Temperature Rising

[pferg]

Last night I took my 1966 230SL out for a workout.  As long as I was moving the temperature stayed just above 180*+.  When I had to wait in line to get gas it started to move up to the red mark.  The thermostat was just changed and new coolant added.  Until yesterday I've not had a problem with the car wanting to run hot.  What do you think could be the problem?

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[rwmastel]

Did opening the heater help?
What temp is the new thermostat?
What antifreeze/coolant did you use?

Only thing I can think of is air in the system.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[Kenneth Gear]

Search the site for plenty of opinions about overheating.  It is a common issue with these cars especially later 280sl's like mine.


A few things to consider....Theromstat, timing could be off, water pump, viscous fan clutch or it may be time for radiator recoring.

Ken G
1971 280 SL
Silver/red

[Cees Klumper]

Assuming the cooling capacity was fine before, maybe there is air locked in the system? 'Burping' it then should help.

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

[pferg]

No I didn't turn the heater on.  The thermostst is for the highest rated temp.  I don't know the brand name of the coolant that he put in the car but when it was not over heating Prestone was what I used.

quote:

quote:Originally posted by rwmastel

Did opening the heater help?
What temp is the new thermostat?
What antifreeze/coolant did you use?

Only thing I can think of is air in the system.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[J. Huber]

I can't remember details but once I heard something about the 87 degree thermo being not good for our cars. 79 is better I believe. I have no idea why or how...

James
63 230SL

[rogerh113]

Hi,

I have a '66 and it pretty much always runs cool (so I know it is possible).  I did have a problem with overheating, which a radiator recore resolved.  It is useful to note that TOO much antifreeze actually impedes the cooling capability of the system.  If you put in more than 50% coolant then you may want to partially drain your system and refill with water.  Sometimes there is a penalty for enthusiasm.....

[rwmastel]

Well, from what Phil said, it was fine before the work was done.  I would guess the 79F thermostat would be a better one to use, but the 87F one should not be sending his temp guage to the red mark.

Common mistakes:
Air trapped in system.  Try to burp air out of the system.
Thermostat not installed properly.  Open the thermostat housing and check.

Searh forums for deatils and see the Cooling System of this page:
http://www.sl113.org/articles/cooling/cooling.asp

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420