W210 E200 Camshaft Broken/T Chain Tensioner

[molly]

It is with great regret that I had not visited this forum before I changed the head gasket on my 1996 E200.

Took the head off no problems - pulled the pin in the head to allow timing chain guide forward - set the timing and all that good stuff.

Put the head back on - new head bolts - torqued to the specified torque ..dwell angles etc etc.

HERE WAS MY DOWNFALL

Installation of the Timing chain tensioner - I inserted into the timing cover without realising what I was doing was to turn out to be catastrophic.

Assembled all the parts back together filled with water first to flush the cooling system - Started her up - Off she went first time - waited until she got warm and then this whirring noise appeared incresed and decreased with engine revs and passed no remarks as it was not all that bad.........Incidently I also changed the mini shock that is attached to the tensioner for the serpentine belt because it was noisy and hinted to myself that possibly the whirring noise was there before but hadnt noticed because of the racket the tensioner was making...........What a mistake - Car only done 10 miles when the camshaft broke on the inlet side of the head shearing of about 7 teeth on the camshaft sproket and damaging the head. It also bent 12 valves.

All of this because the tensioner was not set correctly. Before I took the Head off I Rang the Local MB dealer and talked to a Mechanic just to be on the safe side and I asked if there should be anything I should pay special attention to and I have to say I did mention the tensioner to him and the response I got was..... Oh you will have no problems - everything is straight forward.......This information was misleading hence the problems I have now.


Im currently on the look out for a second hand head with camshafts attached

I would like to have some advice as to how the tensioner should be set. It has a large nut and a allen key head as well at the same end - its in the centre of the nut basiclly.

Thanks and sorry for ravelling on - Im so Peeeeeeeeeeeeeeed OFF !

 

[C220GJS]

Sorry to hear about your problem.
The camshaft tensioner must be fully dismantled after removal(note the plunger can only move in one direction and is pushed out towards the front of the tensioner then reinserted at the hex end);once the camchain is in place, the tensioner body(large hex)is screwed fully into the crankcase ,then the other parts are fitted into the body and the endcap(allen head) replaced,with difficulty against the pressure of the spring.See here;http://www.detali.ru/cat/oem_mb2.as...417717.418&CT=M&cat=19K&SID=05&SGR=045&SGN=02 .
If it is not done this way the timing chain is overloaded and will break the camshaft as you found.
This has been covered many times as it is a common mistake, do a search and you should find previous posts on the subject, above all your so called MB mechanic should have known to advise you.

 

[molly]

Many Thanks C220GJS for your reply and your illustration on how the tensioner should be installed.

Currently on the look out for a second hand cylinder head complete with camshafts attached.

I have examined the chain and it seems to be fine - Would You recommend to change - I wouldnt only if I really had to.

Thanks again.

 

[C220GJS]

This would be the ideal time to change the chain if you had any doubts about it's condition, check the chain for missing rollers and the camshaft sprockets for excessive wear or hooking on the teeth signifying chain stretch, but unless the engine has done well over 150k mls or been neglected of oil changes this should not be an issue.

 

[molly]

Thanks again C220GJS for the reply. The engine oil was changed without fail evert 10k by myself so I thing the chain is in good enough nick and all rollers are in place.

Went on the hunt Today for a second hand head complete - had not much look - I was told that a C180 cylinder head of the same Year 1996/97 will fit my E2000 96 - was also told that a C200 of the same year is also compatable - Is this true ? Does any one know if either head is compatable bearing in mind that mine is the non variable timing head - this I also learned Today.

 

[television]

You can check all of the engines out here, and the differences

http://www.detali.ru/cat/oem_mb0.asp?TP=1

 

[molly]

Thanks for that Malcolm.

Can someone tell me what these numbers mean - I know that 942 is part of the engine number but the numbers after that Im having trouble understand e.g 10/50,20/60 022019 etc etc.

*861 UP TO ENGINE:
942 10/50,20/60 022019 EXCEPT
VEHICLES WITH CODE 807
942 12/52,22/62 016444 EXCEPT
VEHICLES WITH CODE 807

There are a lot of variances in the 942 engine - Its just to understand what they are

Thanks:???:

 

[OlafMaxwell]

Chain

I must admit if I had an engine apart like this I would regard it as a false economy to reuse the chain. 150k is a lot, I would replace it if it were my own car.

 

[television]

Thanks for that Malcolm.

Can someone tell me what these numbers mean - I know that 942 is part of the engine number but the numbers after that Im having trouble understand e.g 10/50,20/60 022019 etc etc.

*861 UP TO ENGINE:
942 10/50,20/60 022019 EXCEPT
VEHICLES WITH CODE 807
942 12/52,22/62 016444 EXCEPT
VEHICLES WITH CODE 807

There are a lot of variances in the 942 engine - Its just to understand what they are

Thanks:???:

Go to the bottom of the page and it tells you what the numbers are, often from xxx

 

[television]

I must admit if I had an engine apart like this I would regard it as a false economy to reuse the chain. 150k is a lot, I would replace it if it were my own car.

I agree Olaf not worth all that work with replacing it and 150 is the max normally