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  #16  
Old 12-13-2009, 05:13 PM
latief's Avatar
1993 300E 2.8- M104
 
Join Date: Aug 2009
Location: Gainesville, FL
Posts: 518
Ok,

So how can i know for sure i have a streched chain? something has to be off in the setup causing both me and the previous tech to put it together in the same manner.......what about the intake came itself with the cam advance gear? Could something be wrong there?

thanks for the feedback on this ......

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  #17  
Old 12-13-2009, 07:15 PM
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1993 300E 2.8- M104
 
Join Date: Aug 2009
Location: Gainesville, FL
Posts: 518
I am not the only one with this problem

M104 - Camshaft/Crankshaft Position Discrepancy??

I know there was another one i saw, i will look for it

Edit: M104 timing

See post 5, same problem
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Last edited by latief; 12-13-2009 at 09:51 PM.
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  #18  
Old 12-14-2009, 01:24 PM
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Join Date: May 2005
Location: San Diego
Posts: 38
cams

Latief,

That guy's cams lined-up with each other.
The variation on the harmonic dampener (crankshaft) shows chain stretch. In his case that was 4 degrees.
Because there is such a short distance between the cams, their positions relative to each other should be almost dead-on even with some chain stretch.
10 degrees is just too much to be chain stretch. And based on your pictures, I can see that one cam has rotated much more than the other.
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  #19  
Old 12-14-2009, 02:05 PM
latief's Avatar
1993 300E 2.8- M104
 
Join Date: Aug 2009
Location: Gainesville, FL
Posts: 518
so what do you advice me to do ?


This is how i did this for like 10 times before sealing it off...

1-crank at TDC (chain loose and off the exhaust gear)
2-cams at head surface level using drill bits for reference
3-rotated the cam -free of chain- using they advance/retard mechanism counter clockwise until it stopped.
4-pulled the chain really hard on the right side to get it over the intake cam. chain always seemed to short to go on the next sprocket pin, and too long for the previous pin causing the slack....
5-muscled with the exhaust cam to get it back on correctly. seemed to be some slack between exhaust and intake cams also
5-no way to remedy that slack no matter what i tried, hence the problem!!!
what else could be done? everyone else gets this straight forward process correctly, except their is something preventing me from doing this correctly. and i cannot figure out why no matter what !!! i am fairly analytical handy and intelligent (i think!)


I am going to take the front cover off, and see what could be done. i am expecting something wrong with my chain advance-retard mechanism maybe causing some slack in there? no need for a new chain in your opinion?

thanks.,
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  #20  
Old 12-14-2009, 02:25 PM
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Sequence

Latief,

Thanks for posting that sequence.

First of all, you should be rotating the adjuster clockwise (retard position)before installing the chain. by rotating it counter clockwise, you are advancing the adjuster.

Second....are you saying that with both dowel holes perfectly lined up with the top surface of the head, and the chain fully installed, there is signifant slack between the two cams? ....This should not be....

Keep in mind that the valve springs will force the cams to turn off of their markers. But as long as the tensioning of the chain corrects their positions realtive eachother, you will be fine. You really have to visualize this part in your head. (I had a hard time at first)

Try to rotate the crankshaft approximately 5-10 degrees counter-wise to allow more slack to install the chain. Then snug it back-up after the chain is installed to remove the slack from the driver's side of the engine. Then install newly re-inserted tensioner and rotate to check for accuracy.

It will be hard to get the 0IT mark on the harmonic balancer to line up while the cams are perfectly aligned, but this will be an indicator of the stretch of the chain. The important part is that the cams line-up almost perfectly with each other. When they are aligned, look down to check the harmonic balancer. If you are less than 3-8 degrees off the 0IT mark, you are probably properly timed. If your variation is more, you are probably one tooth off.

To start off, just remove the upper timing cover and rotate the engine by hand/starter until the exhaust cam dowel hole is perfectly lined-up . Then check the intake cam to make sure it is also lined-up. If these are not currently lined-up with each other, then you will know you need to re-time.

Last edited by dhaghighi; 12-14-2009 at 02:43 PM.
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  #21  
Old 12-14-2009, 02:36 PM
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1993 300E 2.8- M104
 
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Location: Gainesville, FL
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that was a typo on my behalf, i rotated the cam timer counter clock-wise, sorry.....

there was some slack between the two cams before i rotate and tension. once i rotate and tension, then the slack is gone....

I guess i will have to take this apart and try your techinqe ...are you sure it is ok to go counter clock wise on the crank? man that is alot of work to get that front cover back on.....

no need for a new chain? i would hate to change that and find that the situation remains the same....

what baffles me with all this is that the tech who did the head gasket before (and i am assuming it was done by a tech) could miss something like this....why am i the only person who is having a problem with this?

Edit: I will take the cover off soon. I will update this...

thanks,
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  #22  
Old 12-14-2009, 02:48 PM
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cam adjuster

Yes....counter-clockwise is incorrect Clockwise would be correct.

This is your main problem with timing the engine. When you rotate for the first time, the intake cam adjuster is moving before it engages the cam.

The engine rotates clockwise, so just visualize for a moment the way the crankshaft pulls on the chain up-to the intake cam. You have to adjust the adjuster clockwise so that there is no movement in the adjuster during your first engine rotation.
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  #23  
Old 12-14-2009, 03:08 PM
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1993 300E 2.8- M104
 
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Location: Gainesville, FL
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checked my records since it has been a while....

sorry for the confusion, it was clockwise

I will have to take this apart and get this right....

thanks for the feedback and help on this !!!

Edit: come to think about it, i am not sure anymore maybe i was doing this backwards. i will kick my self if that is the case... i will have to check this again to see......
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Last edited by latief; 12-14-2009 at 03:21 PM.
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  #24  
Old 12-14-2009, 07:47 PM
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'93 300E 2.8
 
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How about this: Would it be easier to break the chain before doing this? It would make this job physically easier because you aren't muscling that friggin chain over the sprockets. You could line everything up and just lay the chain nicely over the sprockets and then install the new master link. On the downside, it would add one more step to the job and you would have to get the new link and peen it on (or use the special tool).

That is how I did it because I was installing a new chain and guides. I set the intake cam adjuster clockwise to full stop, set the two cams with drill bits, set the crank pointer just as the manual shows, looped the chain over and bingo, it was right on. All the slack was on the passenger side. I next installed my tensioner. Next step is to rotate the engine to make sure it's all together right but first I have to get the upper timing cover back on with the top chain guide in place.
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  #25  
Old 12-14-2009, 08:00 PM
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1993 300E 2.8- M104
 
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Quote:
Originally Posted by 73Elsinore View Post
How about this: Would it be easier to break the chain before doing this? It would make this job physically easier because you aren't muscling that friggin chain over the sprockets. You could line everything up and just lay the chain nicely over the sprockets and then install the new master link. On the downside, it would add one more step to the job and you would have to get the new link and peen it on (or use the special tool).

That is how I did it because I was installing a new chain and guides. I set the intake cam adjuster clockwise to full stop, set the two cams with drill bits, set the crank pointer just as the manual shows, looped the chain over and bingo, it was right on. All the slack was on the passenger side. I next installed my tensioner. Next step is to rotate the engine to make sure it's all together right but first I have to get the upper timing cover back on with the top chain guide in place.
when you took yours apart, was it on the mark to start with?

I will take this apart. if nothing changes, i will order a new chain and do this....how did you break the old chain? and do you need a special tool to install the new one ?

thanks,
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  #26  
Old 12-14-2009, 08:10 PM
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Quote:
Originally Posted by latief View Post
when you took yours apart, was it on the mark to start with? thanks,
Ugh, sorry - I didn't make note of it. I have read your other posts on this and have wondered whether mine was spot on or no. I was taking mine all apart so there was no need to mark the chain or sprockets (as the manual shows) or to check for proper TDC and timing.


Quote:
Originally Posted by latief View Post
...how did you break the old chain? and do you need a special tool to install the new one ? thanks,
This is all in the manual. You use a Dremel or die grinder to grind the peen ends off the pins of one of the links, then pry the cover plate off, and then that one link falls out. For the new chain, the manual shows the use of a special tool to peen over the new pins but it can be done with two hammers or a hammer and a backup of some kind to peen over the twp pins. There is a guy here on the forum that will rent you the tool for like $15 plus the shipping. I used a hammer on one end and a sledge as a backup on the other end of the pin. You could also use a hammer and punch to stake the pin ends but you will need a third hand to hold the backup. The two-hammer trick was taught to me by a MB indy mechanic.
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  #27  
Old 12-14-2009, 08:18 PM
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1993 300E 2.8- M104
 
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Location: Gainesville, FL
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How did you remove the crank pulley? That is really what prevented me from changing the chain and guides in the first place( well in addition to everyone swearing that the m104 chains don't stretch)

did the (timing cover first- guide pin later trick) work for you?
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  #28  
Old 12-14-2009, 08:21 PM
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I had another thought on this. If you recall in Steve Brotherton's write-up article on this job, he says it is a common mistake to reassemble the timing with the advancer in the wrong position and he says the car will run pretty well in this state but it will set a code. Is one of your codes this same code? Maybe go back and read that part of Steve's article again.

I feel for ya bro, man that SUCKS to have to go back in and do this again... wer'e pulling for ya if that helps any, moral support and all that from your fellow-suffering W124 brethren. I think this job is what James had in mind when he wrote "Consider it pure joy, my brothers, whenever you face trials of many kinds, because you know that the testing of your faith develops perseverance..." he he he
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  #29  
Old 12-14-2009, 08:31 PM
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'93 300E 2.8
 
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Quote:
Originally Posted by latief View Post
How did you remove the crank pulley? That is really what prevented me from changing the chain and guides in the first place
You don't need to remove the crank pulley to replace the chain. To put in the new chain, you connect the new chain to the old one and pull it through by rotating the crank. It's all in the manual. I can send you those sections of the manual pdf if you need it.

The pulley comes off with a regular harmonic balancer puller, free rental tool, like from AutoZone. BUT you have to get the big 27mm bolt out of the crank first and that bad mofo is torqued on there to 400 N-m. So you have to get a stout breaker, a cheater bar, and a device to lock down the crank.

As I said if all you are going to do is change out the chain then you don't have to pull the harmonic balancer. If you are going to change the chain guides too though then yes you have to do this and pull the front cover and then you are in for some work.

[QUOTE=latief;2360803]How did you remove the crank pulley? That is really what prevented me from changing the chain and guides in the first placeaddition to everyone swearing that the m104 chains don't stretch)

Quote:
Originally Posted by latief View Post
did the (timing cover first- guide pin later trick) work for you?
Well I printed your post and promptly walked out the door without it. Got home and couldn't remember what you said to put in first so I put the pin in. DUH now I have to pull it out again...
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  #30  
Old 12-14-2009, 08:44 PM
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1993 300E 2.8- M104
 
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Location: Gainesville, FL
Posts: 518
Quote:
Originally Posted by 73Elsinore View Post
I had another thought on this. If you recall in Steve Brotherton's write-up article on this job, he says it is a common mistake to reassemble the timing with the advancer in the wrong position and he says the car will run pretty well in this state but it will set a code. Is one of your codes this same code? Maybe go back and read that part of Steve's article again.

I feel for ya bro, man that SUCKS to have to go back in and do this again... wer'e pulling for ya if that helps any, moral support and all that from your fellow-suffering W124 brethren. I think this job is what James had in mind when he wrote "Consider it pure joy, my brothers, whenever you face trials of many kinds, because you know that the testing of your faith develops perseverance..." he he he
Yeah, that was all the clock-wise, counter clockwise discussion above....i will have to check this again just to be sure, but i am fairly confident i did it right since i set the timing like 10 times......still, i will give it a shot because i have not been impressed with the car performance, and the smell is really bugging me, besides dhaghighi gave me some good ideas, so i hope it will end up right this time.....

thanks for the support, the only thing bugging me is having to reseal that damn cover again. and the only thing worrying me is going through all this for nothing and being stuck with the same problem......

as for the crank bolt, are you serious about the 400 NM ? I did not know that such number existed (at least in the car world)..yeah that is beyond my abilities considering where i work, and the tools i have....if i can't get the timing right, i will just change the chain and see what happens .....

thanks,

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