[mmjohnb]

Guys,

I currently have an '02 AMG E55 which I've really enjoyed and the engine (naturally aspirated V8, 349hp) and tranny have been solid. I've had my share of electrical quirks and have had some high repair bills over the years.

I love convertibles and have been thinking about trading in the E55 for an '07-'08 CLK63 convertible. I had the chance to do the AMG tour in Affalterbach last Feb and heard a lot about the naturally aspirated M156 engine and I liked the idea of owning a car that had one in it and I love the idea of a convertible.

However I've read the forums and threads about the headbolt issues that these engines seem prone to and I was curious what others thought lately about this issue (is it real, how likely is it to happen, is it worth spending the money to put in head studs - sounds like around 4K)?

I'm not looking to do any modifications, but I don't want to get into a money trap or look at an engine rebuild if the bolts failed.

Thoughts on the M156 engine and the risk in owning one?

 

[die s-klasse]

I just had this issue on my 2009 CL63 at 76,000 miles.
Coolant loss without any noticeable traces outside.
Dealer drained oil and found traces of coolant.
Took the cylinder heads out and found cracked head bolts.
Fix costed me $5400.
Other than that it's running great.

 

[doug_engel]

The head bolt issue was fixed around 2010 or 2011. Even if you have a car with the old head bolts, they can be replaced fairly inexpensively as long as they haven't failed.

Another common issue which has not been fixed in later models are the cam adjusters. Again, if you start hearing them tick on a cold start, getting them fixed right away as opposed to waiting for a valve to drop into a cylinder will save you a ton of money.

There are a lot of examples out there with 150,000 + miles. If you take good care of these cars, they should run fine for years. Hope this helps.