OK, I decided to google this. Here is an interesting entry from the world of BMW's:

I've had some experience with these. When I put the motor from an '87 325i into my 528e I had a lot of dealings with Peter McHenry (I hope thats the right name...) who is widely regarded as "the" expert on BMW small six engines. He told me that before I even start the engine I should replace the head bolts if they were the standard type. You can look into the oil filler cap and see the head bolts, if they look like they take an allen wrench you're OK, otherwise REPLACE THEM SOON!

The replacement bolts are Torx head type and designed to stretch. The older type had a nasty tendency to snap the heads off, causing major damage.

Peter said that I didn't need to replace the head gasket or remove the head at all. Just replace the head bolts one at a time, so the others remain torqued. This would be a good time to replace the head gasket if you think it might need it in the near future. (good time to adjust valves, too)

The local dealer said that they had not heard of this but were 'surprised' that they changed the bolt style (yeah, right). Then about six months ago I saw an iX in the shop getting some serious engine work done. I asked what happened to it and they said that a head bolt had snapped (surprise!) causing water to mix with the oil (bad) and the owner drove it home and then to the shop (REALLY bad).

If you have one of these cars it is in your best interest to change these bolts. It is inexpensive (<$40) and only takes about an hour to do. You will need a good Torque wrench and a Torx bit (I forget what size).

 

Good find! I know you can do the intake manifold bolts one at a time on this car so I just can't think of any specific reason why you can't do the head bolts before they fail either.

 

I'm no certified mechanic, but I going to say the seal between the head and block is more critical due to the high pressure in a combustion chamber. Get it wrong and you may hydrolock the engine like a broken headbolt. The worst an air leak in the intake manifold is just going to probably give you a slight improper air/fuel ratio since it is past the MAF sensors.

 

Great points.

 

Agree 100%. The environment is totally different - think of many thousands of explosions going off in your combustion chambers every minute - with only the head gasket in the way.

 

A more important gasket that seals in higher pressures yes.

However, there's still no technical proof how removing 1 bolt on a cold engine could compromise the gasket.

 

Car was running fine until one night whilst driving home I got a low coolant light. About 30 seconds later the CEL light came on. I stopped for about one minute (to check the manual) and then started again after reading the car may be in limp mode and I should go to an MB workshop soon. About 20 seconds after starting again lots of smoke, turned car off and called roadside assistance.
This all happened in less than 2 minutes of running time, all was great and then the issue. I did have to add some water between services but thought nothing of it and the car was running fine. I had it serviced 2 weeks before this happened.

I still love the AMG brand, the C36 has been a great car and we have owned it for more than 10 years. The SL500 is the same year but a totally different car, relaxed and a crusing car. The AMG's and the 911 are much more urgent. All good fun.

 

Man... i just received my 2012 C63 AMG. should i be concerned with this related issue?

 

No. Only up to some 2010. 2011 and later have been upgraded from the factory.

 

Phew.... thanks for putting my concern at ease. for a minute there i was gonna go mental at the service manager for not disclosing any recall notes to me during the PDI.

 

There is no recall for this issue, just a TSB. Enjoy the car!

 

That's part of the problem. But also, a full recall would be quite painful to MB/AMG, I suspect.

 

Well it looks like I could be next up to the plate on this issue.

I get a low coolant CEL each time I cold-start the car. Nothing when the car is running through.

I have a 2010 P31. No idea what my engine # is. Will schedule a service appointment first thing Monday.

Anything I should say / ask when doing so?

I will report the whole process back here as another data point on how MB handles this issue.

 

I used to get a low coolant CEL often with my 08 GL450. I simply topped it off every time. I wonder if this is somehow related.

 

Thank you for your willingness to keep the community updated. I hope your car is okay.

 

Make sure you check your tailpipes on cold startup to see any excessive white smoke and also check for any coolant leak around the block. How much water do you need to top up?

Thanks for adding to the thread and good luck!

 

You have the classic headbolt failure/head gasket symtoms (assuming your coolant resevior is not cracked). Take it in a immediately. They need to keep it overnight to check the problem.

 

Ok so I took the car in first thing this morning.

I went through my salesman, who put me in touch with the right guy at service. They were great, and told me to bring it in this morning. I did, they brought the car in and checked it over while I waited. There were 5 other people in the waiting area and they had me in and out while all of them waited there.

They told me the car is fine, they topped up the coolant and sent me on my way.

I should clarify that I only had a 'low coolant' indicator message, but no actual check engine light.

What they did tell me was that there are no service bulletins for my car. Maybe he meant recall? I'm not sure.

My engine build number is within the head bold issue range, about 1000 before the last one identified (059xx60060658) Production date for my car is May 12, 2010. I currently have 22,590 kms on the vehicle.

I asked about the email posted earlier in this thread and they said they didn't know anything about it, and that service bulletins vary from country to country (I am in Canada). This dealership knows me well (I have bought 3 cars from them and deal with the GMs son) and I have no reason to believe they'd intentionally give me the run around.

So it's hurry up and wait for a more symptomatic problem to present itself. My advice to anyone worried about this is make sure you have the actual CEL + the low coolant message on the instrument cluster before freaking out.

 

I wonder what is MB of Canada's position on this? Remember when Jeffield (Vancouver BC) had issues with his motor?. His motor (2008) had to be replaced and they couldn't give him a reason why the motor needed replacement other than blaming it on his straight downpipes (no cats). Jeffield's motor was repl sometime last year (with contribution on his part) before all of this headbolt issue reared it's ugly head. I met up with Jeffield a couple of weeks ago and to this day he is still scratching his head and feeling his pocket several thousands of dollars thinner.

 

I think MB Canada would be the same as any other country. No real reason to think otherwise?

Even though my 'issue' turned out to be nothing (for now) I have decided I will not own this car out of warranty.

1. I learned I am within the engine build range discussed earlier in this thread
2. There is nothing my dealer could tell me about this problem, which makes me suspicious that it may not be acknowleged upon failure
3. The cost to repair if it fails is just way too huge to take the risk.

I'll continue to drive it enthusiastically, and will follow the maintenance schedule as it shows up on my instrument cluster. If I decide to keep it as it nears the expiration of the warranty I'll buy an extended one.

 

Hopefully they gave you documentation that you had a problem...otherwise no proof

 

For what its worth ... I track the living hell out of my 08 ML63, it has 60k miles on the motor, and I have had zero issues whatsoever.

However, I have no proof if the motor was rebuilt before my ownership. I have owned it since 45k miles and had no issues since then.

I do have extended warranty until 2014 tho so I guess I can rest easy knowing I am fully covered.

 

This is what I've been thinking about lately. Imagine the following scenario:

1-2 years from now, a married man, with a couple kids decides to buy a used 2009-2010 C63 that is nearing the expiration of the MB express warranty. He earns less than $100K/yr. He finds one for sale in $30K range. The car is not that expensive and the husband can afford the payments and can maybe even pay cash for the car.

1-2 years later the engine hydrolocks caused by the defective head bolts. The repair bill exceeds $20K. His car is a big paper weight until he can rebuild the engine. The repair bill will destroy his family's finances.

Sure, the man took a gamble buying an AMG with an M156 that is nearing the end of its warranty. But, if that's the rational against purchasing this car, then anyone who is not able to afford the repair bill of an M156 should not purchase one. And that criteria would severely limit the used car market for these cars. Most buyers that can afford it, will choose to buy a newer vehicle--one with most or all of the MB express warranty remaining.

These engines are supposed to be amazing. They are supposed to represent German craftsmanship. And for the most part, they are everything they are promised to be.

If an engine fails from time to time because of any number of reasons not caused by a design defect, well, then, that's just part of life. **** happens. But, here, MB made a mistake. They know it and so does everyone else. I don't believe MB should pay for every M156 with the defective head bolts to be repaired with the new headbolts. That would be too expensive and many M156's with the defective head bolts will never fail. So, it would be a waste to repair them all.

But, MB should do the right thing and extend the express warranties for any issue that arises due to their company's design defect. Equity demands this. Anything less is playing with people's financial well-being.

 

1st of all I don't want to sound rude but this is how I feel.
#1 people give these cars way too much credit from thinking that are the fastest and best thing since sliced bread.

#2 when you buy car with a simi high performance as the c63 you should expect to pay high repair bills and if you can't afford it then I'm sorry this is not the right car.
I
#3 why in hell ate people making such a big issue out of this head bolt issue.
In no ways should it cost 20k are you kidding me right now? Go to independent shop and you should get out with under 4k. It's always the same people who think the dealer is the best place to go for repairs.news flash I would and have never taken my car to a dealer even if it's under warranty. They tend to break more crap and cause more harm then good.

One last thing YOU PLAY YOU PAY

 

RE: your point # 1: People take these cars seriously, because they are serious, high performing super sedans. That's a fact.

RE: your point # 2: You miss the point entirely. In fact, I already mentioned that sometimes **** happens, as in, sometimes there is a bad batch of parts and someone is unlucky to receive a car with those parts. That's life, as I mentioned. But, here, as I mentioned, this is a design defect. Why else would MB/AMG change the head bolts? Because they could save money? No. Because, the first batch of head bolts are not dependable. Customers should not have to pay for a repair that was caused by MB/AMG's negligence.

RE: your point # 3: You're wrong. Rebuilt M156's cost more than $5K even at an indy shop. I know you know what catastrophic engine failure is, and if an engine hydrolocks, that's what can happen.

"Pay to play" has no application here.