C63 Head Bolts - How Problematic?

[eztiger]

Gearing up for a potential purchase (c63 on the list of candidates) - how much of a potential issue are the head bolts really?

I'm currently ruling out all pre 2011 / facelift c63's from my search. Which is obviously bumping up my budget requirements quite a bit and restricting the cars available.

Is default ignoring all potentially affected cars for purchase a rational decision given the potential risk?

How much would it cost at a decent independent (ballpark) to have the bolts replaced with the updated MB parts or aftermarket equivalents (Weistec?) to allow this to be built into the budget for an older car purchase.

[lee c63]

Ironic you have posted this as mine is currently having the bolts replaced with Weistec studs as a precautionary matter.

If your buying the car with a MB warranty and are not planning on doing any engine modifications then the head bolts are covered by warranty and would be replaced at no cost should they fail.

[eztiger]

lee c63 said:

Ironic you have posted this as mine is currently having the bolts replaced with Weistec studs as a precautionary matter.

If your buying the car with a MB warranty and are not planning on doing any engine modifications then the head bolts are covered by warranty and would be replaced at no cost should they fail.

Fair point though an MB warranty on a used car would only last a year?

I don't know what the costs are to extend it - especially compared to the costs in bolt replacement.

I presume an indicative cost of replacement would be hard for you to give as it's probably rolled up in other upgrade work? (I have stalked your other threads with jealous interest..you have a lovely, lovely car )

[lee c63]

It's roughly £600 for the studs
£500 for the valve buckets
And I would dare say labour is from 600-1000 pounds......and you want so one that knows what they are doing with the correct tools.

I will keep updating the thread I started with pictures,progress and any anomalies etc as it goes.

[eztiger]

lee c63 said:

It's roughly £600 for the studs
£500 for the valve buckets
And I would dare say labour is from 600-1000 pounds......and you want so one that knows what they are doing with the correct tools.

I will keep updating the thread I started with pictures,progress and any anomalies etc as it goes.

Thanks useful info. Back of an envelope £2k cost.

[W8aMinute]

Aren't there details of the affected engines' production codes floating about the interwebs?

[daveenty]

W8aMinute said:

Aren't there details of the affected engines' production codes floating about the interwebs?

Developer gave this useful info about the engine codes on another thread: -

developer said:

The head bolts were modified at M156 engine number ending in 60658. The bolts went from female torx fitting to male torx fitting.

The correct procedure is to remove the heads and replace the head gaskets. Replacing the bolts one at a time isn't recommended, due to the potential for the head gasket to fail.

If you were to opt for Weistec studs, as Lee has done, I understand they can be fitted one out, one in, but I doubt an MB dealer will be interested in that.

[Nickellese]

lee c63 said:

It's roughly £600 for the studs
£500 for the valve buckets
And I would dare say labour is from 600-1000 pounds......and you want so one that knows what they are doing with the correct tools.

I will keep updating the thread I started with pictures,progress and any anomalies etc as it goes.

In my experience the labour is considerably more. I've just had this issue rectified on mine and the total cost at MB Bath was way more than this, even with massively discounted labour rates. Perhaps the difference was because mine had failed so needed parts to be checked for conformity vs. preventative maintenance.

[lee c63]

Nickellese said:

In my experience the labour is considerably more. I've just had this issue rectified on mine and the total cost at MB Bath was way more than this, even with massively discounted labour rates. Perhaps the difference was because mine had failed so needed parts to be checked for conformity vs. preventative maintenance.

My figures were for an independent and just changing one bolt at a time so no requirement to remove heads.
I would imagine MB rates would be in the 5k range ( which is ok if it's warranty work). They don't have that fancy showroom and free coffee charging you normal rates lol.

[lee c63]

Nickellese said:

In my experience the labour is considerably more. I've just had this issue rectified on mine and the total cost at MB Bath was way more than this, even with massively discounted labour rates. Perhaps the difference was because mine had failed so needed parts to be checked for conformity vs. preventative maintenance.

[eztiger]

Any comments on how common this issue *actually* is given the number of engines out there?

I mean it really causing an issue as opposed to being in the affected range.

All of the above really says 'stick with the facelift for an easy life'.

[lee c63]

It would be hard to say how common it is....remember it's the engine not the car so it's fitted to E,S,CLS and ML
I spoke with AMG newcastle and they had only seen 1 case ( on a ML63).
However MB did change the design so it's more than a handful.

My main reason for changing was due to installing the Supercharger which increases pressure in the head so in theory increases the stress on the bolts. Paying a couple of grand for the studs just gives me the peace of mind.