Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help




Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 07-23-2013, 11:40 AM
Registered User
 
Join Date: May 2009
Location: Boise, ID
Posts: 149
Coolant Operating Temp?

I was just wondering what the correct coolant operating temp should be. My car usually runs a couple of needle widths below the 175* mark. The only time I have ever seen it actually hit 175* was at wide open throttle up a 6% grade for several miles. Not sure if this is normal, or if my t-stat is stuck open.
__________________
1985 300D 296,000 miles - Project "Rusty" 1/4 mile in 19.9 sec @ 71mph. It's almost rust free and water proof!

2006 Dodge/Cummins 6-Speed - 670HP 1159ft/lbs
Reply With Quote
  #2  
Old 07-23-2013, 11:45 AM
JamesDean's Avatar
Electrical Engineer
 
Join Date: Apr 2005
Location: NE Ohio
Posts: 5,001
80 C is where all of my cars run unless the a/c is on and its hot/humid outside then it will climb up to 100C and go between those two
__________________
Cruise Control not working? Send me PM or email (jamesdean59@gmail.com). I might be able to help out.
Check here for compatibility, diagnostics, and availability!

82 300SD 145k
82 300SD 265k
87 420SEL 230k
89 420SEL 210k
89 560SEL 118k
90 300SE 262k RIP 5/25/2010
90 560SEL 154k
91 300D 2.5 Turbo. 241k
93 190E 3.0 235k
93 300E 195k
Reply With Quote
  #3  
Old 07-23-2013, 11:47 AM
Doktor Bert's Avatar
Das Sturm Uberdoktor
 
Join Date: Jan 2005
Location: Palm Springs, CA.
Posts: 2,667
You are about to stir much controversy in your quest for an answer. Coolant temps evoke more heated responses than religious topics.

However, what you describe is how my 617 runs with a 71C thermostat, which is excellent in my opinion...
__________________
Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership
Reply With Quote
  #4  
Old 07-23-2013, 11:50 AM
Doktor Bert's Avatar
Das Sturm Uberdoktor
 
Join Date: Jan 2005
Location: Palm Springs, CA.
Posts: 2,667
Quote:
Originally Posted by JamesDean View Post
80 C is where all of my cars run unless the a/c is on and its hot/humid outside then it will climb up to 100C and go between those two
Mine will not go over 175F-180F up the 'Grapevine,' WOT (4th gear 75mph) with the A/C on on a 100F day, but I have a custom radiator made from a high-efficiency Modine core with MBZ brass tanks and 25/75 coolant concentration, along with 9 blade fan and 71C thermostat.

100C (212F) isn't a 'bad' temp for a 617 under load, but I don't like to run them that hot...
__________________
Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership
Reply With Quote
  #5  
Old 07-23-2013, 11:51 AM
Doktor Bert's Avatar
Das Sturm Uberdoktor
 
Join Date: Jan 2005
Location: Palm Springs, CA.
Posts: 2,667
One more thing...

The lower hose is exposed to suction. I always install an anti-collapse spring in ALL lower radiator hoses on EVERYTHING I work on...FWIW
__________________
Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership
Reply With Quote
  #6  
Old 07-23-2013, 11:52 AM
Registered User
 
Join Date: Mar 2010
Location: Orillia, Ontario
Posts: 201
I have an 80c thermostat in my 83 240D auto and that is where the temp stays, unless I climb a mountain with the AC on, then it goes up a few degrees, but not much.
__________________
Currently rebuilding engine on 300GD
Reply With Quote
  #7  
Old 07-23-2013, 11:53 AM
JamesDean's Avatar
Electrical Engineer
 
Join Date: Apr 2005
Location: NE Ohio
Posts: 5,001
Quote:
Originally Posted by Doktor Bert View Post
Mine will not go over 175F-180F up the 'Grapevine,' WOT (4th gear 75mph) with the A/C on on a 100F day, but I have a custom radiator made from a high-efficiency Modine core with MBZ brass tanks and 25/75 coolant concentration, along with 9 blade fan and 71C thermostat.

100C (212F) isn't a 'bad' temp for a 617 under load, but I don't like to run them that hot...
Ours 617's rarely go over 90C. Its my 602 that will hit 100C with a/c on. I also have the sound encap panels on too so that likely just helps hold in heat as opposed to the nice big engine bay of the 126.
__________________
Cruise Control not working? Send me PM or email (jamesdean59@gmail.com). I might be able to help out.
Check here for compatibility, diagnostics, and availability!

82 300SD 145k
82 300SD 265k
87 420SEL 230k
89 420SEL 210k
89 560SEL 118k
90 300SE 262k RIP 5/25/2010
90 560SEL 154k
91 300D 2.5 Turbo. 241k
93 190E 3.0 235k
93 300E 195k
Reply With Quote
  #8  
Old 07-23-2013, 12:08 PM
Registered User
 
Join Date: Jul 2004
Location: Barrington, RI
Posts: 5,374
Quote:
Originally Posted by Doktor Bert View Post
You are about to stir much controversy in your quest for an answer. Coolant temps evoke more heated responses than religious topics.
Nice pun.
__________________
06 E320 CDI "Benson", Platinum Blue, 173k mi, DD
91 300D "Otis", Smoke Silver, 127k mi, other DD
98 E300 "Murray", Silver, 125k mi, Stage 2 Rocketchip chip tuned, son's DD

Twelve other MB's owned and sold
2002 Honda Odyssey 237k mi (want to name it "Homer," wife won't let me)
1961 Very Tolerant Wife
Reply With Quote
  #9  
Old 07-23-2013, 02:21 PM
zeke's Avatar
Registered User
 
Join Date: Sep 2007
Location: The Alamo City, TEXAS
Posts: 1,189
My 79 240 D usually runs just above 80*, sometimes, at idle in traffic with AC on in San Antonio during the summer, it will climb to just under 100*

Recently had a water pump fail on the 1980 240D - it had been running hot for a while, and overheated on my wife (got over 120*), so I finally replaced it and the t-stat.

I did not test the t-stat in boiling water (supposed to be an 80* trigger) before installing, but the '80 240D still runs hotter, Just took a road trip to DFW, and it ran at 100* on average. But, the temp would sometimes climb to about 110-115* before the t-stat would open and the temp would drop back down to a bit below 100.
__________________

Current Mercedes
1979 maple yellow 240D 4-speed


Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT
Reply With Quote
  #10  
Old 07-24-2013, 01:39 PM
Registered User
 
Join Date: May 2009
Location: Boise, ID
Posts: 149
Thanks for the help, guys. Are your gauges labeled in metric? Mine is labeled in imperial.
__________________
1985 300D 296,000 miles - Project "Rusty" 1/4 mile in 19.9 sec @ 71mph. It's almost rust free and water proof!

2006 Dodge/Cummins 6-Speed - 670HP 1159ft/lbs
Reply With Quote
  #11  
Old 07-24-2013, 01:40 PM
Doktor Bert's Avatar
Das Sturm Uberdoktor
 
Join Date: Jan 2005
Location: Palm Springs, CA.
Posts: 2,667
I've had both USA and Metric. I also run a Stewart-Warner mechanical for verification.

Your cooling system sounds exceptional. I wouldn't touch it...FWIW
__________________
Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 09:52 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page