How hot does yours run? - Mercedes-Benz Forum
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 18 (permalink) Old 02-27-2018, 04:58 PM Thread Starter
BenzWorld Member
 
masand68's Avatar
 
Date registered: Mar 2012
Vehicle: '72 450SL, 107.044-12-000422
Location: Atlanta, GA
Posts: 173
Mentioned: 0 Post(s)
Quoted: 48 Post(s)
(Thread Starter)
How hot does yours run?

I'm not sure what the unmarked tic indicates-I'm guessing around 212F. Mine held about a needle above the mark on our recent road trip. Cruising at 75-80 mph at 3700-3900 rpm. Does this temp seem normal? The only adverse effect seemed to be a tendency to die when idling down (vapor lock?)

4.5 liter d-jet.

How hot does yours run?-img_0501.jpg


Sent from my iPhone using Tapatalk

1972 350SL - 107.044.12.000422
117.982.12.000366
Georgia - USA
masand68 is offline  
Sponsored Links
Advertisement
 
post #2 of 18 (permalink) Old 02-27-2018, 05:14 PM
BenzWorld Elite
 
okyoureabeast's Avatar
 
Date registered: Mar 2017
Vehicle: 1984 380SL
Location: North America
Posts: 1,900
Mentioned: 6 Post(s)
Quoted: 638 Post(s)
I'm assuming each number corresponds to a centigrade value.

175 F equals 80 C.

So that unmarked tic should be about 100 C.

My 380SL's m116 engine heats up to a staunch 90* C. Directly halfway between the unmarked tick on yours and 175.
okyoureabeast is online now  
post #3 of 18 (permalink) Old 02-27-2018, 05:26 PM
Outstanding Contributor
 
MBGraham's Avatar
 
Date registered: Oct 2006
Vehicle: '72 350SL, '85 300D, '98 E320, '19 Subaru Outback (sold '14 GLK250)
Location: Ont, Canada
Posts: 9,585
Mentioned: 2 Post(s)
Quoted: 20 Post(s)
Quote:
Originally Posted by masand68 View Post
I'm not sure what the unmarked tic indicates-I'm guessing around 212F. Mine held about a needle above the mark on our recent road trip. Cruising at 75-80 mph at 3700-3900 rpm. Does this temp seem normal? The only adverse effect seemed to be a tendency to die when idling down (vapor lock?)

4.5 liter d-jet.

Sent from my iPhone using Tapatalk
My 72 Djet runs at just slightly over the 175F mark when driving. maybe 185F? If leftv idling for long period, it may creep up.

Your temperature seems high. At one time my car was like that and I ended up having cracked exhaust manifolds

High temperature can be due to cooling system problems, but also due to timing setting. A retarded timing setting will cause engine to run hot. You could try setting timing so that it is about 27deg BTDC at 3000rpm. This will mean that it will be at about 5deg BTDC at idle with vacuum. This is easy to do with a timing light and perhaps you will run a bit cooler.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
1972 350SL 4.5L, E320, 300D, Outback 2.5 - near Kingston, Ontario
MBGraham is offline  
Sponsored Links
Advertisement
 
post #4 of 18 (permalink) Old 02-27-2018, 05:37 PM Thread Starter
BenzWorld Member
 
masand68's Avatar
 
Date registered: Mar 2012
Vehicle: '72 450SL, 107.044-12-000422
Location: Atlanta, GA
Posts: 173
Mentioned: 0 Post(s)
Quoted: 48 Post(s)
(Thread Starter)
Thanks. I did recently set timing to specs (can't remember the numbers but I'll check it).

I also just replaced the aux fan switch which is supposed to come on at 212.

Mind you, this was hours of running on the interstate at high revs. When I got off on the country roads at 55 mph, it ran just above 175.

Ambient air temp was around 80F.


Sent from my iPhone using Tapatalk

1972 350SL - 107.044.12.000422
117.982.12.000366
Georgia - USA
masand68 is offline  
post #5 of 18 (permalink) Old 02-27-2018, 05:39 PM Thread Starter
BenzWorld Member
 
masand68's Avatar
 
Date registered: Mar 2012
Vehicle: '72 450SL, 107.044-12-000422
Location: Atlanta, GA
Posts: 173
Mentioned: 0 Post(s)
Quoted: 48 Post(s)
(Thread Starter)
Also, last year was a new water pump and I had the radiator cooked out an flow-checked while it was out. I haven't done the citrus flush so maybe some build up in the engine passages?


Sent from my iPhone using Tapatalk

1972 350SL - 107.044.12.000422
117.982.12.000366
Georgia - USA
masand68 is offline  
post #6 of 18 (permalink) Old 02-27-2018, 06:39 PM
BenzWorld Elite
 
redghost's Avatar
 
Date registered: Oct 2012
Vehicle: 1972 220 D, 1974 450SL, 1995 E300D 2002 S430, 1976 300D, 1986 SDL, 1982 SD
Location: Seattle
Posts: 2,708
Mentioned: 2 Post(s)
Quoted: 446 Post(s)
Masan68, the temp sound just fine for an 80* day. What other drains on power were happening at the time? AC? That will add a few calories.

If you have owned and cared for the car from new, your plumbing is probably ok. If this car may have seen sub par attention over the past40 years, I would be planning a flush. There could be malign reactions from maybe having green stuff in, and mixing with G-05. I found a huge excess of crud when I put in a fresh water pump and thermostat. Got new hoses, but that may have had no impact on cooling.

The white crusty was so thick, that I had to use air tools and wire wheels to get down to metal. I was scared to think what was in the block. I did the normal drain, tossed in Dawn solution as a flush, moved to a CA solution for about 200 miles, and five water flushes, before filling with Zerex.

This got me a good flowing system, but the vicious fan failed a few years later, and I had to do the flushing again. There was still more goo left in the system that came out of solution, so it can take years to get rid of what took decades to accumulate.

Clay

74 450SL - Froggy
'86 300SDL - Polei
'82 300SD - Allen

Retired cars
'02 s430 - Victor
'76 300D - Voldemort
'95 E300D - Cleo
'72 220D - Gump
'87 300SDL - POS SDL

92 300SE - #1 boys ride
redghost is offline  
post #7 of 18 (permalink) Old 02-27-2018, 07:06 PM
Outstanding Contributor
 
MBGraham's Avatar
 
Date registered: Oct 2006
Vehicle: '72 350SL, '85 300D, '98 E320, '19 Subaru Outback (sold '14 GLK250)
Location: Ont, Canada
Posts: 9,585
Mentioned: 2 Post(s)
Quoted: 20 Post(s)
Quote:
Originally Posted by masand68 View Post
Thanks. I did recently set timing to specs (can't remember the numbers but I'll check it).
Just to be clear - The numbers I suggested are not the MB specs. The NA specs are designed around emission control. A more advanced setting runs cooler and probably better all round. The euro cars are set that way.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
1972 350SL 4.5L, E320, 300D, Outback 2.5 - near Kingston, Ontario
MBGraham is offline  
post #8 of 18 (permalink) Old 02-27-2018, 11:53 PM
BenzWorld Member
 
DonT107's Avatar
 
Date registered: Mar 2016
Vehicle: 1975 450SL
Location: Central CA mountians
Posts: 57
Mentioned: 0 Post(s)
Quoted: 23 Post(s)
Garage
I see similar temps in my car. Around town and short runs at freeway speed the gauge sits at bit above 175 but extended runs at 70+ mph I see the temp rise also. My car has the cats under the hood (although they are hollowed out) so I have always assumed that to be the cause. This seems backwards to me I would think in town traffic, sitting at stop lights and such would make the temp rise but even with ac on it stays just above 175, and the constant higher air flow at higher freeway speeds would keep Zthe temp lower.

I am assuming you took that picture with engine off and that is why the oil pressure is at 0, cause that could be a whole other story.
DonT107 is offline  
post #9 of 18 (permalink) Old 02-28-2018, 12:07 AM
Lifetime Premium Member
 
Date registered: Apr 2006
Vehicle: 1983 380SL, 2000 S430, 1991 420SEL (retired) - RHD
Location: Gold Coast Australia
Posts: 4,924
Mentioned: 5 Post(s)
Quoted: 386 Post(s)
Lifetime Premium Member
My car always ran hot so I changed the thermostat and checked the radiator. It was part blocked so a new core fixed it and the temp problem.
Aussiemerc is offline  
post #10 of 18 (permalink) Old 02-28-2018, 03:44 PM Thread Starter
BenzWorld Member
 
masand68's Avatar
 
Date registered: Mar 2012
Vehicle: '72 450SL, 107.044-12-000422
Location: Atlanta, GA
Posts: 173
Mentioned: 0 Post(s)
Quoted: 48 Post(s)
(Thread Starter)
Quote:
Originally Posted by MBGraham View Post
Just to be clear - The numbers I suggested are not the MB specs. The NA specs are designed around emission control. A more advanced setting runs cooler and probably better all round. The euro cars are set that way.


Thanks for that.
Good info. I'll give it a try.

Need to verify that the new switch is turning on the fan, although I suspect it is. Aux fan turns on at 212 and keeps the temp at just above the tic.

No AC running and yes, pic taken after shutdown with no oil pressure

Is 3800 rpm normal at 75mph? I think the high revs generate more heat, even though it seems like the increased airflow would offset it. Sort of counter intuitive but maybe normal?




Sent from my iPhone using Tapatalk

1972 350SL - 107.044.12.000422
117.982.12.000366
Georgia - USA
masand68 is offline  
Sponsored Links
Advertisement
 
Reply

  Mercedes-Benz Forum > Mercedes-Benz Roadster Forums > R/C107 SL/SLC Class

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 

Title goes here

close
video goes here
description goes here. Read Full Story
For the best viewing experience please update your browser to Google Chrome