Help - my windscreen mists up heavily as soon as I get in my car

[mjt]

It's an '02 Astra 1.6. Pretty sure the pollen filter was replaced on its last service, but I'll double-check that. I do have AC but only tend to use it during summer as it impacts performance, but I'll give that a go and see if it does the trick. Think it's probably worth giving my windows a good clean too, maybe that'll help.

You have AC??
Use it!

What exactly happens when you use AC with heat? Never really tried it, does the compressor still come on etc? Wouldn't this just make everything cold?

You get conditioned air which is cold. Unless you turn on the heater, in which case it's hot.

I only really use it in the rain as the windows will fog up quickly.
And when it's hit and stuffy in the car, obviously.
It's noisy though, hence not using it 24/7

 

[Alibaba99]

What exactly happens when you use AC with heat? Never really tried it, does the compressor still come on etc? Wouldn't this just make everything cold?

The aircon and heater are two completely separate systems. Switching the aircon on allows the air passing over it to be cooled and have the moisture removed. The heater matrix then heats this air before it passes into the cabin. This means that you have nice and pleasant warm and dry air coming in. This also helps prevent misting (or clears the screen quickly) when used on cold damp mornings.

 

[Clarkey]

Might be forced to check out my pollen filter and/or evap drain. I have this problem but I run the AC all the time so that counters it. It was very cold the other morning though and the AC cut out then the window suddenly steamed up and I was all like WTF. If this is going to be a regular occurance in the winter than my head will likely explode with rage or something.

 

[Phil W]

It's an '02 Astra 1.6. Pretty sure the pollen filter was replaced on its last service, but I'll double-check that. I do have AC but only tend to use it during summer as it impacts performance, but I'll give that a go and see if it does the trick. Think it's probably worth giving my windows a good clean too, maybe that'll help.

I've just done ours on the Astra.

5x T20 screws to get the glovebox out and then 2x I *think* 6mm headed screws to get the panel off. It's a bit of a swine to get in/out but done in no time at all. Depends on the garage but pollen filter always seems to either not get done, or ticked as done but not actually changed

 

[GeX]

Do you park on a hill? I have to park the Clio on an angle, it leans to one side at around 25 degrees. This means that when it rains, water collects in the door jams / seals and at the side that is lower, it overspills the seal and dribbles into the footwell.

Not much I can do about it other than park elsewhere

 

[wildman_33]

Ive been having this exact same problem over the past couple of weeks, I was using my AC to clear it away quickly although this morning it was below 4 degrees so my aircon does nothing to stop itself from freezing over or something so it took ages to demist which was a tad annoying.

 

[Westyfield2]

Even in my previous car without AC it wasn't this bad. Sounds like it's damp somewhere.

 

[Uriel]

I would go for checking pollen filter, door / window seals, damp carpets, ventiation plenum chamber drains. If you keep any liquid in the boot, check it's sealed properly.

I have a very similar problem with my old Skoda Fabia with horrible mist plus a damp smell. It turned out the pollen filter was stuffed with all kinds of crap and it was causing water to drain into the passenger footwell via the back of the glove compartment. Needed an aircon service / bomb to get rid of the nasty smell too (which was probably due to microbial infestation in the aircon).

 

[valerian]

I once heard it suggested leaky/dodgy heater matrix can be to blame for this too?

plus one
check if the water system is losing coolant

 

[Infidelus]

Had something similar happen to me in my first car (many moons ago). As soon as I got in the car and turned the heater on, the windscreen misted up. Turned out the heater unit was knackered. Had to run the car without the heater on for a week or two before I got a replacement part. Winter and no heaters wasn't much fun

 

[shoes]

If this is going to be a regular occurance in the winter than my head will likely explode with rage or something.

NOW is the time to get a camera installed in your car to capture this moment of gold!

 

[uchuff]

This has already been covered above but as I have a mk4 Astra I thought I'd chime in.

As mentioned the AC should clear it in a few seconds, chuck the heat on too and double check you aren't leaving the air recirculating when you shut the car off (the left hand button with the arrows and MAX written on it i think).

A new pollen filter might be a good shout, cheap too.

 

[Overlag]

turn on your heated screen. clears it up nice.

thats a ford only feature.

 

[ahenners]

thats a ford only feature.

It's a nice one though

 

[mjt]

thats a ford only feature.

MINI has it too.

But I can't see the point really. Most modern cars can clear the screen using the vents.

 

[shauncr91]

MINI has it too.

But I can't see the point really. Most modern cars can clear the screen using the vents.

It's good for clearing up frost

 

[mjt]

It's good for clearing up frost

So is a decent HVAC system

I know where you're coming from but it can't be that good if there are only 2 manufacturers fitting them.
Probably interferes with all sorts though, like HUD.

 

[ins0mn1ac]

Corsa/Astra of that age can leak water through the brake servo seal/BCM box, the seal basically falls apart with age/seal under the windscreen/heater matrix failure. Check the footwells for water, push down on them hard since the noise dampner is like a sponge and it will rot if it's wet.

Best thing for stopping moisture in my windscreen I've found is to fill a sock with dry rice and leave it in the window over night, works wonders

 

[dwarf]

Best thing for stopping moisture in my windscreen I've found is to fill a sock with dry rice and leave it in the window over night, works wonders

I had this problem and a sock full of rice sorted it really straight away. I've just left it in my car permanently. It's reusable too, as you can just leave it on a radiator or in the airing cupboard for a night and all the moisture goes and it's ready to reabsorb lots of water again.

RICE + SOCK = WIN

 

[joesmith]

MINI has it too.

But I can't see the point really. Most modern cars can clear the screen using the vents.

I absolutely love having a heated front windscreen! It's much quicker to use the heated window + blowers than it is just using the blowers. And in winter, when there was a rather thick frost on it that would not budge when I tried wiping it with my hand, I just popped it on for a few minutes then popped the windscreen wipers on and off it all went.

I have no idea why more manufactures don't do this, but I wish they did!