adv4nced53

LOL what? I try to stay away from forum argument nowdays but this one was too funny. So let's ignore that since it's wrong and has nothing to do with the topic here.

There's a correct way and an incorrect way to do things. Doing the swap one bolt at a time is incorrect. Could it work...yes. Would I do it...no. There are reasons torquing patterns exist. The head flexes as you torque it down and the pattern also drives air out. When you undo a bolt, you risk affecting both of those. Also, headgaskets are designed to compress and reusing one that is already compressed by swapping bolts one at a time is not a good idea. Knowing that, go ahead and make your decision. In my eyes, you can total the car tomorrow so why fix something that's not an issue.

Also, who said you'll hydrolock your engine if you blow the gasket...LOL

Ingenieur

what's 'wrong'?
since you went to the trouble of posting and commenting please share
start with M = V (Pme) / 4 Pi
V = displacement
Pme = mean effective cyl P
Pi = 3.14156,,,
4 = integer between 3 and 5

if you note I did say I would pay some one to do it properly
but if you are going to 1 bolt it at least release the stress on the head

driving the air out? now that is a hoot
with a compressible gasket and 140,000 lb (600 psi) of force, compared to atm pressure of 14.7, I'm fairly certain the air would be expelled

you generally start in the middle and work outwards to make sure it lays flat and you don't constrain a 'warp'
sort of like ironing, push the 'wrinkles' out the unconstrained end(s)
loosening is generally the opposite

hydrolock: apparently some people have bent rods due to inducting coolant and attempting to compress it after the bolt had let loose
small chance but plausible

Ingenieur

APR stud replacement on a diesel
1 at a time with a bit more than stock torque when done
http://www.google.com/url?sa=t&rct=j...V-GYi6-n4MrU0Q

apparently it is a BMW approved shop method
BMW specifies that you can replace the head bolts without replacing the head gasket. This means that depending on how mechanically adept you are, the whole fix will take anywhere from 30 minutes to an hour. I really didn’t want to have to pull the head off just to fix a broken bolt! The important thing to remember before you begin is to replace each bolt individually. What this means is that as soon as you remove an old bolt, replace it with the new bolt before you continue.
Next, I used a small screwdriver wrapped with a rag soaked in brake cleaner and inserted it down the hole. This is important. You want to try to get the holes as clean as possible. If there is any dirt or grime in the holes, it can possibly give you false torque readings when you go to tighten the bolts. You’ll notice that the new bolts are coated with oil. This is to prevent corrosion from building up on them prior to installation. It’s a good idea to keep this oil on the bolts. It will help lubricate the threads when you torque the bolts down. Now grab the new bolt and thread it into the hole. Now using an internal Torx head socket, torque the bolt to 22 ft./lbs.

Now remove the bolt on the opposite side of the bolt just replaced. This will help to distribute the torque between the new bolts and old bolts. Repeat the process above, first cleaning out the bolt hole, then threading in the new bolt and torquing it to 22 ft./lbs. Just remove and install one bolt at a time and make sure they are torqued to 22 ft. lbs. Make a not of the order of which you install the bolts.

BMW has a specific process for torquing the cylinder bolts. It calls for three different stages. The first is the initial torque of 22 ft./lbs. The second stage is to torque each bolt a further 90 degrees from the first setting. Once all the bolts have been torqued the further 90 degrees, the last step is to go back and re-torque them an additional 90 degrees. The reason for the incremental torque is to allow the bolts to naturally stretch and expand without snapping them.

So, make a note of the order and begin torquing all the bolts. All you have to do is put the torque wrench on the head bolt and turn the handle 90 degrees. For those of you not too familiar with geometry, that’s ¼ of a turn. Be sure to mark where you start. I would go like this; Start at no. 1 cylinder intake side, then exhaust side, back to the next intake side, then exhaust side, do it in this order until you run out of bolts to torque.

Now, go back to the first bolt you turned 90 degrees, and turn it an additional 90 degrees. Now follow the same order again, and turn all the bolts an additional 90 degrees. Once done, you have successfully installed and torqued the head bolts without removing the head.

Ingenieur

oem cyl head torque spec and sequence
page 63
1st pass bolts 1-10 7.5 lb ft
2nd bolts 1-10 37 lb ft
3rd 90 deg bolts 1-10
4th 90 deg bolts 1-10
5th 90 deg bolts 1-10
6th 15 lb ft bolts 11-14

sequence is diagram 241 page 132

http://www.google.com/url?sa=t&rct=j...PHCuhDe0OjgogA

Merc63

So now are you agreeing with that method or do you just like to act like you know what you're doing?

I've been through this topic 100x now with guys that don't even change their own brakes but somehow have in depth mechanical knowledge lol.

Diesel guys and BMW amount others have been doing this for years. BMW had the same issues with head bolts popping off.

You think the gasket will move when you remove one bolt, you're nuts.

Ingenieur

not sure if I agree but it appears it is an allowable practice by some sources, but for everyone that says it is OK you will find sources that say it is not...take your chances

I did look in the Cat shop manual for several types and they recommend complete removal, NOT 1 at a time...

I looked in the BMW factory TIS and I could not find the reference for replacing 1 bolt at a time, they say do the whole thing, but mine only goes back to 1999 and the e30's were in the 80's

if I don't know something I research it and unlike you don't spout off nonsense without any rational thought...I may 'act' like I know something but you actually know nothing...

it's not that the gasket will move but the head may distort

that's why I would loosen them a bit all in the reverse/proper sequence
then install 1 at a time in the proper sequence
and as the APR article said, torque over spec a little bit

my concern would be breaking a bolt while removing

DuaneC63

I'm just quoting the MBZ non public service advisory procedure. I'm sure you can do one head bolt at a time but I'm not sure you'll get the desired result. Since you've already pulled everything off the top of the motor and locked the cams chains, the additional effort to finish pulling the heads and replacing the gaskets (as the only extra step is unbolting the exhaust manifolds) is worth the minor extra effort for greater peace of mind.

motoman

bhamg, This should be moved under the sticky?

With regard to cleaning headbolt holes. I will post source fo metric "thread chasers" (not taps) for any purist who wants to clean the block threads properly.

brano_co

This is exactly mine point of view, I was quoted 1,400 eur = @ 1,900 USD for complete bolts replacement at local MB dealer/service include the material & work

I had to fill in last 6 months & 23,000 km about 0,5L of fluid, so I am little bit worrying about this too.

I am going to do this at start of next year, just to be sure , they will don’t break during "some fun" in somewhere and I don’t have to spent 10,000 eur for new engine...

I just want to know, what’s can go wrong, once the official MB service will open till now the trouble free engine ?

artificer

From out of the woodwork....
Sounds like lots of advice from folk who have never spun a wrench for a living.
'Chasers' is about the first good sounding addition to this tread.
The rest is ongoing confusing waffle....
One @ a time I would do for a customer any day....& not expect a come back or re-do.
Drain coolant below head bolt level & go for it.
Frankly is a bit of a giggle or more aptly just a pot stirrer.

Ingenieur

laugh your *** off sonny

I know how fasteners work, at least more than you or the guy I was responding to

clamping force is measured in pounds(force) NOT lb/sq in or psi.
it is generated by the tension induced in the stretched bolt and does not depend on the combustion pressure of a running engine.

Any mechanic who does not follow the mfgs written procedure is increasing the likelyhood of a failure and losing arbitration if it comes to that.

hmmmm, the mfg and all his engineers, research, resources...or Joe at the corner garage...

should the new bolts be replaced 1 at a time in the installation sequence or the removal sequence?
should they be torqued to step 1 and 2, then when all are replaced the 3 angle steps in the install sequence?
replace them finger tight? then do the proper sequence?
or torque each one to spec as replaced? in what sequence? +10% torque? and extra 45 deg? any extra torque?

artificer

Red herrings are just that.

Clamping force is not a term normally used in Automotive applications or discussions, so its use here is unwarranted & as I said frankly confusing [waffle].

Torque is the term always associated with automotive fastening devices & that is measured in Nm [or ft.lb in that one place in the world]

I'll leave it to others to 'pound' away.

bhamg

Will do...

Ingenieur

technically
ft lb = work (F x d)
lb ft = torque/moment (F x r)



fasteners are torqued to a certain value to achieve a clamping force (basically torque is converted to a force to resist the movement or 'acceleration' of a mass , as in F = ma)
http://www.engineersedge.com/calcula...orque_calc.htm
pick a bolt size, and a torque to get the clamping force
in the case of the head you want enough to constrain combustion and contain the gas..
or the acceleration of the head away from the block

skaarlaj

If you become concerned about coolant entering a cylinder or two while the headbolt is out, just simply remove all of the spark plugs and spin the motor over with the starter a few revolutions to expel any liquid that may have leaked "in" while the bolt was out, and if the fluid only leaked into the cylinder while the bolt was out, and then resealed after being replaced / re-tightened, you'll be good to go. Of coarse don't try expelling the fluid in this method until all head-bolts are re-tightened.

If I thought that I may encounter a failed head-bolt, I'd certainly try this method of replacing the problematic head-bolt. But I think my year, has the issue resolved??

Merc63

You won't have any coolant worries because you drain the coolant and suck around the bolts with a minivac before removing the bolt..

Also it would be impossible for coolant to by pass the gasket with only one bolt removed. You still have 9 other bolts with tons of clamping force.

Ingenieur

if done 1 at a time:
should all bolts be loosened first?
if so, what sequence?
if not loosened first, what sequence should they be replaced?
should they be tightened as you go, or after all are installed? or partially as you go, then final tightening once they are all installed?
torque over spec? if so, how much?

if I were to do it:
loosen all bolts 3/4-1 turn in the reverse of install sequence
then install in the install sequence tightening to the 1st pass torque value
after all are replaced do the next 5 stages and do 120 deg on the final one (spec is 90 deg)...

drain the coolant
use a barrel bore tool with wool swab to clean the holes well
pull the plugs
vaccum the cylinders out when done

in reality though, if I have a failure I'm going to try and make a deal with MB
the apportioned cost ratio depending on when it happened
and regardless have it done with heads off and new gasket(s) and probably lifters

I personally believe the failure rate will be an order of magnitude below 1% so I'm not worried about it, if it happens, I'll deal with it

roadtalontsi

My biggest issue with one bolt at a time is I cant stand reusing gaskets/o-rings. I've had too many bite me in the *** that appear to be or were functioning just fine. Im sure one bolt at a time works if your not consuming coolant. However, considering most of the affected cars are 50k+ miles going on a few years theres always that chance for the head gaskets to start seeping externally as well, maybe not that instant or months away but a year or 2 later.... Last thing i'd want to do as a professional or diy'er is spend a good day + on a job only to have to re-do it again. As i've always preached with anything i've done. Do it right or do it twice. The torquing sequence is a nice a workout on these engines - you cant help but think if this one last 90* is necessary and if the bolt is about to snap lol. Anyways to each's own.

skaarlaj

I wouldn't bank on any of this, but if these head gaskets are MLS, I'd try this 1 bolt replacement without hesitation, especially if you didn't have any compression or fluid leakage. I'd try it on my car.

skaarlaj

o

b16

If people (Merc63) on this forum have had success already on this motor doing it 1 at a time, I say go for it.

I did this method in my 4G63 in my Evo8 which saw 40psi of boost regularly after that for 60,000 miles without any issues. Just remove cams, remove 1 bolt, replace, torque, going in reverse sequence.

On the internet you'll always have the keyboard engineers giving their 2 cents without ever trying it themselves. I'll take experience instead.

Ingenieur

what is a 'keyboard engineer'?
some one who designs HMI?

reverse order?
so start at the ends and work towards the middle?
and only loosen the bolt you are replacing?
that would seem bad, you would constrain any distortion/warping and 'push or squeeze' it towards the middle?
I would think start in the middle and work outwards giving a bit extra to each bolt replaced (the MB spec'ed install sequence)

I posted the sequence and diagrams earlier

I'll take education tempered by experience over seat of the pants BS

Abs63

Hey guys,

I picked up my 2009 C63 about a month ago. Ive been getting low coolant message since my 3rd day of ownership. I've had to add coolant twice so far.

I spoke to the dealer and they quoted me $3900 plus tax to replace the gaskets and bolts. Not under warranty.

I did a bit of research throughout the forum but i would still like to ask other owners who have knowledge of this issue before I spend all this money. Would it be wise to get the work done now? Is it too late at this point to do it because of potential damage caused by the lost coolant?

Thanks

DuaneC63

First Read the Sticky on this above
The reader digest version:
Park the car and have it towed to the dealer for the repair. If you keep driving you'll end up with hydro-lock and grenade the motor ($40K plus or minus)
The price of the repair is normal but depending on how many miles you have on the car, MBZ might kick in a few bucks. If you have higher miles, consider having a value job done while the heads are off. You will get new lifters with the repair but have the cams checked. They may also be worn. Keep all the old parts. Since you are paying for the repair MBZ cannot keep the parts under the terms of a warranty claim.
Legal issues. Don't bother pursuing MBZ they have an army or lawyers you can't afford to fight with however the previous owner my not have clean hands:
If he had affirmative knowledge that "the car" (not just some C63 cars) had a head bolt/gasket leak at the time of sale, you may have grounds for legal action. Affirmative knowledge would be a diagnostic report from either MBZ or an independent repair shop of the condition. You will have to get these documents in discovery unless you specified in your sales agreement with the prior owner that he turn over all books and records. If he did not, he has committed a fraudulent act and opened himself up to punitive damages.

Abs63

Thanks for your response Duane

I have 61,000 miles on the vehicle currently. I purchased it at about 59,000 miles. To my knowledge the dealership i purchased the vehicle from wasn't aware of the issue. But i do believe the Mercedes dealership that owned the vehicle before them did.

The sales rep told me the car was purchased from MBZ. I hadn't seen the carfax that i asked for.. my mistake. Later i found out they purchased from an auction in PA. Put there by a Mercedes dealer in PA.

I've read that MBZ will pay half of the cost to repair vehicles that have this issue. Is this something i should talk to my SA about or call corporate MBZ?

Also, I've seen a thread about lifters failing after getting the head repaired. Is this something they already replace or is that additional?