carjones

background: got my c63 back from service about three weeks ago. I was driving home three days ago, "check coolant level" comes on.
I think 'probably normal consumption."
get home, allow to cool, add about half a liter, looks good.
Next day, driving to work, no drama, then same message.
I think, I must have not quite added enough.
Allow to cool, now it takes 2 liters.
I think, can't be leaking, as none in the garage and none in exhaust smell.
Next day- same thing
At dealer- at first they said they would test the system.
Today they called, need to keep the car for a few days.
May need to pull heads.

2009 44k miles.

I pretty much baby this thing, only issues was having the intake leak repaired that many of you have had about 6k miles ago.

I'll let everyone know how it plays out. Dealer has always treated me well and been very upfront.

bhamg

Sorry to hear that...looking more and more like a MY 2009 issue.

Merc63

This really worries me as its been only occurring on cars with high mileage and seems to hit once warranty is up.

DuaneC63

The ECU is programmed to have the head gaskets fail right after your warranty expires.

Faris63

That's true

carjones

I was careful to document all service after reading other members encounters. I just had the "B" service completed and made sure I was following the required maintenance.

Sincity

It IS the bad news. This is un-nerving (sp?). Another person with a coolant issue. Based on the number of active members here on this forum and the # of potential failures, the failure rate is unacceptable.

Does anyone have an email address of a contact person? My '09 has 5640 mi and warranty will be up in June '13. At the rate I'm going, my failures may come after warranty which may lead me on not keeping the car though my original plan was to keep for a long time. I could always spring for an extended warranty, but will need to read the policy language on a lightly modded car. Anyone have an idea on costs to replace headgasket and bolts as a preventative measure?

EDIT-correct current mileage to 5600.

bhamg

Sin - Did you add an extra "0" to your mileage?

carjones

Update-

Heads are coming off, new gaskets, and lifters.

b16

Took my car in for a service yesterday and the SA mentioned there is a service bulliten for this. She said if I get the coolant light to turn the car off immediately and have it towed to the dealer.

ZephyrAMG

+1 LOL I thought when we last checked with him he had like 4000 miles on a car 2 years old...

DuaneC63

I not sure what the consumer laws are in NV. In Cali if you bought the car new from the dealer you can buy the factory extended warranty at any time prior to the expiration of the primary warranty.

DuaneC63

These must be failing for a reason. Head gaskets aren't exactly a high tech part. Perhap having the head bolts retorqued every 25K might help avoid the problem. It's hard to believe that an AMG motor would be designed with insufficient size, strength or number of head bolts. If they do pull the heads make sure they are not warped and the deck of the block is perfectly flat.

PaulWdz

That might be the problem.

Merc63

M156 use Torque To Yield head bolts. They are stretched to a specific limit, but if they are over stretched slightly they lose a lot of their strength which can cause these failures we are seeing now.

I am not sure if its the heat, the metal or if they are being torqued too much which is causing the over stretching and weakening. But clearly something is not right.

Here is a good article explaining critical fasteners.

So re-torquing the bolts is definitely not an option. I believe you should only use a Torque to Yield bolt once. I know there is some on the bottom of the tranny pan and I had to use new ones when we did that job.

http://www.enginebuildermag.com/Arti...uetoangle.aspx

black-clk500

WTF, good to know.
Anyone know if this is 09 specific or early models specific?
Can't recall seeing any 10's or '11s with this problem, YET.

Jons95c36amg

09 here and has over 25k with no coolant usage.

bhamg

We need a catch-all thread across all forums where the 6.3 is used. We've had maybe five threads in two months here with the OP's experiencing head bolt failures and they all will drift down into oblivion eventually and probably be difficult to find with the crappy search function. Let's track this issue (better)!

Weistec

Hello Gentlemen we have briefly wrote about this in a similar post regarding these issues. We have an ARP Head Stud available for the M156 and M159 that is far superior to the factory torque to yield bolts, is reusable (if ever you need to remove the head again), and is very easy to install. We highly recommend these for anyone that is removing the heads, either for repair or modifications. PM or email us for more information. Thanks guys.

Weistec Engineering

Even Money

Good to know, could you pm, start a thread or post here what parts you have for the M156 that replace OEM parts. Thanks.

BerBer63

price, expected time for install?

Sincity

You're right. Current 5600 mi.

Sincity

+1. Sticky it!

bhamg

At this rate based on my calculations you have 23 years before probable head bolt failure.

carjones

Another update-

They are reporting one head bolt had failed and another had area showing corrosion.
I certainly would reccomend watching this on the '09 MY vehicles. In my case there was no early signs, just an immediate change to what had been a normal ownership experience.
I would never recommend reusing head bolts on any rebuild, but especially if you are going into one of these motors for modifications, I would definately replace all of the headbolts with a superior fastener. Most who do this type of work already know this.
If there is someone that has information regarding the TSB on this, we might know the range of affected vehicles.