66 230sl overheating

[jrrx]

Hi all,

I have a 66 230sl which starting to overheat only when driving on the freeway. It is fine around town and idling, I have replaced the radiator and thermostat checked the timing and air gas mixture. I am running out of options. Thought about water pump but  don't have anyother  ideas. Thanks Jim

[Richard Madison]

Jim:
Use the forum Search (top of every page) for "overheating"
and see if we have anything in the Technical Manual by doing a search there. Find the Tech Manual on the website home page.

Richard M, NYC

[waqas]

Overheating under load points to incorrect operation of the distributor. Have you checked your vacuum lines?

[ja17]

Hello Jim,

You replaced the radiator with what?  Also Try turning the heater on full blast on your next freeway trip and let us know if this helps.  

Make sure the correct thermostat has been used. The originals are dual acting. As they open one coolant passage another passage is closed.