red60R

My 07 ML is approaching 116k miles, no significant engine issues. That said, there have been more than enough posts on several other areas of the forum (mainly C63), with the M156 engine, having engine failures due to Headbolt issues in the pre 2011 models.

I don't know if anyone has ever done a poll to see how many, have actually had this issue, so I figured I would try one out here on the ML side of the house. IF you have had this issue, could you write in with when, mileage, symptoms, cost to repair/outcome?

My AMG tech says it's extremely rare but I would love to know how many have actually had this issue.

ML63 AMG

89k still going strong. I have heard that supposedly a part of the head lot issue can actually be corrosion related by usi green style antifreeze coolants instead of the recommended official factory coolant (blue). This can cause weaknesses in the head which then causes the bolts to fail (certain of the bolts are "wet" meaning they go through coolant pockets and this is where they usually fail.)

That is the best understanding I have of the problem. Perhaps others can chime in. As long as you take care of her you should be good.

red60R

So really no one among the M156 ML brethren have suffered this fate like some of the C class engines have? I'm surprised. My local tech did tell me that he has not seen any and his master tech has only seen one in almost 10yrs of dealership work.

Solo wing

What I find odd is that most affected M156 engines are found in the C63 W204. I only saw a handful of early W211 E63, ML63 with this issue.
Moreover, North American AMGs were the most affected. Both Europe and GCC spec AMGs didn't suffer that fate. At least not the the extent of North American AMGs.