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Old 27th July 2019, 19:32   #1
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Default A Conundrum?????

OK all you wise people, Here is a conundrum for you.

After curing a water loss problem I had with my car I now have a puzzling thing happening.

In a 1000 miles, the engine has NOT used any water, But now I have noticed something strange happen I have recently due to the very hot weather have had the A/C on and I have had to top up a small amount of water into the rad,

So to check I did not use the A/C and there was no more water loss. Put the A/C back on and I had to add more water.

I did not think there was a connection between the A/C and the water system ? can anyone clarify what might be happening?
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Old 27th July 2019, 21:49   #2
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Probably nothing to do with the air on being used, but on the other hand,maybe. We have just gone through some very hot weather. The air con has to work harder to get the temperature down to what it is set at. Therefore your engine works harder, so working harder it gets warmer, it may have had slight leakage from the radiator cap. Any residue around the cap area will tell you. During the hot weather, I alternate between full aircon and economy setting.Daft though it may sound,in the hot weather we have just had, when the aircon is on, it makes my clutch heavier to operate.Perfectly ok otherwise.
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Old 27th July 2019, 22:02   #3
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Probably nothing to do with the air on being used, but on the other hand,maybe. We have just gone through some very hot weather. The air con has to work harder to get the temperature down to what it is set at. Therefore your engine works harder, so working harder it gets warmer, it may have had slight leakage from the radiator cap. Any residue around the cap area will tell you. During the hot weather, I alternate between full aircon and economy setting.Daft though it may sound,in the hot weather we have just had, when the aircon is on, it makes my clutch heavier to operate.Perfectly ok otherwise.
I understand what you say, But there is no residue around the cap area,If i dont use the air/con I dont lose water.If I do I have to top the water upI only need to use the A/C for a short time for this to happen.
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Old 27th July 2019, 22:21   #4
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I have the same symptoms but have never found the cause despite changing hoses, rad, head gasket etc. A mystery!
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Old 28th July 2019, 06:08   #5
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I may be a million miles wrong here, I often am, but it crossed my mind that you can often see slight water dribbles from air conditioning units in foreign countries, USA and suchlike, it appears to be usual. I'm assuming all air-con units work on the same principle.

But I could be wrong.
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Old 28th July 2019, 08:19   #6
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I may be a million miles wrong here, I often am, but it crossed my mind that you can often see slight water dribbles from air conditioning units in foreign countries, USA and suchlike, it appears to be usual. I'm assuming all air-con units work on the same principle.

But I could be wrong.

I don't think the water dripping is from the cars coolant, it is from the air con, I think it is condensation.

my first car that had air con, I took it to the garage because of the dripping, so embarrassing

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Old 28th July 2019, 10:07   #7
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I don't think the water dripping is from the cars coolant, it is from the air con, I think it is condensation.
You're spot-on Ian! Water vapour in the air inside the car condenses on the cold evaporator within the air con./heater unit and drains to the road surface as clear water through two specific tubes. It's most noticeable just after the engine has been stopped when quite a pool can form.

As for Number 6's question, I am baffled too.

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Old 28th July 2019, 11:44   #8
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An issue with the Heater Matrix maybe ?



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Old 28th July 2019, 15:22   #9
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An issue with the Heater Matrix maybe ?



Paul.
Heater Matrix has been flushed and system bled some time ago and checked for leaks so I dont think that is the problem
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Old 28th July 2019, 15:52   #10
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This is a long shot.

The additional load placed on the engine when the aircon is drawing power will lead to a larger vacuum in the inlet manifold. Could it be that as a result of this larger vacuum, a small amount of coolant is being sucked in past a marginally sealing IMG?

Last edited by MSS; 28th July 2019 at 16:06..
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