Hi all.
I disassembled the bottom part of my front guards and what a bunch of sand and small stones I found gathered where the panel would meet once bolted against the body.
I cleaned it out nicely.
I think it gathered there through time as I used my car for 2 years as a daily driver after it was resprayed some time ago.
It only runs now on weekends and when it is dry. No more rain driving causing small amounts of mud and stone to collect there and cause rust.

Now the question. Those two vents that you can see between the bonnet and the front window, can I just remove their grilles and pop the hose in there and wash then out?
These things were never cleaned in their live and I noticed with my spotlight the other day while peeping in there that there is some mud that collected through all the years. This I don't like as I feel it will cause a muddy paste that will cause rust in there, example when I wash the car.

Before using the hose, remove the vents and spray inside with good bug spray. wait 10 minutes and pull out all the leaves and sticks that you can using your hand.

Then on a warm day (you are in summer like australia), get the hose in there. The water box is a very common place for rust. It is diabolical to fix. It will rust through to inside causing wet carpet, and it will rust through to the engine bay, which you commonly see. too. IT is known to weaken the chassis rail causing the front end to completely rip off on a sideways crash into a pole. I don't expect that most us need to worry about that though

Use plenty of soapy water too, and rinse afterwards. Then get a paintbrush or toothbrush and some rust convertor and treat all the seams. Leave it for 60-90 minutes in the shade.

Nissan never planned for these cars to last longer than 10 years, and the waterbox is evidence of that. It's not painted inside along the seams, and constructed in a way to promote killer rust in structural areas.

After the rust neutralising stuff has done its job (read the instructions) move it back out into the Sun and rinse again with water. Leave it to dry. You can finish it off with some odourless fish oil spray on the seams inside the waterbox too if you want.

The Fish oil might make your ventilation smell a little, for a week or two.

With those vents i think they have a small drain hole at either end under the front gaurds. If you have a build up of leaves and mud in there it will not be able to go through that hole. What i have been told to do with this is make a bigger hole using a hole saw in those ends under the front gaurds (you will have to remove gaurds) so you can get in there properly and give them a good clean. Just an idea. Good luck with it.

Thanks for the replies.
I will look into it this weekend. It is quite hot here in South Africa as it is summer.So weather will help with a quick dry.
Will get my spotlight out while the covers are off and have a peek inside these vents then to see if I cannot see rust and stuff that has already formed. Hopefully I am lucky and it will only have minor rust.
Will try and get a brush in there aswell to rinse and brush at the same time to get everything out.
Will also look into that drain hole story to see if it is not clogged.

It drains from the end of the waterbox through the chassis rail and out in behind the gaurd, Im going through cleaning out the waterbox now, not fun at all.

Hi all
I cleaned out the gutterbox and there was some old leaves and quite alot of dust.
Used the vacuum cleaner. Nice and clean now. Just going to flush the rest this weekend when washing the car.
Using my flashlight I looked carefully into the top vents to see how much rust there is.
Luckily it is only surface rust, but my question, how do I protect it now to rust further in the future.
I am unable to get my hand in there to use a brush to paint something on.
Can one buy antirust stuff somewhere in a spraycan?

Good stuff mate! Lucky there is not too much rust, get some rust converter and put it in a spray and wipe bottle, apply it that way.

Thanks man.
I was worried that it had bad rust.
Just need to protect it now.
What is "rust converter". Is it something that uses the rust in some chemical way to create a seal that will prevent future rust?

Sent you a PDF via email for you to read, hopefully it sortof helps.

Says it converts surface rust to an Iron Phosphate Coating.

Thanks mate.

I got it in the mail.
Looks like it is doing what I thought it would. (Use the rust to convert to a protective layer).
I have an idea that if I use a bottle to spray it on into the vents, I will have to throw away the bottle after use.
Do you know how flowable it is?
Is is almost like water?