x14828

Didn't realise my first post would be about a broken headbolt, but thanks to this board and the wealth of knowledge before buying my car, I couldn't have been more calm and educated about this issue. My mechanic said he has never seen anyone more relaxed about a $3500 repair bill. He said most people show up with sharp metal objects when he explains how a $12 bolt can cause such catasrophic damage to their bank account.

Mine is an '09 C63 with about 80k(that's in KM, about 50k in miles). Previous owner was a friend of mine from new and my knowledge of the car history was probably the only reason why I took a leap on a used high milage, high performance German car without a warranty. We agreed that the headbolts would eventually become an issue and gave me an appropriate deal on the car.

The cost to do a headbolt job with new gaskets and cleaning was about $2.5K(in USD), my lifters were on its way as well so that added another $1K.

What was interesting was that the shop used to be a independent Merc shop but because so many cars came in for headbolts that they are now a shop that simply specializes on M156 headbolts. The number of headbolt repairs they do on a weekly basis is quite scary. He said in every engine he opened with the effected headbolts were either broken or on its way to being broken. He has seen cars go well past 100k before being broken and some that wouldn't last 20k... but he is quite adamant that it's not an issue of if, but when.

The good thing is that they have this repair perfected so the cost has come down significantly compared to the past when he charged well over $4K during the first batch of effected cars.

I bought my C63 because I knew this would be the last of its kind. It would be something I will tell my children how the world was once a great place where shoehorning a naturally aspirated 6200cc V8 into a compact family sedan with no regards to self-restraint was a good idea.

I really owe this board a load of thanks, especially to the early 'pioneers' who must've gone through hell trying to resolve this issue.

SuperFastYo

Oh great, you just reassured my deepest darkest fears. Thanks!

vtune

whats the name of this shop?

JPetros2008

and where is it located?

chrisridebike8

Now I wish I had done headbolts earlier.

s.e.a.n.

Same thing happen with my 09 shortly after the purchase, had to change the head bolts, lifters along with the cam adjusters.

Dogtag114

Is there an easy way to see if a previous owner already repaired?

Jasonoff

Only way is to yank the valve cover and visually inspect.

Mag1c Carp3t

It would be in the car fax Maintanance history. If the owner did do it, it would definitely be noted and bragged about as it can help sell the car.

Mag1c Carp3t

I would take advantage of this situation and have the heads sent off to a machine shop for a pnp. This is the one thing that makes me believe it's ok if it happens. I got a quote for $1500 for the pair of heads. Shop said a claimed 20hp increase. I was also quoted $2500 for my head bolts.

aussie e55

hi X14828
where in the would are you thanks

Celicasaur

lol that's exactly what I would do too! it would add a silver lining to an otherwise dark time.

m a x i m u s

I agree. You already have the thing taken apart anyway.

604 C63

well, thats a helluva first post. Lets hope we get a second, with a name/location of that shop.

And I love this.....

Yeah, thats the sweet sweet candy that got us all hooked lol.

Mag1c Carp3t

Figured I'd post up my quote for the preventative repair.

SuperFastYo

3k is not bad at all

I just don't understand why this wasn't a recall...

chrisridebike8

With the heads off, is it a good idea to do the timing chain guides as well? And if you add on cam adjusters, how much does that add? Thanks!

Jasonoff

Cam follower, FFS, another name to call them

SuperFastYo

Get it pnp while your at it too!

s.e.a.n.

Cam adjusters are $650 each. The M156 uses 4 so that $2,600 just in parts not exactly cheap, neither is PnP since everyone is throwing that around.

Vladds

Why no exhaust manifold gaskets?
I don't think they pull the heads with the manifolds attached and separate by the front converters, hm.
Why no TTY aluminum bolts for the intake manifold?

Mag1c Carp3t

I was quoted $1500 for my pnp job with gains of 20hp. I don't find this expensive.

SuperFastYo

well good sir, we are in two entirely different tax brackets.

Celicasaur

That is actually quite a damn good price - especially as it includes AMG tax.

Mag1c Carp3t

Wasn't speaking financially. I guess the proper way about this was asking how you believe this to be expensive.