AWD_AMG

I posted this in the sticky thread at the top, but wanted to make a dedicated post for those who might miss it.

The understanding has been that all 08-09 C63s have the old headbolts, and that a significant number of 2010s do as well, but that the 2011 models are safe. The engine number cutoff is 60658.

I previously mentioned that I had not found a 2010 with the new headbolts, and I just found something a bit uglier:

I ran the VIN of a 2011 C63, reflecting a delivery date of 07/06/2010 in EPC. This car has been identified as a 2011 model in both autocheck and carfax. Anyone want to guess which side of 60658 the engine sits on? I'll give you a hint, it's below 60500...roughly 200 below 60658.

In conclusion, ALL 08-10 C63s have the old headbolts, INCLUDING very early 2011 models.

callmiro

Have you headbolts failed?

AWD_AMG

No. All I'm saying is that there are 2011 models in the "affected" group, and that the original understanding that the change was made in the middle of MY2010 models is incorrect.

callmiro

i just find with all these threads that its just a little dramatic to call them bad headbolts....the majority of the cars produced have never encurred a failure.

AWD_AMG

All I did was provide additional information to help the community have a better scope of a potential issue by providing additional information to prevent the spread of misinformation. I never said everyone's engines were about to explode.

If something has a potential to fail vs. an updated design that does not, then yes, I would make it a bad vs. good argument; my statement was not out of line.

callmiro

Yup...thanks for the research

Merc63

I love my ARP studs!

rory breaker

thx!

mthis

Can u tell me why my dealer ran my vin and told me I'm "safe" and i have a 2008?
29969.

cloverfield

I think the title of this thread is misleading. Since the car has not been diagnosed with "bad" head bolts, I think it should be changed to say "old" instead.

Regarding the engine number 'cut-off' for the updated design, is there an internal document or revision code to reference? Or is this a running change in production and the cut-off is our best guess at said change?

AWD_AMG

I understand what you're saying, but Mercedes used a different type of headbolt for a specific reason. How many headbolt issues popped up by this time three years ago? They're aware of the issue and have changed their design to prevent a damaging design flaw. I don't believe calling them "bad" headbolts is incorrect vernacular. Calling them "old" is also valid, but if they weren't "bad" then they wouldn't have changed the design.

The engine cutoff number is noted in 01-05-2012 Star Bulletins LI LI01.30-P-051567_Ver.1a. and can also be read about here: http://www.marcusfitzhugh.com/CLK/63.html

And again, to be explicitly clear, just because your car has "old" or "bad" headbolts does not mean that they will fail, but it has been proven that they have the potential to; there are PLENTY of healthy 08-10 C63s running around (If not almost all of them).

bhamg

Good info AWD, thanks for posting.

motoman

Sometimes I think worried owners need a bogeyman like we need Iran. Something to worry about, but not really solve. Like the times I have offered to have forensics done on failed headbolts vs improved ones. No one will respond or furnish them to me. Worry on.........

Fung63

i have a 2010... obviously in the bad headbolt range. I slapped on ELW and called it a day. Doesn't affect how I daily drive my car nor does it make me overly worried. remember it is just a very slight chance something can go wrong. The majority of the cars in this range will have no issues throughout its life.

Love the car... enjoying it everyday

bhamg

Damn motoman, I was wondering what happened. I thought you had them for a while now.

_timothy

would MB actually let someone take the failed bolts?

bhamg

Most likely not, but Merc63 had pulled some very corroded headbolts out of his engine that motoman was trying to get ahold of to test.

motoman

bhamg, The offer stands. You will never get the bolts from MB on pain of lash and termination. Only an indy or owner can get the headbolts. So far the valued members of this forum have not provided any and only one has PM'd me. We have all watched too many zombie flicks and need this nightmare, I guess.