PJayUK
Senior Member
- Joined
- Oct 7, 2008
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At last we seem to be heading towards spring, what a lovely morning it was to drive into scenic Watford! 
Anyway this brings me to a question that it now seems the right time to ask, something that has not been an issue over winter.
My question relates to the operation of the climate control on my S320 (it’s a 2000 W220) and its interaction with the running temperature of the engine.
Basically this is what’s happening.
When the climate control is set around 25 – 30 as I have it when its cold the engine temp seems to stay bang on or around 80-90 degrees. There is some small variation for example if stuck in traffic etc but it rarely moves up above 90ish.
As the weather warms up and I set a lower temp on the climate control the engine temperature rises. When its on a cold setting in summer its not uncommon for my engine to run around the 110 mark.
If I select "economy" mode or turn the climate off all together the engine temp also climbs up towards the 110 degrees mark.
The coolant system was drained, flushed and refilled last year with proper spec MB coolant.the thermostat replaced and the system checked by my indi. The coolant level remains static there are no signs of leakage etc.
This confuses me as in previous cars I have owned the opposite happened. Running the AC seemed to increase the temp and turning it off generally caused the running temp to drop off.
This is going to be a source of great annoyance to me over the next few months so any advice, views or comments would be greatly appreciated!
Anyway this brings me to a question that it now seems the right time to ask, something that has not been an issue over winter.
My question relates to the operation of the climate control on my S320 (it’s a 2000 W220) and its interaction with the running temperature of the engine.
Basically this is what’s happening.
When the climate control is set around 25 – 30 as I have it when its cold the engine temp seems to stay bang on or around 80-90 degrees. There is some small variation for example if stuck in traffic etc but it rarely moves up above 90ish.
As the weather warms up and I set a lower temp on the climate control the engine temperature rises. When its on a cold setting in summer its not uncommon for my engine to run around the 110 mark.
If I select "economy" mode or turn the climate off all together the engine temp also climbs up towards the 110 degrees mark.
The coolant system was drained, flushed and refilled last year with proper spec MB coolant.the thermostat replaced and the system checked by my indi. The coolant level remains static there are no signs of leakage etc.
This confuses me as in previous cars I have owned the opposite happened. Running the AC seemed to increase the temp and turning it off generally caused the running temp to drop off.
This is going to be a source of great annoyance to me over the next few months so any advice, views or comments would be greatly appreciated!
