Karl901

Putting stud in, you had to pull the head.

Merc63

Not true. You can switch to studs one at a time with the head on. I did it myself this wither.

Critter

The studding of a engine seems to be a common upgrade for diesel engines that are running higher fuel loads with higher capacity injectors, higher turbo boost and are producing gobs of HP, 700+ while running higher compression ratios than any AMG ever seen. Searching the web under replacing head bolts one at a time there are plenty of different examples from all over the diesel world doing exactly what we are talking about here. Apparently in a diesel the bolts are stretched under these extreme loadings and blow out the headgasket. Now using basic mechanics it would seem that this procedure could also be used in a Benz, if it was not for the Cams being a PITA to keep in time during disassembly I am sure many of the owners would have already jumped onto the band wagon and either changed out the bolts with new OEM style or just studded their engines with the one at a time method my self included. Any comments?

Mabuhay

So it's safe to say that AMG's from 2011 and up are not affected?

AWD_AMG

For the most part, yes, but no; very early 2011 models are in the affected group.

otakki

It looks like April and May of 2010 is a critical window period.

AWD_AMG

Well the 2011 I found in the affected group showed a delivery date of July 6th 2010, and the door showed a MFG month of 6/2010. The car was roughly 200 below the cutoff, so I'd wager that the change was made in late June, if not early July.

motoman

Thanks for more background. It seems that some on this forum have either observed pros do the work or at least the cam timing work. Perhaps no one has done this job idependently. I know Merc has been helpful, but we lack a rudimentary procedure to help those who would attempt this . I do not have access to star downloads. Seems like a lot of relevant information is available there, e.g., normal torqeuing sequence and values (especially later upgraded oem bolt values). With the suspect block thread sealing (me talking) we need factory chit chat on e.g., chasing block threads or silence, sealing block threads, sealing head bolt washer-flanges. If chasing block threads is required with head on, long , small dia extensions are required. I located a source for the metric chasers. I have looked at Baum Tool catalogue and did not see any tooling for indexing the cams or holding them for chain etc. We need the tool(s) Merc talks about specified. If one is a "make" then someone sketch it up etc. It is frustrating to know the knowledge is out there , but not consolidated. Let's stop dancing.

Edit, I wonder if MB stayed with the same vendor who produced the original failing head bolts. If someone will send me some of each I will look into testing them (forensic lab) and publishing the results. We spend a lot of time theorizing , hand wringing and hopeful waiting (me too). How 'bout some action?

Critter

@Motoman, I am inclined to agree with your edit comment, I had brought this up about the difference being a metallurgical cake mix in the bolts supplied by even a single source supplier. Surely the bolts made in 05,06 for a newly designed engine would not be the same as the bolts supplied for a 08, 09 10 or 11 model year. There must be differences in the chemistry even from batch to batch or in your comment from different source suppliers. Surely AMG engineers did not order all the head bolts for all models years the 63 was to be produced at one time. Are there any insiders from AMG that could comment?

Merc63

Doubt the issue is metal. Its design. Look at the cross section, not enough meat around the head of the bolt with the female torx head.

Id like to write a howto, but really how many guys are going to use it? Maybe motoman and that's it lol. I dont have the time now, winter yes, now toooooo busy.

People should just drive their cars and quit worrying about the head bolts.. If it blows, it blows, nothing you can do about it.

Merc63

http://www.specialtyautotoolrentals....roducts_id=164

Here is one of the tools, you need this to hold the cams for installation back into the head. Without this tool, good luck, they will flop around on you as you tighten the cam buckets.


Below, the tool on the middle right is the one needed to hold ONE of the cam adjusters so the two gears dont move. The other 3 cams, you just use a bolt, a really small one, like 3-4mm and thread it in to hold the gears. Not sure why they didn't make threads on all the cams, but one doesn't have threads, so you need this.

ACEdge

Could you check
WDDGF77X79F224228

Many thanks!

Valvestud

Here you go. Again, All 2009 and earlier, most if not all 2010, and it appears some 2011s as well are affected.

156985 60 035009

Regards,

Joe

Merc63

Look at all the fear we are creating lol. RUN FOR THE HILLS!!

bhamg

You're to blame...one look at your head bolts and my knees started knocking!

DuaneC63

Forewarned if forearmed. At least you won't think it just low on coolant, add some, and keep driving it until it pukes from hydro lock.

Merc63

A little surface rust never hurt anyone lol.

4ramin

Stop the madness people lol, its not a big deal. people act as if this was the only car that ever needed a head gasket replaced. Yes it sucks to pay so much for a car and to find out it has a manufacture problem however, people are so gun shy that every little thing that happens they thing its the bolts. Its really a simple fix to get new head bolts put in. I would not even put the new head bolts in but instead put in a set of ARP head studs and be done with it. Consider the cost a maintenance..

motoman

Merc, If we were closer I would buy a case of beer and bring along a camera and tape recorder. After interviewing you I could show you a diy is not too much to write. Look at the stickys on e.g., brakes and transmission service (in C63 and other threads). Best regards,motoman

jdbassman

Would you be able to check a VIN please?

WDDGF7HB7BF644595

Valvestud

Your engine number is 156985 60 066691 and is outside the affected group.

Regards,

Joe

jdbassman

many thanks for the quick response

Does the manufacturing date of the engine also mean that it does not have the cam lifters problem (based on the class-action issue) or is that independent of the head-bolt issue?

jdbassman

Does anyone know if the engines made post-60658 include the replacement of the M156 valve buckets with the M159 (SLS) buckets?

The early cam lobes are made of a softer material than the buckets and the cams wear the entire time the engine is tapping. The fix is to replace the M156 valve buckets with the M159 (SLS) buckets. Do the post-2011 engines have this fix?

motoman

Merc, (1) thanks for the pic of the tooling-Japanese origin or just the ad? (2)regarding rust...You can not have it both ways. Earlier you said you did not like the rust on your removed headbolts. Now you say a little rust never hurt. I know you are kidding and are getting closer to writing a procedure . motoman

dacatz

first of all thanks joe for check my vin to see if my car is in the effected group..
as of today, my advisor told me that the cylinder head was remove and getting ready to be reinstalling back.