[W126 Coupe] Timing chain and lubrication maintenance note...

[Alexander Hochhausl]

Ouch, that it horrible - Ok, I'm going to have nightmares tonight. But
honestly I would think that there must have been some advanced warning
that something was wrong (like running on 7 cyls)? 

I have almost 160K miles. I changed valve cover gaskets ~ 1 year ago,
and the cams looked beautiful (as much as I can tell). The motor runs
and sounds great, but I have been thinking about doing a chain,
tensioner & rail job for a while.

Anyone know about how much I am looking at in parts, and approx. amount
of time it takes to do the job? (I'll do it myself - no issue with
that). Any special tools needed? I know, parts cost << $ than a motor,
but I'd like to get an idea. $400, $500?

If the cam lobes look good, as they seemed to me, I don't see a reason
to replace them (lifters, valves, etc). Maybe valve seals - but I don't
notice any oil burning. I know, prevention costs less than replacement,
but what level is really needed.

What kind of life do you guys (and gals) out there have on your motors
with what level of maintenance/rebuild? 

Thank You,

Alexander Hochhausl, PE
Tel: 516-909-3794


-----Original Message-----
From: mbcoupes-bounces at mbcoupes.com
[mailto:mbcoupes-bounces at mbcoupes.com] On Behalf Of Josh Allen
Sent: Thursday, January 24, 2008 5:35 PM
To: Mercedes Coupes Mailing Lists
Subject: [W126 Coupe] Timing chain and lubrication maintenance note...

I just started thinking that this might be useful to share with you all.

http://www.flickr.com/photos/hey_allen/sets/72157603726218117/

For those who would rather save a little money on timing chains, regular

oil changes, or even the $15 worth of oil distribution clips on the 
cams, take a look.
This happened to the prior owner of this car, who was happily driving 
along on a surface street.  He said he started to hear a little rattle 
like his exhaust was bumping something, and from what I understood from 
him, about a block later the car stopped.
Pulling the oil fill cap revealed a dry cam with little flecks of gold 
colored bearing material dusted about.  Pulling the cover found the oil 
tube that was photographed alone.  Thinking that the oil fittings had 
failed, I started to plan repairs to the right side, but wanted to know 
the condition of the left while I was checking.

Pulling the left cover revealed the true wreckage that the prior owner 
had inflicted.
Apparently the timing skipped and allowed one of the rear pistons on the

left side to meet the valves, punching up and breaking the cam bearings.

When the cover started to clear the head, the remains of the front oil 
clip fell out, along with a section of the middle bearing journal, and a

rocker.  Once the over was all the way off, there were found to be two 
more rockers off their seats, one wedged between the spring and the rear

cam bearing block.

Currently this car is sitting, waiting on a replacement engine coming 
this way, at which point that engine (with new chain, tensioner, rails, 
and assorted other bits...) will be headed into the car to get it back 
to playing on the roads.

I can gladly say that I didn't do this, but I hope it can be a little 
warning to someone who might otherwise be a little tempted to let the 
chain maintenance slide 'just a little longer', and prevent heartache on

their part!


-Josh
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