jptaylor

Wonder why my exhaust looks like a club at 2am and I've gotten a low coolant level warning.....

Merc63

Because you're head gasket is leaking coolant into the combustion chamber.

Mort

Serious?

Headbolts?

Cold weather exhaust condensation?

Don't like the low coolant warning with this. Have you checked the level?

I know I really don't have to ask you that.

jptaylor

#3 head bolt on driver side had ripped the head away from the shaft.....Went with MB replacement bolts instead of studs....$160 vs $1000 was a No-Brainer....20 $8 bolts, 1 $110 M156 cam adjuster tool and 14hrs work and problem solved....It was BLOWING white smoke like a cloud, oil like chocolate milk.....Not sure why this is a $5-8k job, I've literally got less than $300 and a busy weekend in the fix

glennhl

Did you replace the head gaskets also for this price?

jptaylor

nope...I had them just in case but considering how these head gaskets are made I can't see how one would fail due to a headbolt letting go unless it was more than one side by side....So the they go back tomorrow

Jasonoff

https://cimg5.ibsrv.net/gimg/www.mbw...f698390164.jpg

Took me a sec to realize those were bolts and plugs poked through a piece of cardboard.

How many km/miles on your odo?

Jasonoff

You may regret that decision. Another member has tried that already and failed. Once the gasket is compromised you likely need to replace it and clean both mating surfaces.

jptaylor

Yeah, I've done disassembly like that for years, a cardboard box just makes really easy to keep up with everything and remember exactly where it all came from....160k and counting...there was no doubt that the leak I had was coming up through the bolt hole and into the center cavity of the head-you could see all the "jellied" foam around the bolt head(guessing that was the coolant being exposed to that level of heat).....we'll see if it holds up, if it doesn't I'll just do it again BUT if it were a rear bolt that broke I honestly don't think you could remove the head with it the car still, there is not enough room as is much less having to clear the rest of the broken shaft to get it up and over

glennhl

If you only had one broken bolt and it was obvious that the coolant was just going through that area, you may be OK not replacing the head gaskets. But normally once the coolant seeps past the head gasket into the combustion chamber you are stuck taking the heads off, cleaning the faying surfaces and putting new head gaskets in place. Keep us informed. And by the way, GREAT JOB!!!! You are a heck of mechanic to do that job so quickly. Did you have the tool to locate the cams when you went back together or is there another way to do this? I'm betting you could make a lot of money doing preventive head bolt replacement on these engines. Do this before the head gasket is compromised and do just one bolt at a time and you are golden.

Seems like we are seeing more and more head bolt failures which doesn't really surprise me because the failure is due to a design error. I'm betting Mercedes already has done a weibul curve and they know when they are all going to break. It's like popcorn popping, some kernels go early, some go at the very end, but in the middle a bunch of the kernels pop. I'm guessing we are still near the very beginning.

550x2

It means you elected a new Pope! LOL

BLKROKT

Nice work dude

jptaylor

ok, that was funny as hell!!!

On a serious note, it is NOT that bad of a job....yes, I ordered the cam adjuster alignment tool and even though I have heard people say you could don't without one I don't see how, and I studied the hell out of it....once you figure out how to use each piece how its intended you realize how ingenious it actually is....and by all means-MARK THE CAMS AND CAM BEARINGS WHERE THEY LINE UP....you don't have to but it will give you peace of mind when your deciding whether or not to put the valve covers back on after staring at the cams for 30min thinking "Is this right? Am is SURE this is right?"... Doesn't matter how you install the cam gear as long as you can get to the locking hole, the segment plate on the front is actually what does the timing fine tuning and the install jig will ONLY align the segment plate in one position.... The cams are slotted on the back end and the piece of flat stock is machined where it will only lock them in place when they are in time-BOOM!!!!

I'll do a synopsis tomorrow for some of the DIY guys....for all those in the affected range that have NOT revised their bolts and have NOT yet had failure I would say take $300 and a weekend and knock that **** out

Alex.currie44

+1 but I admire the effort.

Celicasaur

Reading this reminded me of when I recently rebuild an S62 motor as it's quite similar in some respects to the M156. Timing that thing without a special tool was a horrible experience. I'm guessing the cam locking tool which you used has made the job a lot more bearable....well done

Looking forward to seeing the DIY guide.

jptaylor

Ok, so someone figure this out...I don't believe that my oil cooler fan has ever worked. I always assumed that it ran while engine was running and shut down with the ignition...But NOW it runs, loud enough to be noticeable with engine running but also after I shut the car down...I'm stumped

faz492

My m156 is engine is blowing out white smoke and engine is rough idle and car switches itself off when the revs drop too low...
I'm trying to figure out the issue myself so far with my car

dave2001auto

water. How cold is the outdoor temperature? On very cold weather there will be lots of white smoke. If lots when warm weather, look for internal coolant leak.

Celicasaur

I think we both have a good idea what that is bro...

jptaylor

You have coolant being burned...When my coolant warning first came up that was the only issue...Then after about 5mi of driving I was home so shut it down....Next morning it did not want to crank and when it did it ran horrible...Got 3 misfire codes as well...Shut it down, started it back up and it ran fine but at that point is when it started smoking.....I did drive it 2mi to my shop and it ran fine there, no codes or run issues, just smoke

jptaylor

If it were condensation it would be steam, not smoke...If you watch it steam will dissipate and disappear very quickly, if it is smoke it will not dissipate and drift off in a cloud

Jasonoff

I can't say I had fun doing it though.

jptaylor

Believe it or not I actually did....I love the mechanical side of all things automotive and was amazed at the differences in not only build quality but also the underlying methodology....Plus it was amazing to see that after 160k miles my heads looked brand new...The tappets literally had a mirror finish on them and there was no visible wear patterns ANYWHERE .....On any part

mcsvt

I'll generally tackle anything, but this one I'm not sure. This car seems to find ways to fight me when I work on it. Wavetrac install, damn those snap rings and the intake I guess was easy, but of course a fitting that only comes on the intake was brittle and broke.

Anyway, looking forward to a bit more of your DIY details. '08 with 43k, so far so good...

Jasonoff

Weirdo I am shocked at the single bolt with diamond washer holding the cams in place though. If you noticed in the WIS they updated the torque spec.