Rear window condensation - parcel shelf mod

[Maxz]

Hi all,

I’m starting to tire of the visibility issues caused by the is300’s inclination to hold condensation on the rear screen overnight. From other posts seems like a common complaint solved in transit by constantly running the AC. There are no obvious signs of water ingress around rear doors or boot, so appears to be just general moisture retention. I’d like to minimise the impact first thing, so looking for somewhere suitable to house some silica pouches. Theory is they absorb the moisture whilst vehicle is stationary, then get regenerated by the AC when car is in operation.

Is anyone aware of what is under the plastic grille shown and how to get it off without damaging clips? I’m hoping there is some space to hide the pouches under here to see if they are effective.

thanks!

 

[NemesisUK]

I'm guessing the audio subwoofer is hiding under that grill. You should be able to place the silica gel pretty much anywhere within the cabin to draw away the moisture. I think I'd be double checking for damp carpets etc first

I don't think the a/c will be able to pull the moisture from the silica gel pouches. These need to be regenerated by heating to 110-120c for a couple of hours.

 

[Tam Templeton]

Good luck with the pouches. 

Had many Toyota's/ lexus over the years ...all have been horrendous for rear windscreen moisture . I carry kitchen towel in boot to wipe and have to clear ALL the time in winter ..

[Vlady]

I have the same issue with my GS, also have Pingi car dehumidifier on the back shelf, not sure if it works but still have it behind head restraints. I also always have my air con on to minimise condensation formation and dry the air in the car.

[Brechin Slate]

I have a 1kg bag of silica gel sitting on the parcel shelf.  It sits behind one of the headrests and is invisible from the rear view mirror and from the outside unless you're looking for it.  No condensation issues.  Every now and again I put it in the airing cupboard overnight.

The one I bought (Ganvol) seems to be no longer available but there's a similar one here.  Happy to take pics.

[royoftherovers]

31 minutes ago, Vlady said:

I have the same issue with my GS, also have Pingi car dehumidifier on the back shelf, not sure if it works but still have it behind head restraints. I also always have my air con on to minimise condensation formation and dry the air in the car.

My air-con is always on too Vlad. It is not sensible to turn it off.

[Maxz]

2 hours ago, Brechin Slate said:

I have a 1kg bag of silica gel sitting on the parcel shelf.  It sits behind one of the headrests and is invisible from the rear view mirror and from the outside unless you're looking for it.  No condensation issues.  Every now and again I put it in the airing cupboard overnight.

The one I bought (Ganvol) seems to be no longer available but there's a similar one here.  Happy to take pics.

I like the fact it is black rather than the usual white pouch so more discrete on my dark grey parcel shelf. As Nemesis advises, no point fixing under grille if it takes a decent temperature to regenerate the pouches. Will go for one of these, thanks!

what would be really good is if there was a long thin rectangular version in the same finish as the parcel shelf, could fit in the ridge pointed out and blend in perfectly!

 

[Brechin Slate]

1 hour ago, Maxz said:

what would be really good is if there was a long thin rectangular version in the same finish as the parcel shelf, could fit in the ridge pointed out and blend in perfectly!

 

Pretty sure a decent seamstress (or whatever they're called nowadays) would be able to knock you one up  and fill it with this.  It'd be something like the old draught excluder my granny used to have 🙂. They've even got them on eBay..

 

[Maxz]

Thanks all, just put my order in for two 1kg weight dark/black pouches to try and blend in, will see how effective they are 👍🏻

[Andrew888]

10 hours ago, Maxz said:

Hi all,

I’m starting to tire of the visibility issues caused by the is300’s inclination to hold condensation on the rear screen overnight. From other posts seems like a common complaint solved in transit by constantly running the AC. There are no obvious signs of water ingress around rear doors or boot, so appears to be just general moisture retention. I’d like to minimise the impact first thing, so looking for somewhere suitable to house some silica pouches. Theory is they absorb the moisture whilst vehicle is stationary, then get regenerated by the AC when car is in operation.

Is anyone aware of what is under the plastic grille shown and how to get it off without damaging clips? I’m hoping there is some space to hide the pouches under here to see if they are effective.

thanks!

 

Don't attempt to pry off the grille as they have plastic pegs that are sonic welded. My car literally had one break and wasn't sitting flush and rattles, so I had to repair it by taking it out. That means, side bolsters out, bench seat out, seats down, plastic trims behind the seat out, srs curtain trims out and THEN the shelf lifts out! 

 

[Vlady]

9 hours ago, Maxz said:

Thanks all, just put my order in for two 1kg weight dark/black pouches to try and blend in, will see how effective they are 👍🏻

MAx, keep us posted please on how it performs. The bag you got of amazon is much bigger than the one I have so theoretically should do a good job.

Thanks

[Maxz]

I found a bit of damp inside the boot on the LH side. Seems that the number plate screws go right through the outer boot skin into the interior airspace and so do the corner punch-holes for the boot trim pegs(which are fine toothed so not air/water tight). The lower left boot trim peg was a bit wet, so was the inside of the trim and the plastic boot hinge surround. Given my drive is on an incline probably doesn’t help matters. I’m pained to park the other way (nose) up as had to fix the CCM on my previous vehicle due to water ingress through the pollen/cabin filter housing.

photos below, siliconed the trim clip and number plate holes, plus rubber washers added between the number plate and screw holes for good measure. When the pouches arrive the testing starts...

 

[Brechin Slate]

24 minutes ago, Maxz said:

When the pouches arrive the testing starts...

And of course you have to start with dry carpets and upholstery. Good spot with the fittings degrading the watertight integrity, I'll have a look at mine this weekend 👍

[Maxz]

So siliconing the bottom level of boot lid trim clip holes prior to reinserting the clips + siliconing the ends of the number plate fixing holes appears to have resolved my LH side water ingress problem. Small damp patch on the boot carpet now dry. For good measure I checked the bottom of the Battery compartment well and hybrid Battery compartment, both bone dry. Silicone pouches have arrived and inserted behind the rear headrests, sort of get away with them looking like  small cushions in the back ( well if you use a bit of imagination!).

i went for these in the end, most competitively priced and recognise the brand from other products I have used in the past:

Prem-i-air Eco-friendly... https://www.amazon.co.uk/dp/B01EJLTOKW?ref=ppx_pop_mob_ap_share

Will update on how effective they are and post a pic to show how they look in due course. If anyone else who is having rear condensation issues despite running AC and no known window seal/bonding problems spots the same leak as mine or a new one, please share 👍🏻 Always looking to plug any holes before there are rust or electrical issues setting in.

[matt8]

With all this cold and ice, are any car seals compromised?

A little water gets under a seal, freezing causes expansion, and suddenly there's a gap for water to get in?

[royoftherovers]

I too bought two similar Max, but more expensive versions.

[royoftherovers]

2 minutes ago, matt8 said:

With all this cold and ice, are any car seals compromised?

A little water gets under a seal, freezing causes expansion, and suddenly there's a gap for water to get in?

Heating/warming causes contraction and seal is restored ?

[Maxz]

2 hours ago, matt8 said:

With all this cold and ice, are any car seals compromised?

A little water gets under a seal, freezing causes expansion, and suddenly there's a gap for water to get in?

Seals were ok, no water globules between the body and seals on the interior side. The leak was defo at the lower LH boot trim hole ( or at very least collected at that point where the peg is inserted). Again might not normally be an ingress point for others, given the fact my car is parked on an incline. Just to add I also checked for any weld seam leaks along the lower rear boot threshold (another fault on my previous vehicle that contributed to it’s condensation issues), no problems showing in that respect either.

[Vince Donald]

I've noticed that the rear window takes a long time to clear in the colder winter months.  I had the AC setting where it disables the rear vents, but have found the system runs better in winter if this is set so the rear vents are active.

 

Vince

[Maxz]

So the condensation is gone. It’s been raining heavily for the past two nights and is tipping it down right now. Took the opportunity to squeeze myself into the boot with a torch via the fold down back seats. The LH side boot carpet remains dry but feeling around there is a still a very slight dampness around the edge of the trim where the lowest LH boot trim clip is. Given I just bunged it with silicone and pushed the existing toothed clip back in, probably not 100% watertight. When it’s better weather i’ll replace the clip with a rubber one or get a rubber washer to completely seal the hole. Also pics of the silicone pouches in place, although maybe not really needed now the leak will be fixed!

 

[Vlady]

It's good it is fixed, well done. I hope it won't appear again.

So you reckong silicon pouch is not doing much? I still have it on my Wish list on amazon, waiting for it to drop in price a little but if it doesn't make the difference there is no point in spending money on it.

[royoftherovers]

12 minutes ago, Vlady said:

It's good it is fixed, well done. I hope it won't appear again.

So you reckong silicon pouch is not doing much? I still have it on my Wish list on Amazon, waiting for it to drop in price a little but if it doesn't make the difference there is no point in spending money on it.

I just bought 2 Vlad from amazon for £20. I put one on the dashboard of the Merc and one on the Yaris. Now all condensation has gone. Brilliant.

[Brechin Slate]

14 minutes ago, Vlady said:

So you reckong silicon pouch is not doing much?

If you don't have condensation/damp issues then don't bother with the dessicant bags.  however if you get into your car with wet boots/shoes, transport a damp dog etc then definitely worth the £12-£18 investment IMHO

[Brechin Slate]

1 hour ago, Maxz said:

Took the opportunity to squeeze myself into the boot with a torch via the fold down back seats

Why this method of entry?  Does your boot not open or is potholing a hobby? 🙂 

[Vlady]

12 minutes ago, royoftherovers said:

I just bought 2 Vlad from Amazon for £20. I put one on the dashboard of the Merc and one on the Yaris. Now all condensation has gone. Brilliant.

Hi John, did you buy it in 1ke size? I have one desiccant which is a bit small I would say and I have been using it for the last 4 years if not more, so probably good time to change. The one I have is reusable, I can dry it in microwave and put it back in the car, because it sounds above like I used 1 bag for 4 years non-stop! 🙂

10 minutes ago, Brechin Slate said:

If you don't have condensation/damp issues then don't bother with the dessicant bags.  however if you get into your car with wet boots/shoes, transport a damp dog etc then definitely worth the £12-£18 investment IMHO

Hi Mike, mostly it is a rear window that has condensation on so I think I need one, it won't heart to have one anyway, I guess.