mdbenz4me

I am in the market for a C63 but the whole head bolt failure issues points me in the direction that I should shoot for an 2011 or up.

Is it inevitable that the older designed bolts will fail? Or is this happening to modded cars only? I plan on keeping the car stock... tune at most... but not if these bolts will fail.

Karl901

If the head bolts fail, why not replace them before they do?

ddcha

no one seems to have a definitive answer to this question. the issues with the older bolts led to MB to change parts mid production. yet, there are plenty of 08-10 owners that haven't had an issue and there is no full recall yet.

Karl901

What happens when the bolts fail?s

black-clk500

Engine hydrolocks and you got a BIG bill to pay

Buy a car with a warranty and forget about it, there's plenty of other expensive things that can break on these cars, so driving one without a warranty is just plain lunacy IMO

ddcha

yeah, that seems to be the overall advice I've seen. Keep extending the warranty as long as you own it. Then let whatever happens happen...

mdbenz4me

Anybody see why Fidelity Platinum warranty would not cover this as long as the car was stock?

cyberorth

My vote is this:
If you look at it from the mb's standpoint, it needs to make financial sense to do a recall. If too many engines fail, it costs mb more to repair after the failure than before, so mb may consider a recall. Otherwise they would repair each incidence under a tsb. Conclusion: at this point probably very few 156s are failing.

Karl901

Is there a way to tell , via VIN # / engine serial #, if I have the defective bolts?

Karl901

Is there a way to tell , via VIN # / engine serial #, if I have the defective bolts?

GrnLantern

From the VIN, someone with STAR TekInfo access can get the engine number. From the main thread on this issue (https://mbworld.org/forums/c63-amg-w...oncerns-2.html), there is this:

DuaneC63

If the engine hydro locks you might be looking at new motor worst cast ($40K). If you catch in time (low coolent level, white sweet smelling smoke, etc) it's still a $5k fix. Even if yours doesn't go out, thing about all the grief your going to get from potential buyers when you try to sell it.

BlownRT10

The title says 09-10, but do the 08's have the same issue?

b16

Yes, any 63 engine prior to sometime in Mid MY '10 has this.

Merc63

Its rare. My local dealer hasn't had one fail at all.


I wouldn't be overall concerned about it.

The price of replacing with ARP head studs is not cheap, thousands. The parts alone are 900$ Labor probably $2500-$3500

I have a spare engine if you hydrolock yours

In reality, guys are seeing coolant loss, aka coolant is seeping into the cylinders and being burned off. It would take about 100cc+ of liquid quickly entering the cylinder to hydrolock the engine.

If you are seeing the low coolant sign, you have a serious problem and need the headbolts replaced immediately.

Chocofishez

I just had mine into the shop today on suspicion of having this issue. They couldn't tell me anything about it. They topped off my coolant and sent me out.

My car has a build date of May 12, 2010. There are about 1000 engines between mine and the last one before the new headbolts were installed on all '63s.

I won't own the car out of warranty because it is within the range. If I were buying one used I would only consider a CPO car with an extended warranty covering the whole drivetrain.

Merc63

That's complete bullsh{t

An engine does NOT lose coolant unless there is a leak. If there is no leak, the engine is burning it and there is a head gasket sealing issue.

I would fight this with them as they are just shoving you off and hoping it doesn't fail while the car is under warranty.

There is a bulletin in Canada for cars burning coolant now I believe, check around for it and educate yourself.

1Lop2K5C

I would think it depends on the mileage the car has. I wouldn't think a car could keep all its coolant intact. I spoke to my MB tech and he has indicated that you would see a bunch of tell-tale warning signs when the bolt failed prior to hydro lock (maybe he is saying this to make me feel better).

otakki

It's unfortunately the owners would have to wish for the failure to happen soon so at least it will be covered under warranty. Well, I guess it gives me a reason to trade it in for another vehicle before my full 7 years warranty runs out.

Gosh, I'm gonna miss the last N/A AMG engine (not counting the SLK55).

bhamg

Please have him inform us as to what those warning signs are other than coolant loss. I'd like to know.

shades

Exactly....mine had the head bolt issue and there were no signs at all. No leaks and no loss of coolant. It happened to me on the highway just when I started to push her hard and all of the sudden puff of white smoke...looked down and my car was in limp mode. Got it towed to the dealer, $20k later I have a rebuilt engine courtesy of MB Canada.

drawde

are you saying they said they would cover it or wouldn't? hopefully they do as i have fidelity as well.

mdbenz4me

After more research, the headbolt is technically be considered a fastner, which is not covered by Fidelity Platinum or MB for that matter. If you have a good relationship with your service advisor and kept the car up, MB may be willing to help you out.

morganb

Mine was similar though not even pushing hard at the time of failure. I topped up Coolant after about 6K KMs between earlier services one time. 2K KMs after the last service low coolant light comes on and about 1 minute later the CEL. MB Aust told me about A$ 35 for the rebuild.

otakki

Not covered by MB, either? Then what's the point of getting the factory extended warranty? Might as well use the cost of the extended warranty to pay for the elective head bolt change.