How long should the windscreen take to demist?

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Mazda CX-5 Sport Nav+ 2.2D AWD
I too have suffered long de-misting times on icy UK mornings. My new CX-5 Nav+ Sport 2.2D can take 10/15 minutes to clear the windscreen inside. I was advised by colleagues at work that some cars shutdown the air-con when temperatures are low. I don*t know if that is true in this case?

What is more annoying is that the screen starts of clear, then 5 minutes after I drive away I have to pull over as I can no longer see. Then there is a long wait for the screen to clear.

I*ve never had a car that behaves like this...
 

ColoradoDriver

Gen-1 Kodo Design
Contributor
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Denver, CO
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2014 CX-5 Touring
You all lost me. Anytime my windshield fogs up when it's cold outside, I have to put the dial to the windshield one, and use heat.

Works everytime and stays clear...if I keep that setting running.
 
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2018 Mazda CX-5 GT
This is my first winter with my 2018 GT. It is the worst vehicle as far as demisting goes. With the blower on a medium setting it only clears a very small section in the middle dash area, and on high it takes the engine forever to warm up. I live in Canada and with -18C this morning I finally scrapped the inside of the windshield after about 10 minutes of idling. I even tried the Meguiar's Anti-fog. spray and that did absolutely nothing.
 

Grendel65

Banned
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2018 Mazda
I haven't tried this, but you can try cleaning the inside of the windshield with shaving foam. Apparently hockey players do this to their face masks to prevent fogging. (shrug)

HAHA! And us divers "spit" in our face mask to accomplish the same thing.
 
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Mazda CX-5 Sport Nav+ 2.2D AWD
This is my first winter with my 2018 GT. It is the worst vehicle as far as demisting goes. With the blower on a medium setting it only clears a very small section in the middle dash area, and on high it takes the engine forever to warm up. I live in Canada and with -18C this morning I finally scrapped the inside of the windshield after about 10 minutes of idling. I even tried the Meguiar's Anti-fog. spray and that did absolutely nothing.

I get the bit about the Diesel engine taking a while to heat up, so wed be blowing cold air for a while. But why is the air-con not doing a better job? In previous cars, Im sure that did most of the job of clearing the screen while the engine warms up.

BTW: My old Ford Mondeo Diesel had supplemental electric heaters that kicked in until the engine was warm!
 

Grendel65

Banned
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2018 Mazda
There are other ways that one could speed the demisting process. Universal 12volt inexpensive car heaters pointed at the windshield will do the job faster then waiting for the coolant to get warm enough in the system to be active at demisting a windshield.
Just a thought after reading what some of you are saying?

They dont work well for really heating the large interior but will do a good job on the windshield. Can't say as I have used these in years and I only thought of it while I was using my heat gun on some wire wrap just now and reading the forums latest thread responses.
 
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2019 CX-5 GT 184 2.2 twin turbodiesel auto - Sonic Silver
I get the bit about the Diesel engine taking a while to heat up, so we*d be blowing cold air for a while. But why is the air-con not doing a better job? In previous cars, I*m sure that did most of the job of clearing the screen while the engine warms up.

BTW: My old Ford Mondeo Diesel had supplemental electric heaters that kicked in until the engine was warm!

I*ve had 3 CX5 diesels and they all demist a treat.
 
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2018 CX-5 SportNav+ 2.2 diesel Manual MGM
Well. The latest on the (lack of) demisting capability is that Mazda say *this is a normal operation of the vehicle and not something we are able to change.*
Any further issues I have with this will need to be taken up with the Motor Ombudsman

Further emails have said:
*All CX-5s would be the same if they were all tested on the same day, in the same temperature, having being parked for the same length of time and having the same levels of moisture trapped inside the car.

I*m sorry there is no fault, the heater has a coolant control valve now for emissions purposes, which does not allow coolant to flow to the heater at idle. Therefore leaving a car idling to demist a screen will take some time, as the heater will not be getting hot.*

In questioning about this coolant control valve:
*The coolant control valve opens at a coolant temperature of 80c and at any engine speed above idle (we believe this to be 1200rpm and above).*

I then asked about the cold coolant indicator and if this valve can be deactivated open:
*The blue coolant light goes out at 60c. The coolant control valve operation cannot be altered as it would affect the efficiency of the engine and therefore the emissions output to which it was homologated.*

I*ll next try when it*s cold and let the car warm up to 80 then try blipping the engine to +1200rpm & see what happens...
 
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Mazda CX-5 Sport Nav+ 2.2D AWD
Well. The latest on the (lack of) demisting capability is that Mazda say *this is a normal operation of the vehicle and not something we are able to change.*

I*ll next try when it*s cold and let the car warm up to 80 then try blipping the engine to +1200rpm & see what happens...

But in the case of a cold engine, why is the air-conditioning not doing a better job?
 
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2018 CX5
quick side question---have a 2018 grand touring here in the US. Do I have wiper heaters? How can I tell and how do you turn them on?? (I must have missed that feature reading the manual)
 
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2019 CX-5 GT 184 2.2 twin turbodiesel auto - Sonic Silver
quick side question---have a 2018 grand touring here in the US. Do I have wiper heaters? How can I tell and how do you turn them on?? (I must have missed that feature reading the manual)

Have a look. They are clearly visible from the outside under the parked wipers and up the driver side of the windshield.
 

shadonoz

SkyActiv Member
Contributor
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State of Jefferson
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2017 CX-5 GT AWD+
quick side question---have a 2018 grand touring here in the US. Do I have wiper heaters? How can I tell and how do you turn them on?? (I must have missed that feature reading the manual)

They turn on with the heated mirrors when you activate the rear defroster.
 
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Fredericton Canada
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2018 CX-5 GT
Thanks...I looked and nothing, so guess our GT did not come with it.:(

Now that seems odd, as I have a new 2018 CX-5 GT and it has the 9 thin wiper de-icer heating wires in the lower windscreen right under the wipers.

As mentioned in an earlier post I agree that the snow I drag in and melts onto my winter floor mats contributes to the humidity buildup on the inside of the windscreen which will certainly turn to frost if you park your vehicle outdoors in sub-zero weather. Fortunately I park my CX-5 inside a garage at night that is above zero so no frost issue in the morning, BUT, when I go to work I have learned to try and park my vehicle facing the sun, as it seems to help prevent much frost from forming.
 
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2019 CX-5 Signature
Now that seems odd, as I have a new 2018 CX-5 GT and it has the 9 thin wiper de-icer heating wires in the lower windscreen right under the wipers. ...

Probably more of a necessity feature in Canada vs. the US.
 
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2018 CX5
Figured it out...Grand Touring only have it if they got the GT premium package:

Active Driving Display (windshield HUD) with traffic sign recognition; Heated rear seats; Heated steering wheel; Windshield de-icer


So if you have windshield HUD, you got the de-icer...otherwise you don't.
 
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Fredericton Canada
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2018 CX-5 GT
Figured it out...Grand Touring only have it if they got the GT premium package:

Active Driving Display (windshield HUD) with traffic sign recognition; Heated rear seats; Heated steering wheel; Windshield de-icer


So if you have windshield HUD, you got the de-icer...otherwise you don't.

As Sig cx-5 says in the post above maybe Mazda specs vehicles coming up here to Canada differently than those to the US, because my GT doesn't have the windshield Active Driving Display and traffic recognition( these come with the Technology Package up here, which I don't have), but I do have heated rear seats and steering wheel, and wiper de-icers.
 
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2018 CX5
You are right but in the northern US we get a lot of snow too! Too bad Mazda doesn't include it for those of us in snow states!