M156 head bolt problems
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From: Canada
07 E63 + 07 CLK63CAB
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?
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Scooter
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.
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From: Battle Ground WA
C63AMG, NIssan NX2000, Pontiac Fiero GT
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?
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?
Last edited by motoman; May 22, 2013 at 05:01 PM. Reason: "improved" oem headbolts?
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From: Canada
07 E63 + 07 CLK63CAB
@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?
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C63 AMG
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.
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.
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C63 AMG
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.
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.
Last edited by Merc63; May 23, 2013 at 01:58 AM.
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2009 C63
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Regards,
Joe
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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..
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From: Battle Ground WA
C63AMG, NIssan NX2000, Pontiac Fiero GT
Moto, it's too much to write on here. If you don't have a very very good grasp of mechanics and supply of tools I would leave it to the pros.
The cams have to be removed. You need a special mb tool that holds the cams in place to put them back. Also one cam needs another special tool to hold it with the adjuster, the other cams you can use a bolt that threads into both gears.
Once you remove the cams and put them back in, it's quite simple. It's just getting over that first hurdle.
It took us 2 days to replace all the bolts with studs. No way would I use the new mb bolts.m if your going that far use the studs and do it right.
The cams have to be removed. You need a special mb tool that holds the cams in place to put them back. Also one cam needs another special tool to hold it with the adjuster, the other cams you can use a bolt that threads into both gears.
Once you remove the cams and put them back in, it's quite simple. It's just getting over that first hurdle.
It took us 2 days to replace all the bolts with studs. No way would I use the new mb bolts.m if your going that far use the studs and do it right.
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From: Oakville, Ontario
2011 c63
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Junior Member
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From: Oakville, Ontario
2011 c63
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?
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?
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From: Oakville, Ontario
2011 c63
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?
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?
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From: Battle Ground WA
C63AMG, NIssan NX2000, Pontiac Fiero GT
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
I know you are kidding and are getting closer to writing a procedure . motoman
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From: Richmond Hill - Markham area, Toronto, Canada
c63, prius
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.
as of today, my advisor told me that the cylinder head was remove and getting ready to be reinstalling back.
