Karl901

Just replace 1 bolt at a time. Never took head off!

Critter

Karl, just what did you use to hold cams in place upon removal, was timing set to 40 degrees prior to removal or just what was your process, if you would please outline your procedure, many would appreciate the input.

Karl901

Nothing moves if you do 1bolt at a time.

Critter

So Karl, you say that you did not have to remove the cams to change out the bolts, just asking right now have no reason to remove the valve cover to look

Karl901

I just asked Renntech why not just remove and replace one bolt at a time,
and they did it. All they told me was they had to lower the coolant level.
No studs, just new MB OE bolts.

Critter

Thanks Karl, was under the impression that the cams had to be removed to gain access to the bolts, so you are stating that Renntech was able to change out the bolts without this additional work. If this is the case could be an interesting winter up here in Canada!

Mort

Believe the cams come out to change the head bolts.

Merc63

Cams have to come out.

Need a mb tool to hold the one adjuster and a 4mm bolt to hold the other cam adjuster. Also need a mb tool to hold both cams in the proper position so they can be bolted back down.

Critter

Thanks Merc, that was my original belief, if it was that easy every one would be changing them out. Did you purchase these tools online or have you got a source?

Merc63

Bought them from dealer. Simple tools nothing crazy

Critter

Would you share the part numbers for the tools you purchased from MB!
Thanks in Advance.

Merc63

Read the thread, its already been discussed.

Critter

Merc, have been following along and contributing as I also own 2 of these vehicles in question. I seen the tools a while back you stated but was uncertain as to where you got them, E bay or ?. I have no issue with the one at a time method or complete removal of the head and new head gaskets as a second option. If it was not for the cam scenarios, then I would have already changed out the bolts as I know the way to the tool box. Thanks for your continued support of this thread. So far so good neither car burns oil or uses coolant although they like gas and lots of it,

Merc63

Removing the cams seems hard but is quite simple. You just need to understand how they work with the adjusters. Main this is locking the adjusters in place and having the tool to hold the cams in position whike you bolt them down against the valve spring pressure.


also putting marks on cam gears to make sure they go back in the right spot.

Critter

Thanks again Merc63, SOHC would be a breeze but with two cams forcing different valve buckets down I can see it being a PITA without the tools if next to impossible. Just what kind of money is a person looking at for the purchase of the cam tools? Yes also timing is very critical and a one shot deal. One part of the engine not making sense is why there is no key or some other method to hold the cam adjusters to the cams other than bolt torque, could you comment on this? I believe this is also a TTY bolt.

Merc63

Cam adjusters are held to the cam by a big bolt yes. There are two gears that drive the cam adjuster, one Is under pressure to take up the gear lash. You must lock the gears together and thats what the MB tool and M5x8 bolt do. They go into both gears and hold them in place. Then you can just pop the cams out and set them aside.

once the engine is rotated to 40degrees. The cams have 2 parallel sections machined flat where you put the other MB tool that holds both cams perpendicular to the head. This allows you to remove and install the cams in the right position. I dont see how it would be possible to install them incorrectly with this tool on them as they are held at 90degrees off the head.

Without the tool you could install them back if you made markings, but good lucky because you are trying to bolt the cams down against the valve spring pressure and some lobes are hitting the tappet at an angle. So as you bolt the cam down without the tool, the cam will start to flop around.

Here is a pic with the tool on the cams. Its just a black piece that holds them both and bolts to the head.



When you remove the cams, you dont need to remove the adjusters.. Just lock them in place and remove cam with adjuster. The tool to install the adjusters isnt needed since you arent removing them.

Just looking at these pics now I found and I see you posting there.. That is very disheartening to see that tappet and cam damage, something else to worry about now LOL. I dont think the suggested oil change intervals is helping hah.

https://mbworld.org/forums/w211-amg/...y-lifters.html

Merc63

http://www.mercedes-amg.com/privatel...2&d=1353352595

Here is a PDF that shows how the cam adjusters work. The bolt holds the rotor. The rotor holds the adjuster that floats on the cam. As oil is shot in, the rotor either moves CW or CCW as the cam spins to retard or advance the timing and change duration between the intake and exhaust.

Merc63

Im installing head studs and SLS valve buckets this weekend in a members car. Ill ask if he minds if we take some pics and maybe Ill write a little DIY.

Critter

Thank you Merc63, this information is greatly appreciated by myself for sure and also to other members. Any pictures during your next adventure would also be appreciated as well as a small writeup, bullet form would work to ease your work. The 4mm bolt to secure the cam adjusters, as well as the timing, is 40 degrees marked on a stock pulley. Again thank you for your time.

motoman

Merc, Thanks for your charity, especially since we know you need tires for "baby," A while back you showed a cam tool with ?Japanese? characters . How does this fit into your overall toolbox, a duplicate of the MB tool? I could not copy that pic for some reason.

Please stay with us on the cam lobe vs lifter pressure during assembly. In another life I tore down 1600 Lotus engines which had cast (brittle) cam shafts. It was possible ( and happened once) to snap the cam during the tightening of the bearing caps. Are the C63 cams strong (billets)? Are the valve spring pressures high?

Do I hear the readership strong on trying the one-at-a-time replacement method? Any such engines with successful high mileage? thanks

Merc63

Weistec arp studs are torqued to 110ftlbs.

when I first install them I torque to 80 ftlbs. After all the studs are in at 80 ill go over them and torque to 110ftlbs as per the spec.

the numbers I list previous were wrong. I couldnt remember exactly what we did that time. I just went over the weistec arp stud instructions and thought I should correct that.

Mort

Thanks Merc63. I am planning on doing this as well this winter or next. Maybe next winter as I am doing MBH headers this winter.

EC C63

Last week, witnessed the “check coolant” and the “top off coolant” warnings. Stopped driving the car, went to the dealer and had to present the TSB to substantiate my concern over the head bolts. Thanks to Bud Wilkinson for posting the TSB on post #479.

I took the TSB along with my Data Card (to show I was in the bad head bolt range) to the dealer. My MB dealer is a regional sales and service rep and therefore, had to make a call to the dealership’s national “home office” for more clarification. Since the TSB is a “LIxxx.xxx.xxx” version, learned it was recognized to be a “Local” version; vice a “GExxx.xxx.xxx,” which would mean a “Global”distributed TSB. It was further explained to me that there is no recall over the head bolts for the M156.

I now have an appointment to have the car checked under warranty on the head bolt issue, now that the dealership acknowledged the “LI” TSB. If I didn’t have the TSB, it would’ve been a hard sell. So, definitely thank you B. Wilkinson. It helped me get the ball rolling in what I think is the right direction.

Here’s my recommendation for anyone who is concerned of an engine block leak for those M156 engines that are in “the range.” They may not be catch all indicators, but may help. Check the coolant reservoir with a dab of white paper. If oil has made its way into the coolant system, dabbing the white paper in the reservoir will reveal the oil as it should eventually rise to the top in the reservoir. You could also check for a mix of coolant into the oil with a thorough oil dipstick check. Even if you haven’t received the warning and your engine is in the range of the faulty bolts, do these checks periodically or closely monitor your coolant level as preventative maintenance. You may also want to press the issue with your MB dealership, using the TSB as a justification, rather than waiting for the failure or the failure occurring just when you’ve hit the point of being outside your warranty.

Luckily, I’m still within my warranty and if the check-up is revealing, the service should be cost-free to me. I did ask about getting the SLS lifters/tappets if the head bolts are replaced during the engine rebuild. The SA was unsure, noting they would have to use whatever MB dictated by part number.

Does anyone know if the SLS lifters are automatically used; previous M156 lifters precluded? Part number for the new ones?

Thanks...

Merc63

Pressure test should show a leaky head gasket.

Mgsafety

Update: Finally got some follow up info. Spoke face-to-face with Service Mgr at local dealer. His opinion was that MBUSA would not likely participate in my repair. Also, did some creative writing and finally got my MBUSA case mgr to give me some ballpark idea of any potential participation. She told me that "if any" participation from MBUSA, I would be looking at 10-15% tops, "IF", no guarantees in participation.

The dealer would have needed me to put the engine back together and add fluids back before I were to bring it back anyway. Cost of putting it back together and bringing it to dealer would not be cost effective.

So, my error, brought it to my trusted local indy shop first, HOWEVER, my opinion, I would have "potentially" received up to 15% discount (best case scenario) off of high dealer repair costs, possibly not even saving me any out-of-pocket expense. Additionally, my opinion is that my indy shop will do higher quality work than dealer.

So this is what I keep telling myself to make me feel better about the whole situation.

Disappointed in MBUSA for lack of support of their engineering failure.

No total cost of repair yet. Still in shop. Expecting to get it back next week.