W203 M271 Ultimate Timing Chain DIY
This is essentially Killerpancakes method mentioned in joggers thread in page 9 I believe.
"After removing the tensioner, the time comes to build up some courage and break the old chain. To break and rivet the chain I had a tool designed for a larger type of chain. I was able to make it work with a significant amount of MacGyvering, but I would HIGHLY recommend having a proper tool for the type/size of chain here. I then very loosely/temporarily riveted the new chain on to the end of the old one and loosely fished it through. Do NOT just pull the old chain out - you definitely want to use it to fish the new chain through, otherwise the lower timing chain cover would likely also have to come off to install the new chain around the crank."
That was quoted from his method.
Correct me if I am wrong, but Mercedes procedure uses a special tool which does not allow the chain to skip while you are feeding the new chain through, i.e. the cams are rotating and valves are operating.
Correct me if I am wrong, but Mercedes procedure uses a special tool which does not allow the chain to skip while you are feeding the new chain through, i.e. the cams are rotating and valves are operating.
At the end of the day assuming no bent valve or scuffed pistons, as long as crank is at 0 deg and cam gears line up to their respective marks, timing should be dead on right?

The Best of Mercedes & AMG
https://mbworld.org/forums/c-class-w...hain-pics.html
https://mbworld.org/forums/c-class-w...hain-pics.html

He spun it in front of me and the lines all marked dead on. What happened is beyond me. I will update with pics soon to follow once she's fired up tomorrow.

so what did the mechanic do different to get it to spin? did he redo the chain or was he able to spin it without doing anything?
In any case glad it's all sorted now!

I haven't read the procedure but it sounds like you - and the usual practice is to - do everything with cylinder #1 at TDC so you should line up the degree wheel on TDC and make sure that piston #1 is at TDC. That's probably when your cam marks need to be on their marks, too.
My guess is that somehow, you turned the crank 180 degrees.

The TDC mark on the balancer will be the same position for the pistons all the time. What causes it to be either on the exhaust or intake stroke is the position of the cams which with the marks lined up would be TDC on the compression stroke. For it to have been 180deg out then the cams would have been out of alignment.
With the chain connected one revolution of the crank will be 1/2 revolution of the cams. This was more critical on older engines with a distributor where it could be put in on the wrong stroke of the piston thus being 180degrees out. These engines with distributorless ignitions can't happen plus the marks for both the cam and crank were aligned so had to be at TDC...that's what doesn't make any sense.

It will be interesting to hear what the wrench did to get it to line up properly!
I remember reading something like that, when people had the timing 180 degrees off, but didn't know that the pulley actually indicated TDC twice...
I remember reading something like that, when people had the timing 180 degrees off, but didn't know that the pulley actually indicated TDC twice...
It will be interesting to hear what the wrench did to get it to line up properly!
ncmudbug I'm not sure what was wrong, but I was truly dazzled when I showed up and he rotated the engine in front of me while the lines all aligned... without changing the crankshaft pulley. He also goes to note that these engines at the 0 degree TDC mark do not mark the top height of the piston. He mentions it has to do with the variable valve timing. He says it is close to 0 degree but not right on it.


---oops just saw your last post ^^^ I wouldn't worry about any damage though sounds like you stopped before anything would have happened
Last edited by krazzdav; Oct 8, 2014 at 01:37 AM.

---oops just saw your last post ^^^ I wouldn't worry about any damage though sounds like you stopped before anything would have happened
. We kept on cranking and it just won't start, there are no metal noises at all, it just won't start. He checked codes and none are being presented, checked fuel pressure and its good.
It seems as if its out of timing, it tries to start but it just won't catch. After much convincing he agreed to pull the crank pulley tomorrow and check the guide and the position of the marks of the pulley in relation to the guide on the pulley to check if it has slipped.
I am going to go on a limb here and we all probably knew on here that the problem was the pulley marks all along.
I don't believe any damage has been done in terms of interference, while it cranked it sounded very strong, no metal noises again, just normal starting noise of engine trying to catch but wouldn't.
We shall see where we fall tomorrow.

Couple things.... You don't have to pull the crank pulley all the way off to see if it spun.... just pull the bolt out and see where the keyway is in relation to 0|T and U|T
Did you find out what he did different to correct the "out of time" that he mentioned the first time where you couldn't spin the engine but he could?
Couple things.... You don't have to pull the crank pulley all the way off to see if it spun.... just pull the bolt out and see where the keyway is in relation to 0|T and U|T
Did you find out what he did different to correct the "out of time" that he mentioned the first time where you couldn't spin the engine but he could?

Thats what I meant, he will pull the bolt and see the the relation to the marks.
According to him it was just that my timing marks were off. He specifies that the only way to do it is by locking the cam gears with the mb tool. Maybe he hasn't seen what people have been doing here? maybe once you do what I did which is basically set the timing as if it were a new engine you need to use that tool, Im not sure.
I mentioned to him that everyone on the forum that has done the job has specified that at 0 degree mark on pulley, 1st piston should be at the highest point. He mentioned that not always is the case on some engines, and he believed this was one of them, but after the no go today I assume he might be veering this way now since it won't start...




