Heavy condensation/fog Auris 2016 HSD

[MG_88]

Bought a Toyota Auris 2016 model two years ago. Immediately  noticed that with cold weather (below 0 celsius) the windows started fogging up on the inside, with temperatures
below minus 10-15 celsius really bad with ice forming on the rear passager windows and constantly having to roll the front side windows up and down to keep the
windshield from fogging upp completely.

Removed all the layers in the trunk and found the carpet to be wet on the left side down against the metal. A minimal amount of water had seeped down in the spare wheel compartment.

Notified the dealership about this and they found it leaked water through the gas lid locking mechanism (they replaced some sort of seal). Fogging up problems countinued and they took the car in again and found the seal to be broken again and once again replaced it. This was two months ago. Fogging problems continue.

Checked the trunk this weekend and is wet in the same spot, they said they dried it up as best as they could but i dont know. Maybe they left it a bit wet and the moist condensates against the cold metal in the trunk?

Ive placed a heater blowing hot air against the area now to see if it comes back again after that.

Anyone else had water leaking from the same spot? I have been reading on the forum about leaks from the rear lights but not from the gas lid locking mechanism.

Another thing i have thought about is that on hot summer days when you start the car the air coming from the vents smell damp at first, could there be something with this causing this amount of condensation? Never seen any AC-run off from the car, but the carpet on the passenger side is not wet.

[TonyHSD]

Hi, 

very likely water ingress . Typically this happens through the rear lights clusters on most Toyota cars. These needs to be checked too. 
You need to find from where the water gets in and fix it properly, anything else it’s not a solution. 
Good luck 

[solero]

The front windscreen damp issue sounds like your air circulation mode could be stuck in internal recycle mode, rather than pulling in external fresh air. Are you having to switch the a/c on to demist the windscreen? If so, the damp air is collecting in your ac evaporator.

[Bper]

Hi MG, You say the dealership replaced the seal around the gas lid locking mechanism twice and you dried the area with a heater but the water leak still persists.After replacing the seal the car windows still fog up excessively, even after the dealership supposedly dried the carpet.

The Damp smell from vents during hot weather. As you suspected, the dealership might not have dried the carpet thoroughly, leading to residual moisture causing condensation and fogging.There could be an issue with the seal installation or the quality of the replacement seal.
While the gas lid mechanism is confirmed, other areas like the rear lights mentioned in your post or the air conditioning system might also be contributing to the moisture problem.
I would take the car back to the dealer and explain the persisting water leak and fogging issues. Ask them to re-inspect the gas lid mechanism seal and ensure proper drying of the affected area. Also discuss with them the  possibility of leaks from other locations, like the rear lights, and request that they give the area a thorough inspection.
If the dealership doesn't find any other leaks, consider getting the air conditioning system checked for potential issues causing the damp smell. Hope this helps😄

[MG_88]

Thanks for the replies! As i wrote i placed a heater against the area for some hours and now it seems dry, i will check the area again after the next rainfall or hose the car down with water.

17 hours ago, solero said:

The front windscreen damp issue sounds like your air circulation mode could be stuck in internal recycle mode, rather than pulling in external fresh air. Are you having to switch the a/c on to demist the windscreen? If so, the damp air is collecting in your ac evaporator.

Thought about that myself, is there some way i can check if its stuck in recirculation? To be clear its mainly the top half of the windshield fogging up, the area where it gets the most air blowing is reasonably clear.

Yep, have to use the AC. If the AC is turned of even during early summer mornings with around plus 10 celsius there is going to be a fine coating of fog on the rear passenger windows.

[solero]

A simple test is to remove cabin filter. Put blower on full speed and insert hand in filter slot horizontallly. Switch between recirculate/external. You should feel a change in draught when switching air mode.

Needing to put a/c on all the time does sound ominous. 

[MG_88]

Just drove the car through a car wash and removed all the layers in the trunk afterwards. The leak from the gas lid seems to have stopped. But noticed there is water pooling around the Battery on the right side of the trunk! Guessing the rear light cluster is leaking too. Cant believe they missed this at the dealership.