roadtalontsi

So i recently did some head studs in my car. I went ahead and pulled the motor so i could rebuild the transmission and since i have long tubes i did it out the bottom. Here'ss some pics to give you an idea of what is involved. Keep in mind my bolts hadn't failed yet, but considering the blower and the way my wife drives it's just a good idea. So i took it all apart first before i decided i was going to take a bunk of pics to show whats involved. Some steps are left out, you'll need special tools to do this job so if you're questioning your abilities forget about it. These motors and the parts are stupid expensive if you break something or do it wrong. pics from transmission rebuild can be found here.

https://mbworld.org/forums/c63-amg-w...ngagement.html


So i can only post so many pics in each post so there will be a few.
first up in order.....

My engine has about 30k on it, most of which with the oil separator too, these motors carbon up quickly regardless of how much you get on it. Here's what the cylinder head looked like.

My engine mounts were slightly collapsed, so might aswell replace them. here's new vs old.

this is the difference in the original stock, updated stock and arp weistec studs

here is what the pistons cleaned up to. loctite 7200 cleaner and plastic razor blades work great.

here is how the pistons started.

roadtalontsi

heres the head cleaned.

studs installed

This is how you remove and install the guide pin for the timing chain idler gear in the cylinder head - there is also a bolt that holds these in

cams are installed and lubed up, new lifters or hydrualic compensation elements as some would say - when removing make sure you label all the camshaft journals they are not marked from the factory.

cams are installed with the holding device - note the black bar in the back and the black fork tool across the front on top

this is the slide hammer and adapters needed to remove the chain idler pulley pin and chain guide rail pins

roadtalontsi

camshaft adjuster loose

camshaft adjuster tensioned with special tool - earlier styles can just use a bolt in the back when removing to lock in place

this is the inside of the camshaft adjuster with the special diamond plated friction washers laying out to the right. make sure you replace them, these and the camshaft bolts are the only thing that hold the adjusters to the camshafts there aren't any dowel pins to key them

adjuster installed

right bank pulse wheels aligned ready to torque down

left bank pulse wheels aligned ready to be torque down

roadtalontsi

this is what the camshaft pulse wheels look like when aligned properly and the tool is off for reference

left bank

right bank

valve cover, make sure to replace the outside gasket and inside 4 spark plug hole gaskets

weistec valve body upgrade

and the motor is back in, not running yet but soon.

mr747

good job mate looks like you have been busy

subscribed
thanks for taking the time to take pics
im glad you know what you are doing

Jasonoff

Did you happen to take a pic of all the old head bolts?

How did they all look? Were there any worse off than others? If so what position were they?

Mort

Thanks again for bringing this mechanical/technical information to the forum. The pictures are enlightening.

The bottom of the head in your first picture looks a little gnarly. The aluminum seems quite covered in oxidation. The rear cylinder also looks like there is something else going on in the combustion process. The first three have a burning slightly rich carbon look while the fourth has a more lean maybe coolant fouled look.

Oops. After looking at that pic again it sort of appears that the head might have some kind of cleaner sprayed on it?

Ingenieur

thanks
great write up
did any bolts break or deform when removing them?
what positions were the most damaged bolts it

did any of the bolts cause you concern due to their condition?

old style vs. new
are the flared shanks at the top the same size?
are the flanges the same size?

Critter

Yes for sure that first pic of the head looks like a crap load of aluminum oxidation, definitely resurface that head before putting it back on the engine or the seal will surely be compromised. Take same amount off second head to ensure equal compression and volume on both heads. I know u know, just saying.
If coolant leakage has been occurring in that cyl the it would be prudent to replace that piston if you are going for a high output engine.
Possibly Ingenieur could chime in on crystallization of the piston top.


Good job though, brings new insight into the upgraded head bolt issue. As well as the feature of the diamond plated friction washers, just wonder what the thought was by the designers of this engine by using this method instead of keyed, grooved, taper or interference fit to name a few, somehow although it seems to work there is always chance for slippage if the bolt torque is inadequate.

Jasonoff

Looks like a foam cleaner was spayed on...

Ingenieur

looks like some of the bolt holes are fitted with locating dowels to prevent lateral movement
but 12 bolts torqued to 100 lb ft or so should provide adequate clamping force
almost all force is outwards

abcut973

Thanks for sharing this recent install/clean up. Very instructive

Critter

Yes Jasonoff on second and third look I think you are correct .

Mort

I took a second look and already edited my post as well.

Jon2007E63P30

Excellent write up, thanks for taking the time to take the pictures.

roadtalontsi

no broken bolts, none broke on removal either, or deformed. I honestly didnt keep track of which cylinder each bolt came from. Id say about 6 bolts looked pretty ugly and substantially worse than others, with definite signs of heavy corrosion that would cause future problems down the road. It's really dumb they just sit in the coolant jackets, and they aren't coated with anything special to protect them. Ill measure the shanks tomorrow i'm sure they are the same size. The weistec's dont have the shank and have you use silicon to insure proper seal. I almost want to say the flange on the newer style bolts is smaller, but ill check tomorrow.

Yes sorry that picture has the foam loctite 7200 cleaner sprayed all over it. I think i forgot to take the picture and remembered half way through lol. The rear cylinder 3/4 and 7/8 were the most carbon'd up. Cleaning took more time than the entire job.

Jasonoff

If that's truly the case then this issue should be an official recall.

How many km/miles on your motor?

jvanbrecht

Give up on the recall idea. we would all love it, but it is just not going to happen. It's one of those cost loss analysis type deals, and I suspect they might not learn from GM's mistakes since they are not an American company. They will deal with each engine failure on a 1 by 1 basis, and hopefully cover the cost if you make enough stink (but no guaranty).

Critter

Could you post pictures of all of the replaced bolts, Thanks in Advance.
Did any of the have Made In ????? on them

Jasonoff

Let me clarify. "If" all the bolts will eventually fail MB will get flooded with repairs and will have to do something about it.

I.E. full repair covered "if" it happens sort of thing.

Ingenieur

thank you
very informative

roadtalontsi

Most of you live in this fear of a bolt breaking. Truth of the matter is just complain about low coolant light coming on. Even if you are out of warranty they'll offer you assistance. Just tell them you know about the tsb. Sure you will probably be somewhat out of pocket but if you are a good loyal client they'll probably goodwill the entire repair.

Recall will never happen. alot of 272 and 273 motors had bad balance shaft gear, or timing chain idler problems with the teeth wearing off them. this didnt affect a few/small run of amg engines. It affected like 100,000 or so motors. No recall, just a bulletin. They get goodwill'd or extra assistance from mb unless you are just a total *** to the dealer.

The hard part ofcourse is finding someone competent to do this job properly.

motoman

Good pictures. The evidence mounts that the coolant- jacket headbolts are a bad design. Someone more skilled than me should compile a complete picture- set of the removed headbolts with the red and white rust just under the bolt heads. That could be added to the sticky. Yes, no protection on the headbolts is true. Zinc in all forms is very anemic faced with high temp and low pH coolant (according to experts). The coating on the new headbolt is very thin and the one I sectioned was already nicked many places inside the new bag. Under magnification it also looked like more than one bolt was abraded on the "dowel" during torquing, removing the zinc. Again, let's try to document the pattern of broken bolts. It would be interesting to have heat sensors around the head, not just the "average" heat to the temp gauge, which is ?probably? reading the water pump coolant temp.

motoman

We have posted the German sources (3). Earlier I suspected defects, but the (extremely low quantityand therefore suspect)samples I looked at seemed fit at 10x. Not even ARP nickel based studs can withstand worst case corrosion. ARP procedure calls for white cotton gloves when handling the studs during install.

Ingenieur

I would be willing to contribute towards some lab tests
Basically destructive testing on several bolts
Torque to yield and fracture/failure
Do the same for a new old style bolt if one can be found
To determine strength reduction
And test a new style

Needs certified by a lab/ engineer
Might be handy if litigation is an option