Methinks the thermostat (if it's working right) should provide prompt
warm-up regardless of fuel. The MBZ thermostat is unlike the ordinary US
thermostat in that it has two sealing functions. When cold, it forces all
of the flow back into the engine with a little going to the heater core.
The housing forms the sealing surface so housing corrosion could also be a
problem here. I'd be inclined to take a hard look at the thermostat before
looking elsewhere.
Scott Ritchey
-----Original Message-----
From: mercedes-boun...@okiebenz.com [mailto:mercedes-boun...@okiebenz.com]
On Behalf Of Dillon, Meade M CIV SPAWARSYSCEN-ATLANTIC,53310
Sent: Wednesday, January 06, 2010 12:46
To: Mercedes Discussion List
Subject: Re: [MBZ] running temps in the cold?
Correction to the below, I was mis-remembering. Milli-volt method is
what I was thinking about for adjusting IP timing. Here is a link to
the thread with much better explanations than mine:
http://www.peachparts.com/shopforum/showthread.php?t=152389
21-odd pages of reading, fun if you have the time to sort through it
all.
-Max
-----Original Message-----
From: mercedes-boun...@okiebenz.com
[mailto:mercedes-boun...@okiebenz.com] On Behalf Of Dillon, Meade M CIV
SPAWARSYSCEN-ATLANTIC,53310
Sent: Wednesday, January 06, 2010 12:34 PM
To: Mercedes Discussion List
Subject: Re: [MBZ] running temps in the cold?
Ernest,
I'm not running biodiesel, and I think that my car takes too long to get
up to temp (about 3-4 minutes of driving, ambient temp ~28 deg F).
I suspect there is no problem with your car if others are seeing similar
behavior on biodiesel. Worth checking the oil cooler thermostat but I
don't think you'll find a problem. Also worth looking at the thermostat
housing to see if there is erosion allowing coolant to bypass.
I'm afraid you'll need to engineer a solution given the different fuel.
Here's an idea for adjusting the IP timing to match your fuel. Glow
plugs can be used to measure combustion temperature, in a fashion. They
are made of dissimilar metals and so resistance changes with
temperature. Theoretically, you can measure resistance across a glow
plug and adjust the IP timing to find the peak combustion temperature,
and so set your IP timing for greatest efficiency of your fuel type. I
understand that Caterpillar uses this method for setting the IP timing
for their diesel engines. In this case you'd want to hit the
temperature peak.
In practice, setting IP timing in this manner on an OM617 is rather
difficult. One way would be to mount a long lever to the IP so that you
had the leverage to overcome the spring resistance in the injection
lines, and a helper to mark the position of the IP when you find the
temperature peak. Also, tying all the glow plugs together so you're
measuring average resistance across all the glow plugs will be more
accurate. Of course, you don't want them to be connected to the relay
during these procedures.
There's a long thread on this topic on the peachparts forum, very
tedious reading as the principle poster doesn't believe in paragraphs or
punctuation, but interesting. I haven't played around with the idea
yet, but someday I plan to do so.
-Max
-----Original Message-----
From: mercedes-boun...@okiebenz.com
[mailto:mercedes-boun...@okiebenz.com] On Behalf Of ernest breakfield
Sent: Tuesday, January 05, 2010 4:43 PM
To: Mercedes Discussion List
Subject: Re: [MBZ] running temps in the cold?
hi Max!
i'll check the temps with a laser thermometer again, but haven't
found any real disparities in the past.
good thought about the airflow over the rad when there's no coolant
flow; but there's also the oil cooler, and all the heat lost to air
that's generally circulating around the engine compartment,...
by any chance are you running BioD? i think this is the main
contribution factor in this issue,...
i guess i wasn't clear enough that this seems to be most apparent in
colder weather when running BioDiesel; in more normal temps and/or on
regular #2 it's usually just over 80C where we'd expect it, varying to
occasionally right up around 100C on an extended climb in warmer
weather. this thing really seems happiest (read: more powerful, smoother
shifting) when it's warmer, and i was thinking there might be some
advantage to keeping it closer to its target temperature. (like more
power, better oil flow, better evaporation of crankcase water
contaminants,..).
i strongly suspect it's in a large part because BioD doesn't put out
the same amount of waste heat as #2; many others in the BioD fleet
around here seem to have noticed the same thing. the effect is even more
exaggerated with the W/SVO crowd. seems that the cooling systems in
these things is designed (not surprisingly) to expect the waste heat
resultant from running PetroDiesel, and the cooling system is
overcooling when running anything else.
am still really interested in hearing about the thoughts regarding
shrouding (like yours; good point again!).
cheers!
e
Dillon, Meade M CIV SPAWARSYSCEN-ATLANTIC, 53310 wrote:
Maybe your temperature gauge is not accurate? My car reaches normal
operating temperature after just a couple miles of highway, of course
its an OM603. My normally aspirated OM617 would require about the
same,
maybe a little longer. Does your ALDA need adjustment - maybe fuel is
too lean for the air the turbo is pushing, and more cold air means
lower
combustion and engine temperatures?
I don't think you should need any radiator shroud/cover if your system
is working right - thermostat should be staying closed so no flow via
the radiator that you can affect in order to raise engine
temperatures.
-Max
-----Original Message-----
From: mercedes-boun...@okiebenz.com
[mailto:mercedes-boun...@okiebenz.com] On Behalf Of ernest breakfield
Sent: Tuesday, January 05, 2010 2:26 PM
To: Mercedes Discussion List
Subject: [MBZ] running temps in the cold? (was: Re: glowing in the
cold)
only slightly related; what kind of operating temps are you guys that
live in real cold seeing?
here where temps rarely get much below the 20s-40s this time of
year, i still don't often see the coolant temp indicate anything above
80C until it's been on the highway at speed/load for many miles. (i've
already played with changing out the thermostat to units i've verified
are opening at the proper temps.) i'm sure this is exacerbated by the
fact that we're running almost pure BioDiesel almost all of the time
as
we can see the temps come up quicker and higher when we have to run #2
instead of B99 on road trips, but i can run around town all day and
never see the coolant reach the normal area on the gauge even when
temps
are into the 50s and higher. FWIW, the car starts fine on a single
glow
cycle, but (no surprise!) definitely runs stronger when warm.
i know some veteran diesel-heads used to be seen with radiators
shrouded or grills even completely blocked in the cold to keep temps
up
where they're supposed to be; what are the thoughts regarding doing
this
with a 617 turbo-diesel?
cheers!
e
'85 300D (~187K)
Berkeley, CA
Dillon, Meade M CIV SPAWARSYSCEN-ATLANTIC, 53310 wrote:
OK, thanks for the input guys. I can't justify the $$$ for the
Webasto unit, so I guess I'll just have to put up with the cold for
another month or so.
-Max
-----Original Message-----
From: mercedes-boun...@okiebenz.com
[mailto:mercedes-boun...@okiebenz.com] On Behalf Of Dwight E. Giles,
Jr
Sent: Tuesday, January 05, 2010 12:21 PM
To: 'Mercedes Discussion List'
Subject: Re: [MBZ] glowing in the cold
I only ever tried the block heater once on the 300D 2.5t for that
reason-couldn't see any difference in heat any sooner so I tucked the
cord back onto bumper and have never used again.
Dwight E. Giles, Jr.
1978 240D 4 speed. 218K + miles.
1990 300D 2.5t 170K miles.
Wickford, RI
-----Original Message-----
From: mercedes-boun...@okiebenz.com
[mailto:mercedes-boun...@okiebenz.com]
On Behalf Of Curt Raymond
Sent: Tuesday, January 05, 2010 12:05 PM
To: Diesel List
Subject: Re: [MBZ] glowing in the cold
Max,
I can't really tell the difference in how quickly I get heat, its the
center of town for me pretty much no matter what.
If I lived somewhere seriously cold I'd get a radiator heater to go
along with the block heater, another 1000w into the radiator would
surely give quicker cabin heat...
_______________________________________
http://www.okiebenz.com
For new and used parts go to www.okiebenz.com To search list archives
http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
_______________________________________
http://www.okiebenz.com
For new and used parts go to www.okiebenz.com To search list archives
http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
_______________________________________
http://www.okiebenz.com
For new and used parts go to www.okiebenz.com To search list archives
http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
_______________________________________
http://www.okiebenz.com
For new and used parts go to www.okiebenz.com To search list archives
http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
_______________________________________
http://www.okiebenz.com
For new and used parts go to www.okiebenz.com To search list archives
http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
_______________________________________
http://www.okiebenz.com
For new and used parts go to www.okiebenz.com To search list archives
http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
_______________________________________
http://www.okiebenz.com
For new and used parts go to www.okiebenz.com
To search list archives http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
_______________________________________
http://www.okiebenz.com
For new and used parts go to www.okiebenz.com
To search list archives http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
