[W126 Coupe] Camshaft Snapped! Intermittant Rough Idle -Me too - HELP!

[airedale at sbcglobal.net]

What a shock! Last Saturday I went into the Post Office and left my perfect 
running '91 560SEC idling with my lady friend in attendance. When I came out 
she said the car shook and then started running rough. I drove home with 
this low speed miss but the car could have gone as fast as I wanted on the 
highway. I called my mechanic Monday and took it in thinking some electrical 
or maybe the fuel system was amiss. He immediately isolated the cylinder 
closest to the driver and said it had no compression and thought perhaps a 
lifter had collapsed. I left the car there. He called this morning and said 
the left camshaft had snapped! I went there and sure as if it had been cut 
by a hacksaw blade the camshaft was in two pieces broke just ahead of the 
bearing journal before the last cylinder on the drivers side. I wad 
dumbfounded looking at this 1 inch steel bar that had snapped like a 
matchstick. He said in the 560 it always seems to be the drivers side 
camshaft that does this although in other cases he has seen it seemed to 
break farther forward. This is the first time on any car I have ever heard 
of a camshaft snapping. At this moment I do not like this German Masterpiece 
as well as I did.
John
----- Original Message ----- 
From: "Shayegan, Richard" <rishayegan at davidson.edu>
To: "Mercedes Coupes Mailing Lists" <mbcoupes at mbcoupes.com>
Sent: Thursday, October 27, 2005 8:36 PM
Subject: RE: [W126 Coupe] Intermittant Rough Idle -Me too - HELP!


Well since it happens when the cold start valve closes I think you need
to richen it, but you say it's not mixture, so maybe the MAF plate is
out of adjustment?

-----Original Message-----
From: mbcoupes-bounces at mbcoupes.com
[mailto:mbcoupes-bounces at mbcoupes.com] On Behalf Of Richard Hogarth
Sent: Thursday, October 27, 2005 9:20 PM
To: 'Dwan'; 'Mercedes Coupes Mailing Lists'
Subject: RE: [W126 Coupe] Intermittant Rough Idle -Me too - HELP!

HELP!
When you figure it out, please let me know.
This has been a persistent problem
on my vdhicle and several others that I know of.
I've tried nearly everything and I'm certain that I'm vacuume leak free.

On my car it occurs once the engine comes up to about 65-80 degress on
the
temp guage.
On my vehicle it is totally temp related.
I've done the inject seals, replaced the temp sensor, ignition module,
coil,
plugs, wires,
swapped injectors, pulled the metal fuel feeder lines and cleaned them
out
with a small wire and
carb cleaner as was previously suggested, changed the O2 sensor,
replaced
the exhaust manifold gasgets,
Checked for catylitic converter back pressure, replaced the fuel filter,
adjusted the mixture a million times,
replaced all of the vacuume hoses, t's, one way vacuume valves, checked
the
IAC valve, brought it to a local
MB "specialist", (no dealer nearby), he is stumped; told me to live with
it.

So please HELP!
-Richard Hogarth






-----Original Message-----
From: mbcoupes-bounces at mbcoupes.com
[mailto:mbcoupes-bounces at mbcoupes.com]
On Behalf Of Dwan
Sent: Thursday, October 27, 2005 2:35 PM
To: Mercedes Coupes Mailing Lists
Subject: Re: [W126 Coupe] Intermittant Rough Idle

Possible vac leak at check valve,also idle control unit black
rectangular
unit on the fire wall on 126's

-----Original Message-----
From: Robert Cavazos <jazzman_390 at yahoo.com>
Sent: Oct 27, 2005 2:54 PM
To: mbcoupes at mbcoupes.com
Subject: [W126 Coupe] Intermittant Rough Idle

I need advice from the diagnostic folks.

My wife's '87 560SL typically has a silky smooth idle, lately however
after
the car has been running for about 30-40 mintes the idle starts getting
rough almost like a one cylinder is missing. It can get pretty bad
shaking
the car considerably. When the engine is revved, it seems the miss goes
away
but returns at idle. It does not appear to be related to engine
temperature
and ambient air temp is about 80.

It also dosesn't appear to be realated to driving conditions as it will
occur with driving around town, and when coming to a stop after freeway
driving.

Background
The fuel injectors were replaced a few thousand miles ago, and I checked
the
plugs last weekend looking for anomolies. They all looked fine. I also
wiped
out the inside of the dist cap and rotor thinking there might be
moisture
inside due to a recent few days of wet weather.

Any ideas what else to look at or try?

Bob Cavazos



__________________________________
Yahoo! FareChase: Search multiple travel sites in one click.
http://farechase.yahoo.com
The MB Coupes Website!
W126 SEC Mailing List
Postings remain property of MB Coupes, L.L.C.


________________________________________
PeoplePC Online
A better way to Internet
http://www.peoplepc.com
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.