Main windscreen mists up

[CaptainCoddy]

Sorry if this has been talked about before but unless i have the air con on in my Xsara Picasso the windscreen mists up! anyone know what could be causing this?

[oneday]

possible leaking heater matrix or blocked drain for aircon. had this on my xsara turned out to be leaking heater matrix used hardly any water fixed by adding k seal

[Mandrake]

Or the inside of the windscreen needs cleaning. A spotlessly clean window won't mist nearly as easily as a dirty one. Once it starts misting and you start wiping it with your hand, sleeve, or a dirty cloth to try and clear it it tends to just get dirtier and the problem gets worse. Give it a really thorough clean with something that will leave no left over residue and see if that helps.

[oneday]

just an after thought you have got the ait recirculation swithed off when aircon is off

[CaptainCoddy]

just an after thought you have got the ait recirculation swithed off when aircon is off

Yes mate, i have got the recirculation switched off.

[oneday]

id go with mandrake first and make sure the windscreen is spotless first.

[CaptainCoddy]

Or the inside of the windscreen needs cleaning. A spotlessly clean window won't mist nearly as easily as a dirty one. Once it starts misting and you start wiping it with your hand, sleeve, or a dirty cloth to try and clear it it tends to just get dirtier and the problem gets worse. Give it a really thorough clean with something that will leave no left over residue and see if that helps.

The screen is clean. Never had this problem with any other car, very strange

[citroenxm]

When the car is hot or warm, turn the heater to cold, then turn to hot.. Do you get a strange "Curry" type of smell??

Heater matrix if so.. But then the misting up also tells this story too.

[oneday]

if the matrix is leaking it will only use a small amount of coolant mine used about half a litre every 2 months but would mist up the windscreen untill the heater was red hot or i switched on the aircon. and the carpets never got wet. might be worth putting some sealant in the coolant just to see if this stops the misting up.

[CaptainCoddy]

When the car is hot or warm, turn the heater to cold, then turn to hot.. Do you get a strange "Curry" type of smell??

Heater matrix if so.. But then the misting up also tells this story too.

I can't say i've noticed any strange smells, but i will try that tomorrow.
If it is the heater matrix, is this expensive to have fixed?

[CaptainCoddy]

if the matrix is leaking it will only use a small amount of coolant mine used about half a litre every 2 months but would mist up the windscreen untill the heater was red hot or i switched on the aircon. and the carpets never got wet. might be worth putting some sealant in the coolant just to see if this stops the misting up.

I will give that a try also oneday! thanks for your help

[oneday]

think its a dash out job i never changed just added k seal and ran like that untill i sold it 2 years later. and many thousands of miles on the clock. never happened again so didn,t worry about it.

[citroenxm]

Not sure, Not done a picasso.. But it could be a dash out job though...

It is on the Xantia, but its NOT on the XM... I have a feeling it is a Dash Out job..

[myglaren]

Mine mists up a lot compared to the estate that I previously had. The screen gets very filmy, inside and out, I think it has been treated with something evil.
It is cleaned regularly with lots of different cleaners and solvents and never seems to stay clean for long.
The coolant has recently been changed, flushed, flushed again with Forte Cooling System Flush, refilled with the correct Citroen antifreeze and Forte Cooling System Sealer (precautionary)

I am thinking along the lines of it wanting a new cabin filter and possibly the aircon drains probing.

[CaptainCoddy]

Thanks for all your help and ideas guys i will try them out and get back on here and let you know the outcome!