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

[Carl Hansen]

The old question of what came first, the chicken or the egg.
The plastic connectors likely melted because the bearings overheated.
The bearings overheated because they were starving for oil at one point.
Carl


----- Original Message ----- 
From: "Chet Hwilka" <chwilka at comcast.net>
To: "'Mercedes Coupes Mailing Lists'" <mbcoupes at mbcoupes.com>
Sent: Friday, January 25, 2008 6:53 AM
Subject: Re: [W126 Coupe] Timing chain and lubrication maintenance note...



> I'd guess there was either blockage in the oil feed to that head

> (headgasket, debris, whatever) or the plastic connector to the cam-oiler

> pipe broke.  That pipe uses plastic joints to connect the pipe to each of

> the cam tower bearings.  Which feed the cam bearings and squirt the rocker

> arms with oil.  It would not take long before the cam bearings overheat 

> and

> seize up stopping the timing chain.

> http://mywebpages.comcast.net/chwilka/images/Head%20R-R/OilPipe150.jpg

>

> http://mywebpages.comcast.net/chwilka/cylinder_head_removal_and_replac.htm

>

> Chet

>

>

> -----Original Message-----

> From: mbcoupes-bounces at mbcoupes.com [mailto:mbcoupes-bounces at mbcoupes.com]

> On Behalf Of Carl Hansen

> Sent: Thursday, January 24, 2008 11:19 PM

> To: Mercedes Coupes Mailing Lists

> Subject: Re: [W126 Coupe] Timing chain and lubrication maintenance note...

>

> This problem is not caused by a worn cam chain.

> There's no way a worn chain can cause that kind of damage. At 150,000 

> miles,

>

> no way.

> That the engine has been running without oil for whatever reason.

> No doubt about it.

>

> Carl

>

>

> ----- Original Message ----- 

> From: "Carl Hansen" <c.c.hansen at cogeco.ca>

> To: "Mercedes Coupes Mailing Lists" <mbcoupes at mbcoupes.com>

> Sent: Thursday, January 24, 2008 8:48 PM

> Subject: Re: [W126 Coupe] Timing chain and lubrication maintenance note...

>

>

>> How many miles on this car?

>> Carl

>>

>> ----- Original Message ----- 

>> From: "Josh Allen" <heyallen at null-ptr.net>

>> To: "Mercedes Coupes Mailing Lists" <mbcoupes at mbcoupes.com>

>> Sent: Thursday, January 24, 2008 5:35 PM

>> 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

>>> The MB Coupes Website!

>>> W126 SEC Mailing List

>>> Postings remain property of MB Coupes, L.L.C.

>> The MB Coupes Website!

>> W126 SEC Mailing List

>> Postings remain property of MB Coupes, L.L.C.

>

> The MB Coupes Website!

> W126 SEC Mailing List

> Postings remain property of MB Coupes, L.L.C.

>



--------------------------------------------------------------------------------



> The MB Coupes Website!

> W126 SEC Mailing List

> Postings remain property of MB Coupes, L.L.C.