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We have warm weather now in UK and I have been using my recharged and rebelted aircon for a couple of days.

My coolant temperature guage now sits at top dead centre, whereas without aircon it sits left of centre (eighth of an inch). Are the two things related?

If they are related, there are volumes of posts on the subject of where the needle should sit but I haven't seen any reference to whether this is with or without aircon.
 

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We have warm weather now in UK and I have been using my recharged and rebelted aircon for a couple of days.

My coolant temperature guage now sits at top dead centre, whereas without aircon it sits left of centre (eighth of an inch). Are the two things related?

If they are related, there are volumes of posts on the subject of where the needle should sit but I haven't seen any reference to whether this is with or without aircon.
I run my AC 99.9% of the time where I live, so I am not sure about our cars, but that behavior is normal for most cars. Less load without AC will result in slightly lower temps.
Regards,
Jerry
 

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Behavior of your car is same as mine.

The aircon condensor sits in front of the coolant radiator. Heat from the former will preheat the air reaching your radiator, hence the slight rise in coolant temp
 

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Jerry

It will be slightly higher as the engine has to work slightly harder when the aircon is on.

Max
 

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Jerry

It will be slightly higher as the engine has to work slightly harder when the aircon is on.

Max
Right. Isn't that what I said?:confused:
Regards,
Jerry
 

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I think we posted at the same time!
 

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That's why some mountain roads have signs saying "Turn off air conditioners to prevent boil over".

It seems that used to be a much bigger problem... uh... 20 years ago. It is pretty rare that you see a car on the side of the road "boiled over" these days.
 

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That's why some mountain roads have signs saying "Turn off air conditioners to prevent boil over".

It seems that used to be a much bigger problem... uh... 20 years ago. It is pretty rare that you see a car on the side of the road "boiled over" these days.
+1

I can confirm. My car, while traveling outside of Las Vegas on a long uphill stretch in 117 degree weather, with the A/C almost freezing me out of the car at 115 MPH, never got the oil temp over one needle's width above the center mark. The water temp was straight up.
 

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We have warm weather now in UK and I have been using my recharged and rebelted aircon for a couple of days.

My coolant temperature guage now sits at top dead centre, whereas without aircon it sits left of centre (eighth of an inch). Are the two things related?

If they are related, there are volumes of posts on the subject of where the needle should sit but I haven't seen any reference to whether this is with or without aircon.
its normal nothing to worry about all bms do it
 

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I think it depends on the ambient temp not that you are using A/C. In the "winter" (loose term here in Texas) my car runs left of straight up on water and oil temp. In summer they both run straight up.

It is also the reason that leads me to believe that the tach lights are tied to the oil temp rather than the conventional wisdom of the coolant temp (the lights are still on when the coolant temp is normal). I can only see this in the winter as the oil and coolant come up to temp about the same time when it is warmer.
 
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