 at 08:12 PM.
Reason: someone chimed in
I believe they usually break around the head flange. With the female design, they didn't allow enough material and corrosion around there weakens it further. This is why they changed to a male head. To me most of those bolts look good until you get to the head. You can see the rust is coming down from the top. The threads actually look quite good.
No it isn’t but people are very afraid of failures, so preemptively replace them. I’ve owned three AMGs with this engine without any issues. That isn’t saying that I wouldn’t have though. I’m keeping my fingers crossed!
Bought the car for my wife. The whole model would go to @#$% if it blows up on her.
One of my other cars is an EJ STI. That I'm fine driving until I bust a ringland (or not), and then I'll get built block, forged pistons, etc.
Mine probably didn't need to be replaced, I had the T-50, not the T-60 type bolts. I did my own, had help from the M156 master in UAE. Everything went well except I used the 0' mark on the pulley and had codes, had to remove the cams and get it back to 40' mark and everything went well.
I worked on aircraft years ago, I am not a mech anymore but found the job doable with the right tools. I used 2 cam timing tools, so I was sure nothing moved while I torqued everything down. Only thing I would have done differently would paint a line on the bolts, so I could makes sure I could verify 270' turn after the torque value was met. If you have a garage, a buddy to help you can replace the bolts one at a time. It is not rocket science, but I walked away and watched a video or 2 when I wasn't 100% on the process. When I did the job the second time I was able to remove the cams, and reset timing in about 1 hour per side. I also replaced the intake gasket, pcv line and installed mbh headers while I was there. I think the timing belt on my old RS6 was harder than this job.
Oh, I see. I can’t find a shop in greater Boston area that have done it. Few said that they could do it, but were reluctant saying that it would take a lot of their time, and that was not worth the money as the issue is rare. None instilled confidence in me to order the job. Just driving and trying to not think about the failure- but there is a fear.
'04 E55 (Gone but not forgotten), '13 C63 P31 (RIP), another '13 C63 PP
Originally Posted by slownrusty
Thanks for posting! So where exactly do they fail? As they appear to have very good thread penetration. Also what are the five (5) circular washer / spacers in the first picture?
Thanks
They typically snap, below the base of the bolt flange. If you look at the head bolt sideways, the top resembles a Top Hat, well, just below that Top Hat is where they typically snap.
I am about to do head gaskets on a 09’ E63. I built my E55 . I just wanted see if you had any pointers.
Like the timing thing, 0 & 40 degree mark. What’s the best way to do that? I can just mark everything right?
I am about to do head gaskets on a 09’ E63. I built my E55 . I just wanted see if you had any pointers.
Like the timing thing, 0 & 40 degree mark. What’s the best way to do that? I can just mark everything right?
Use the 40' mark, not 0. You will get cam codes at 0, ask me how I know. They had zero marked, but not a white line on 40' and I didnt see the machined "40" on the pulley. Other than that, I would make a mark on each bolt so you get the proper 270 turn after your torque wrench hit the initial torque. Mark the head and cam timing bolts, just makes it easy to see you have done the other torque value. I removed my radiator, after seeing I couldn't get it done with it in. My cams didn't sow signs of wear, so I left those and the buckets alone.
I am coming to a conclusion that internet over-exaggerated this issue. My bolts came out in near condition. It is 2007 with 68K miles
M156 Head Bolt Replacement on W211 E63 AMG — To Do or Not To Do?
Seriously. There is not reason to post this again after just posting it in another thread.
Get some new material. lol
it’s always the e55 guys who are telling everyone how bullet proof the 55 is, yet everyday I see threads on FB about rebuilding this or removing the engine from the 55s. No issues posting the same bs 50 times about “just rebuild”, “it’s easy”. The 63 guys have 1 thread on the 1 issue on our cars and you have a beef with starting a new thread for helping 63 owners out? Why not go stink up a e55 thread and leave this thread to the 63 owners? I’m tempted to start posting in every e55 thread about how they are garbage, just so you can see how stupid you look.
as far as the timing marks on the M156, you set the mark at 40, then check to make sure you’re timing tools fit the cams. If they don’t (you can be off slightly) then you turn the engine over 360 degrees and check again until the tool fits and your mark on the pulley is lined up like Tasos’s video. At that point you can start pulling the cams off and replacing the bolts. You’ll hit the torque value and add 270 degrees more of a turn. I’m glad someone took the time to make a video, and shared more info on the M156, they are cool engines but MB didn’t really beef them up until later, so the older ones need different oil, and possible head bolt replacement.
09-14-2018, 06:21 PM
