Hans - some of what you're reporting can be a bad/broken vacuum pump. It
might be a good idea to remove it and check it over. It is driven off the
front of the IP, at half the crankshaft speed. It can make a lot of
"knocking" sounds when internally broken!
Werner
----- Original Message -----
From: "Hans Neureiter" <[EMAIL PROTECTED]>
To: "Mercedes Discussion List" <mercedes@okiebenz.com>
Sent: Wednesday, March 14, 2007 7:00 PM
Subject: Re: [MBZ] OM 617 badly sick (was 126 pre chambers)
One other observation: the frequency of the knock is as close as I can
tell 1/2 the rpm i.e. the result of the powersroke of one of the
cylinders.
On 3/14/07, Hans Neureiter <[EMAIL PROTECTED]> wrote:
Today I went to do some more investigating:
Excessive blow-by is not evident. The turbo is slightly oily, but the
shaft is moving a little in radial direction.
The motor started right up. A huge, scary clunk at first that turned
into a steady, loud hammering. Oil pressure first pegged and went to
2.5 bar at a steady 800 RPM idle.
When operating temp reached 85 C (after ~ 5 min.) pressure dropped to
slightly above 1 with a few short excursions to below 1 bar.
Loosening the injector lines resulted in a noticeable reduction of
knock intensity but was equal for each cylinder.
Using a stethoscope, the highest intensity of the knock is apparent
near the front crank seal and at the Vac.pump housing.
Lots of blue smoke at first that never really cleared.
Motor ran for at least 20 minutes until turned off.
Questions:
Can injectors/prechambers be ruled out as major cause?
Does oil pressure behavior indicate crank bearing failure?
Does most noise coming from front crank seal indicate balancer failure?
Do I have a conglomeration of failing parts (Turbo seal = blue smoke,
etc.)
My conclusion so far: 90% bottom end problem. But what?
On 3/14/07, Trampas <[EMAIL PROTECTED]> wrote:
> I have two W126s with OM617s that my wife is after me to get rid of. I
> am
> located in Raleigh NC. Just in case you need an engine.
>
> One of the cars is a 1985 300SD with around 300k miles, runs and drives
> but
> needs front end rebuilt (tie rods etc). Also the body is a bit rough as
> it
> does have 300k miles.
>
> The other one is a 1984 500SEL which I put a OM617 in, the engine runs
> great, but the body is rusted. The engine came from a 1982 300D that
> was in
> worse shape.
>
> I have been meaning to get some pictures of the two beasts, will let
> you
> guys know when I get some up.
>
> Trampas
>
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]
> On Behalf Of Peter Frederick
> Sent: Tuesday, March 13, 2007 9:08 PM
> To: Mercedes Discussion List
> Subject: Re: [MBZ] 126 pre chambers
>
> Worst case it ingested water and it's toast (bent rods), but in that
> case the response would have been pretty fast and probably wouldn't
> have started. Lots of blue smoke out the back before it died?
>
> Don't know -- time to pull the injectors and do a compression test.
>
> Peter
>
>
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--
Hans Neureiter, Houston, TX
'82 300SD, '95 E300D
--
Hans Neureiter, Houston, TX
'82 300SD, '95 E300D
_______________________________________
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