Originally Posted by morganb

The heads have been off and X-rayed looking for porosity, nothing found and they were all perfectly flat.
The Block is now going for the same treatment. Hopefully will know something on Friday or Monday.
To summarize: 2 cylinders no compression due to valves not sealing, one broken head bolt (not bad leak), and water in 3 cylinders not related to the head bolt. As yet it seems no reason found yet as to what would have caused all this. The scary thing is until 2 minutes earlier the car was running great with no warning lights. Then low water warnings and about 30 seconds running time later the CEL came on and the car was running rough and putting out a smoke screen the Batmobile would have been proud of.

Originally Posted by morganb

Well they cannot find anything wrong! The water on one side in the cylinders seems seems to have magically appeared there! They are sending out the head assembly with a new set of head gaskets to be bolted to the block (still out of the car) and then pressurizing the cooling water ways to look for leaks! I have never heard of this before with a motor out. Any comments from technical experts would be most welcome.
Now 5 weeks and still do not have a cause. This is becoming very frustrating.

Originally Posted by morganb

The Service Supervisor just told me that with the heads on and the water system pressurized then water is coming up through the head bolts. At this stage these are still the old head bolts. I am not quite sure how this would let water get into the engine Would there should still be gasket between the head bolt and the combustion chamber? Water was found in both banks of cylinders. This also happened very quickly with the low coolant light to massive amounts of smoke and running really rough over about 45 seconds to 1 minute of car running time. This seems to me to be something that would happen slowly. Next they plan to put new head bolts in (in Australia they also have the note to use the "new" head bolts) and pressurise the coolant system again and see if the water is still coming up through the head bolts. Any suggestions or comments appreciated.

Originally Posted by 2008AMG63

Does this apply the same for E63 engines? Or there are many differences even using the same type of engine?

Originally Posted by DuaneC63

It applies to all M156 engine numbers up to 569xx 60 060658 regardless of what chassis the engine is in.

Originally Posted by Pickles

So, what year/model do those numbers equate to, & does that mean that all engines manufactured after that date have the "New" headbolts, as a consequence of which are unlikely to suffer from this problem?
Cheers, Pickles.

Originally Posted by bhamg

There's been nothing definitive stated about how the last engine number of that range equates to the build date, but it seems to be fall somewhere in the first half of 2010. Yes, the new-style head bolts are used on the later motors. Presumably they will solve the problem we are seeing with the old style bolt.

Originally Posted by C63sydney

Woops sorry...

Was not aware of this, makes sense tho... Just trying to help the database.

Originally Posted by DuaneC63

There is a head gasket between the deck of each bank of cylinders and the heads. The gaskets seal the combustion chambers and allow coolant and oil to pass between the heads and the block while keeping everything separate. The head bolts on the M156 motor are torque to yield. Each head bolt achieves a specified clamping pressure by being tightened to a specific torque then turned an additional specific number of degrees. All this is done by a robot to get uniform results. The upper section of the bolts are designed to stretch slightly to achieve the specified clamping pressure. It appears that the design of the head bolts (or perhaps the metallurgy) was incorrect. This fault in the design allows the head bolt(s) to stretch further (and in some cases snap). The failure of one head bolt puts additional stress on the other bolts causing additional failures. The loss of clamping pressure allows coolant and oil into the combustion chamber. (Coolant can also be forced up through the failed head bolt locations into the top of the heads.) This is what caused all the smoke and rough idle. In severe cases this will cause hydro lock in one or more of the cylinders, causing the piston(s) to seize and destroying the entire motor. By pressure testing the cooling system, your dealer has determined that the head bolts have failed allowing coolant into the cylinders. MBZ has a revised head bolt design as detailed in a service bulletin. The repair involves removing the heads and checking each piston at top dead center to see if the con rod is not bent. New head gaskets, new revised head bolts and new revised lifters (another issue) are then used when the heads are re-installed. Due to the design of the twin overhead cams in the M156 motor this is a complicated and very time consuming repair. Hopefully you are still under warranty.

Originally Posted by morganb

Outside of the car the heads have been put back on the engine block, New head bolts installed, another set of new gaskets and now no water comes out of the head bolts when the cooling system is pressurized.
Seems the old style head bolts are the issue.
Next Step- The Dealer is applying to MB Aust to request them to cover 100% of the repairs. I am sure I have a good case with all the background that some of you have helped me with. Thanks to all those who contributed.

If MB reject the application to cover the repairs I will need to determine how to proceed as it seems there is defintely a fault with the bolts that MB is aware of and possibly should have addressed earlier.

Bruce

Originally Posted by DuaneC63

Bruce,
Did they install the new M159 lifters while the engine was apart? It's part of the service bulletin. I know of at least one out of warranty member that got the cost split 75% MBZ 25% owner. While that is not a great result, it beats a sharp stick in the eye. I don't know if they have small claims court in AUS, but its very consumer friendly over here.

Originally Posted by morganb

Good Point, I will ask. Its not back in car yet so hoping it can be done as part of the install.

Originally Posted by SonnyakaPig

Duane,

I was just reading your post that I'm quoting while I was eating at a restaurant. I notice a man walk in that had just parked an SL63. So, as I'm walking out I say "nice car." He responds, "yeah, MB makes great cars." I asked, "have you heard about the head bolt issue?" He answers, "yeah, my SL broke a head bolt when it had 5,000 miles on it." He said they had to replace all the bolts and "shave" the head. Dealer told him the work, if it wasn't covered under warranty, would have been 16K. His car is on 09'. He said he noticed the car had an issue because of the coolant loss indicator light in the dash.

Originally Posted by betrezra

Does this also apply to CLK63 Black-series?

Originally Posted by m a x i m u s

does anyone know about when this problem started to come about, and when did MB start making the repair with the new bolts? reason why i ask is i am looking at a carfax on an 09, and it shows that the head gasket was replaced in 7/2011. wondering if there was a chance that the new bolts were used as a replacement when putting the head back on...