intence

only $4200 initially for headbolt repairs? isnt that a good deal?

Dunkin_63

I apologize if answer is somewhere in these threads and I missed it.
But does anyone know if it's possible to pull the valve covers and pull one bolt to check for rust?
Without messing up the timing..

Still new to the M156.

Critter

You do not realize just how lucky you have been, by having a independent machine shop work on the heads which by the sounds of it the shop either used the wrong valve guides or reamed the guides to a too tight tolerance which caused the valves to stick. Mercedes rep must have been drinking heavily on the previous weekend to allow coverage of the engine after the head work was done.. Not giving you static , but boy are you lucky.

motoman

Dunkin, Some would replace the old bolts one at a time. So you could check if you like that method, but then replacing with the new bolts makes better sense since you are already there. We do not know if one or two positions in the head are especially vulnerable. But snapshots of 10 removed bolts, for instance, do not show numerous bolts broken, usually 1 or 2.

DuaneC63

Unfortunately this won't work for several reasons. The head bolts are torque to yield and cannot be re-used. The head bolts must be torqued a series of times in a specific sequence. Undoing one head bolt and then replacing it will a new one may have the unintended consequence of causing a head gasket failure. Some of the head bolt are underneath the cams and cannot be accessed without removing the cams. Hence it is an all or nothing process to replace them.

BRV518

Any particular engine model numbers that were affected by this? I got a 2009 recently was curious is all

Curious if Im in the affected range WDDGF77X09F320315

2year warranty so Im not to worried, but not too happy I found this information after I got the car. *knocks on wood*

Valvestud

Yes you are.


Joe

BRV518

Sweet! guess if it happens then it happens.. I dont want to worry myself over something I have no control and only have had the car for just over 2 weeks. I got it to enjoy it not stress lol I do wish anyone luck thats outside of the warranty since that seems to be when it usually occurs most.

I already let my dealer know Im aware of the issue so fingers crossed.

Thanks Joe

average joe

Do the cams really have to come out??? I am replacing mine with the weistec studs and was told I can do one at a time by a number of different people

I am only changing mine as a precaution.

Merc63

Yes all 4 cams are in the way of the bolts.

The cams are easy to remove with the MB tools and the engine at 40degress, the mb tools lock the cams in the correct position for removal and install.

jvanbrecht

And for such a simple tool, it is stupid expensive.

Interestingly, the Online price is 190ish, the msrp is 160ish.. part is 156 589 00 61 00

-Marlin-

Ok

-Marlin-

And another thing. .

Merc63

Errrr wrong. Tons of guys driving around without a problem. Guys even running blowers with these bolts, nitrous too!

Some pop, some stretch, some don't. Enjoy your day.

-Marlin-

I hear ya.

Jasonoff

I can tell you there are. I have spread the word about selling mine and I've had a few people ask me about it.

I'm almost thinking I have to swap my bolts out just to unload it...

Bud Wilkinson

I fully agree Marlin and spent some time screaming into the wind myself.
Rather than wait for MB to "Do the right thing" in this complete engineering failure, I decided to pay the bill and get it back on the road after the catastrophic failure of one of my head bolts. Car is awesome and I'll never see a dime of reimbursement as I bought it used post factory warranty without doing the full research based on the performance and reliability of my two previously owned bulletproof MB cars.
I will say that the cost of the repair shifted this car from a decent value purchase to one of the worst value vehicle purchases I have ever made. I could have bought an extended warranty at the time of purchase but didn't as I have done this in the past and wasted a few thousand dollars in the cost and interest as they were added to the contract. In this case it would have paid off in spades. My crystal ball was broken that day I guess.

Having said all that, the car is still the best car I have ever and likely ever will own.
I say buy the extended warranty and enjoy the car for what it is. AWESOME!

Unbreakable1

Since I am mechanically challenged, would it make sense to have Long Tube Headers installed at the same time as replacing the HeadBolts? or is that a completely different set of parts/install?

CarHopper

Completely different.

Although the name may be similar they are completely different parts in complete different parts of the engine.

These are headbolts (technically these are studs but this is where the head bolts go). You're just thinking of where the headers connect which isn't even shown in this picture.

Unbreakable1

thank you for the response!

Sincity

If the heads have to come off for the replacement (some have talked about replacing them one at a time without removing the head), then the exhaust manifolds have to come off and there will be an overlap of labor. What does that mean? It means that it would cost you a little less to swap the headers. If the headers and headbolt swap are in the near-future, I'd have it done at this point.

Unbreakable1

thats what i was wondering! i understand that they may not be in the same exact area, but if I were to have headers installed, it would make sense to do the headbolts at the same time

my C has 27k miles and i dont have any reason to believe my headbolts are in danger, other than what has been discussed here, how many are changing them as a preventative measure?

Starky_

My 2010 still has 2 years of extended warranty so I'm not too worried at the moment, but still checking oil/coolant levels regularly. Engine runs perfectly fine at 60k km's.

Will probably look for a good indie shop and eventually get them replaced before warranty ends though

Sincity

It's the other way around.

If you are doing head bolts, then swap the headers. If you are only doing headers, then the heads do not need to come off.

Unbreakable1

oh..lol