Boot tool compartment leak- found source, how to mend?

[JIQ]

So a month or so ago, I discovered that my carpets were wet (very wet, as in, with a slight amount of pressure, a puddle of water forms). Long story short, after trying to figure out where the water could be coming from, I found that I was able to remove the little rear 'boot tray', look in to the tool compartment (where the car jack is etc.) and saw that there was a pool of water (you could genuinely have a swim in the amount of water that was in there).

Today, I tried the hose trick (spray car to figure out where the leak is coming in) and found that, where the rubber strips are on the roof, rain is running down and making it's way into a gap behind my rear lights. My Dad has taken on the mission to try and resolve the issue before we take it to the garage and spend a whole lot of £'s (cheers Dad!). If you haven't already figured out, I'm not a car person and have no idea what I'm talking about (haha), my Dad, on the other hand, is usually pretty good with fixing cars- we are, however, looking for a little guidance...

If anyone has had this issue before (and I'm sure there will be a few, as it seems like a design flaw), how did you resolve the problem? My Dad thinks he needs to take out the rear light at some point, so any instructions on how to do this, would be great! Also, instructions on how to remove the rear seats (this seems to be pretty simple, but just incase), and lastly, to those who have dealt with a leak... how am I going to dry my carpets?! The smell isn't great, and they look like a pain in the backside to remove...

If you have any questions, feel free to ask...
Thanks! 🙂

[DerekHa]

Hi JIQ,

I've never owned nor worked on the IQ but have done with the MK 1 Aygo and it's two sisters. The Aygo is well known for springing leaks into the boot/spare wheel well. Having had a brief look at an image of the back of the IQ's rear light fittings, on eBay, like the Aygo they have a rubber/neoprene gasket which should seal the back of the rear lights to the body work. This rubber compresses over time, dirt collects in there too and eventually the seal begins to leak. Most people cure the leak by removing the light unit, cleaning the rubber seal and also the bodywork and use a silicone sealer apllied around the area where the two mate and replacing the securing nuts from inside the rear of the car boot. Looks like the rear lights are held in with 3 small threaded studs that will have a nut or similar to fix the light in place from inside the car

As for the carpets and any sound deadening you're best taking them out, letting them drain off first and then taking them indoors for a few days to let them dry out thoroughly before refitting. I expect tackling the wet carpet will be the worst  of the jobs as you'll need to remove the seats and various pieces of the lower interior trim etc. That black rubber bung in your picture is there to be removed and drain out any liquid that collects in the boot and will help in getting the free water out of there if you remove it.

As an alternative to ripping all the carpet out, identify where the carpet is sodden, may only be towards the rear, and get old terry towels under the carpet to absorb as much of the water as you can. Remove the water logged towels after a day or so and dry them out and repeat until the towelling no longer absorbs the water. Eventually the carpet will dry out this way, natural will see to that especially if the weather gets warmer, I've done this in the past with other vehicles. Best to leave something under the carpetted area after you finished with the towels so air can get in there and circulate and speed up drying out.

Hope you get it sorted.

[flash22]

simple answer is to replace both rear light seals they are not cheap tho

81554-74010 (Left and right are the same part No.)

eg.

Price is for the pair

https://toyotadirectparts.co.uk/parts/uncategorised/toyota-iq-2008-2014-rear-combination-lamp-gasket-both-sides/

[Jikky]

Hi had the same problem a few years back,the water comes down from the top roof corners down the back of the lights idown to the boot as the sealant cracks,hope this helps

[APS]

On 3/21/2023 at 10:48 AM, flash22 said:

simple answer is to replace both rear light seals they are not cheap tho

That's not bad at all for two. I just paid over £50 for Yaris equivalents to fix the same issue on that.

[glimp]

I've just bought a 2009 IQ and have the same problem (water in the boot).

Can some kind person please tell me the procedure for removing the interior trim, so I can access the rear light cluster retaining bolts?

I've already had the rear bumper off, so I know that's easy, but I didn't remove any interior trim, for fear of breaking something.

[Dutchrav]

Pull the inside trim to access the taillight. There are 3 nuts that holds each taillight. See picture.
One (middle one) is a bit hidden. After removing the nuts you can pull the taillight out.

 

 

 

[glimp]

On 9/24/2023 at 8:23 AM, Dutchrav said:

Pull the inside trim to access the taillight. There are 3 nuts that holds each taillight. See picture.
One (middle one) is a bit hidden. After removing the nuts you can pull the taillight out.

 

 

 

Thanks for that. I'd seen 2 bolts, but didn't realise there was a third one. I'm getting the windows tinted tomorrow, so I'll ask the guy to remove the first bit of boot trim for me, and I'll take it from there - these people know what they're doing!

[Bernard Foy]

Having the windows tinted, you may have to inform your insurance company.

[glimp]

On 9/26/2023 at 8:14 PM, Bernard Foy said:

Having the windows tinted, you may have to inform your insurance company.

This is true!

[glimp]

Well, I've managed to renew the foam gasket on the back of one of the rear light clusters. Waiting for rain now, to see if the leak is cured.

The interior trim came off with no breakages. The rear bumper was/is a cinch to remove (having done it once, I can now do it in a couple of minutes).

I think I read somewhere that you need to remove the rear seats? Well you don't.

Of the 3 nuts that hold the light cluster in place, the middle one is by far the most difficult to access - a right royal pain in the a**se.

The foam gasket was old and it looked like water might have been getting through at the top (circled in green). Sorry the photo is so poor - I didn't check, and it's all reassembled now.

I also smeared some clear mastic around a rubber grommit, just above the light cluster hole, just in case...

Hopefully it will rain overnight, so I can see if I have a pond in the boot tomorrow.

Fingers crossed.

[Bper]

Spray some water over the area if it doesn't rain just to make sure.👍

[glimp]

4 hours ago, Bper said:

Spray some water over the area if it doesn't rain just to make sure.👍

It stands to reason that more and more IQ's will develop this leaking issue as they get older - and many owners will be completely oblivious to it, as it's not normal to remove both the stowage tray and the blown foam toolkit tray. You can't see the puddle of water otherwise.  I only did it because I wanted to fully inspect my new car.

How many IQ owners are driving around with a pond sloshing around in their boots and they don't even know about it lol!

The good thing is that the boot area seems to be well protected against rust and the carpet is pretty bullet-proof, so no damage has been done.

[74hct04]

I've been waffling on about it elsewhere 😉 on this forum but I am increasingly suspicions that cracked/torn seam sealer in the "gutter" area of the roof seam is a more common contributor to this (and sometimes damp footwells - althought that's usually the short A/C drain pipe that most of us have) than people realise!

I've now got to repair hairline cracks starting in both sides of my gutters' seam sealer, and running down the back of the boot panel seams, as I believe this is why I am getting a (slightly) wet boot.

Maybe it's not normal, but after owning two C1's, I was instantly suspicious of what could be lurking under that foam tray, even before I'd read this forum for the first time! 🙃. A few days of heavy rain last week and yup, there's a leak!

Edit: Thanks for Jikky for documenting this here:

 

[glimp]

3 hours ago, 74hct04 said:

I've been waffling on about it elsewhere 😉 on this forum but I am increasingly suspicions that cracked/torn seam sealer in the "gutter" area of the roof seam is a more common contributor to this (and sometimes damp footwells - althought that's usually the short A/C drain pipe that most of us have) than people realise!

I've now got to repair hairline cracks starting in both sides of my gutters' seam sealer, and running down the back of the boot panel seams, as I believe this is why I am getting a (slightly) wet boot.

Maybe it's not normal, but after owning two C1's, I was instantly suspicious of what could be lurking under that foam tray, even before I'd read this forum for the first time! 🙃. A few days of heavy rain last week and yup, there's a leak!

Edit: Thanks for Jikky for documenting this here:

 

Can you pinpoint exactly where you think the leak is, please? I've done the gasket around the left-hand light cluster and it was a fail - still getting water in the boot.

I'm not sure where you're describing.

[74hct04]

Sorry, I think I was perhaps being a little too negative/dramatic as I can't be sure it's actually that widespread an issue. (What I have noticed is that I am not the only person to have tears and cracks in the seam sealer of various panels, however). Nethertheless, I'd suggest having a look anyway.

In the attached photo I've added red lines over the seams that have have the hairline cracks in the sealant on my car. On the right-hand side, I've tried to highlight the bottom of the 'gutter' with the end of it's black rubber/plastic trim or finisher just about visible above . If you look at Jikky's photo it shows the view looking down from above onto the roof with the black rubber/plastic removed, revealing the clip for the trim and seam-sealer underneath. Indeed for my car, the cracks I've outlined run up through a right-angle into the sealant of the roof, in the same area as Jikky's 'crazing'. How far along mine run is an unknown at this point as I've yet to remove that trim piece but it's easy to flip up the end for an initial assessment. I think the workshop manual suggests refitting is done with the parts warmed to specific temperature ranges and I am reluctant to remove the trim until I am prepared to finish the job.

The photo is not of my actual car as it's a bit late and dark for that right now, but from the modest detail of this low-resolution photo, I think this car probably doesn't have the issue mine does.

 

Edit: If you're getting small quantities of water into the boot (mine is probably a couple of teaspoons worth after a day of stormy downpours) you could have the cracks I think are causing mine, otherwise please double-check this forum but I believe the foam  seals around the vents (of which you can see one in your first photo) can also leak after a while. Perhaps tape some bits of tissue around the boot or even dust some talcum powder around if you need to identify the path(s) the water is taking.

[FROSTYBALLS]

Could try Captain Tolley's Creeping Crack Cure -

https://captaintolley.com/

A while ago a member used this on their Avensis roof seams successfully. Available on Amazon, etc.

[74hct04]

Thank you Frostyballs. I keep seeing it mentioned so I think I will have a go!

I'd been planning another 'adventure' with my tube of Kent Quickseal, but it's a viscous messy stuff that'd probably end in the ugly application of more expensive colour-matched white paint, so I'd rather avoid it.

[Cyker]

16 hours ago, FROSTYBALLS said:

Could try Captain Tolley's Creeping Crack Cure -

https://captaintolley.com/

A while ago a member used this on their Avensis roof seams successfully. Available on Amazon, etc.

I just love the name of that stuff!  

It does sound slightly like a constipation remedy tho'  

[Jikky]

17 hours ago, glimp said:

Can you pinpoint exactly where you think the leak is, please? I've done the gasket around the left-hand light cluster and it was a fail - still getting water in the boot.

I'm not sure where you're describing.

[glimp]

15 minutes ago, Jikky said:

Thanks Jikky. Sorry, but I have no idea where that is (I'm thick).

[Jikky]

2 hours ago, glimp said:

Thanks Jikky. Sorry, but I have no idea where that is (I'm thick).

Its the channel under the plastic roof trim drip rail (at the rear of the car ,with the trim removed)I gave the trim a pull towards the back of the car and it slid out.Hope this helps.

[glimp]

3 hours ago, Jikky said:

Its the channel under the plastic roof trim drip rail (at the rear of the car ,with the trim removed)I gave the trim a pull towards the back of the car and it slid out.Hope this helps.

Thank you my friend. I appreciate you taking the time to explain.