Rav4.2 Corrosion Where Fuel Sensors Wiring Passes Through Floor

[gcams]

Hi Folk,

Just wondering if anybody has encountered this issue?

This is under the rear seats of a Rav4.2 5 Door (Petrol VVTI 1998cc). I have removed the rear section of carpet. Under each seat (if you fold them up) is a rubber grommet where, what I assume to be the fuel gauge sensor wiring, passes through the floor and into the top of the fuel tank. As you can see from the pic, the area around this section has corroded and is all but disintegrating!

It looks like these circular sections of the body are separate (they are silver and unpainted - the bit of green paint you can see on it was my previous attempt to preserve them with some hammerite anti-rust paint) and almost look like they can be removed. In the photo you can see how there is a "tab" protruding from the top-right-hand corner of the metal disc, as if it could be levered up out the bodywork. Here's another pic:

This leads me to the question, are these silver metal sections replaceable?? If they were, it would certainly be the easiest way for me to rectify this issue!!

Any thoughts/ideas/experience most gratefully received!

Cheers,

Graham

[Tech01]

There are two circular metal plates available as spare parts, one for the LH side of the floor area, the other for RH side:

LH: COVER, REAR FLOOR SERVICE HOLE, 58329-42030

RH: COVER, REAR FLOOR SERVICE HOLE, 58325-42030.

Both are around €20 on my listing. Check part number and pricing at your Toyota parts counter.

The plates are not structural, and are simply held in place with black mastic/sealant. When I lifted one of mine a while ago, I found a thick layer of mud underneath it, sitting on top of the fuel tank. Ideal rust-spot if frequently damp (which it isn't here).

If you don't want to purchase the part, you could always replace the plate with a nicely-made flat piece of plastic, decently masticked/silicone-sealed down. All it does is cover the hole, and keep noise and the elements out.

Your photos show some rust around the seat mountings too, in what otherwise looks like a dry floor. Might be worth checking just how much mud might be between tank and floor, and hosing it away.

Chris

[bothwell_buyer]

I think the extent of the corrosion is a bit unusual. As said above, maybe theres a lot of mud etc that needs hosed away to let the metal dry out. Whichever method you choose to sort it, be careful using silicon on bare metal - I did for a bit of corrosion around a windscreen and it just made the rust worse. I was told that silicon is not the right sealant on top of rust.

Taking the tank out is not difficult but takes a bit of time. I removed the tank from number 1 to give it a clean and a good paint. But by doing so I discovered lots of metal fuel pipes which were corroded, including the filler pipe and breather pipe. I had to replace them and I think from memory I got hold of another tank as the top of the tank was pretty rusty. The tank hangs from the bottom of the car and the prop shaft going to the rear needs removed to allow the tank to drop.

Just be careful hosing the tank in case you wash the thing away!!

[gcams]

Many thanks Chris and bothwell_buyer!! Most helpful replies indeed!

That is great news that these covers can be replaced/purchase without the need for any major structural repairs. Looking in through the hole, things don't look too bad underneath, although I guess once I remove the service covers, perhaps it will tell a different story. The covers seem to be made/finished differently to the main body of the car, so perhaps they are more prone to rust than the bodywork itself? It looks like maybe the salt-spray off the Scottish winter roads as perhaps gathered around the grommets and started the corrosion ball rolling.

Anyway, I'll see what replacements will cost from my local Mr. T and take things from there. Thanks again guys for taking the time to reply. It's a huge help!!

[Tech01]

Ian - Yes, you're right about silicone sealant. Usually contains acetic acid to keep it mobile in the tube, so not best used on bare metal.

[gcams]

Chris, do you know if Mr. T sell a "genuine" tube of something suitable/non-corrosive for sealing the replacement service hole covers back in place?

[Big Kev]

Wee suggestioniser......glue in a short piece of Marley plumbing pipe below floor surface to stop the elements getting at that wee electrical connector......? Ye heard it here furst.....patent pendful.

[IanXT4]

You want a specialised bonding compound that is used in the car industry. I have used SIka products they are available fairly cheaply on eBay and via many car body shops. A lot of cars are now glued together rather than welded.

This website gives an overview of the many products available.

http://gbr.sika.com/en/solutions_products/01/01a001/01a001sa02/01a001sa02100/01a001sa02102.html?fromcorp=true

[The Striding Man]

Great idea Kev, found my rear door bumpstops to be in place as Mr T intended and this potential issue with these wee access panels is next on the list for things to be checked out.

I will put your idea into practice if I find anything untoward, and thanks to gcams for the heads up.

[gcams]

Not a shabby idea at all Big Kev! Definitely something worth exploring! Cheers!

Ian, thanks for pointing me in the direction of the Sika products. Never heard of them before, but a quick look at their products certainly makes them look spot on for the intended purpose!! Ideal!

Arthur, glad you found the thread useful.. I often wonder how many folk are in ignorant bliss of this issue? I guess it's not often the carpet is lifted up, so perhaps the problem is more common in salted-road areas than meets the eye, due to the fact they are hidden away from view for the best part? On the other hand, it could just be my unique problem. LOL! :D

[Big Kev]

Will also be carpet lifting to hav a wee peek and report.....as before, cheers for nod on potential problem.

[gcams]

Just for the sake of anybody else perhaps locating this thread in the future, a quick update...

I have now received the new service hole covers from Parts King. The part numbers kindly supplied by Chris (Tech01) were spot on, and the pair of covers cost ~£43 including shipping from John at Lindop Brothers (Parts King):

LH: COVER, REAR FLOOR SERVICE HOLE, 58329-42030

RH: COVER, REAR FLOOR SERVICE HOLE, 58325-42030.

The LH/RH covers are difference sizes and therefore not interchangeable!

Just waiting for the non-hardening adhesive to arrive in the post, and I'll get them fitted up.

Thanks again everybody who has contributed to the thread!!!

[Parts-King]

Will also be carpet lifting to hav a wee peek and report.....as before, cheers for nod on potential problem.

Mind you don't put your back out lifting carpets......at your age

[IanXT4]

I had a look at these covers today as I was cleaning out my 2004 4.2.

They seemed to be in mint condition from the inside. I pulled the rubber bungs and there was a tiny amount of suface rust on the edges of the holes. I treated this with some waxol but to be honest I don't think it was necessary.

So maybe you have been unlucky with your corrosion ?

In the past I don't suppose you have dropped any liquids in the boot that have pooled in these locations ?

[gcams]

I had a look at these covers today as I was cleaning out my 2004 4.2.

They seemed to be in mint condition from the inside. I pulled the rubber bungs and there was a tiny amount of suface rust on the edges of the holes. I treated this with some waxol but to be honest I don't think it was necessary.

So maybe you have been unlucky with your corrosion ?

In the past I don't suppose you have dropped any liquids in the boot that have pooled in these locations ?

That's very interesting to hear Ian!!

The rust problem was already evident when I purchased the Rav, second hand in 2009, so I don't know the history before that, but it certainly doesn't look like anything has been spilled on the floor, based on the condition of the carpet.

When I removed the old covers, they were terribly corroded on the underside. It looks like the rust has worked it's way through from the outside, rather than originating from the inside, based on how they look underneath. So I think that perhaps the salted roads up here have been largely responsible for the issue. I recall the vehicle was a company car before I bought it, based up in Aberdeenshire, so perhaps it spent a lot of time driving on winter roads without too much TLC??

I'll try and post some photos of the removed/old service hole covers over the next day or two, just for interest sake. They look pretty woeful!! :-)

[Tech01]

The gap under the service covers and on top of the fuel tank looks like a Grade One Mudtrap - mud and w.h.y. thrown up from the road will just accumulate there. The space on ours has half-a-centimetre of dried mud and caked track-dust on top of the fuel/wiring parts.

As you say, add a bit of winter salt, and the poorly-painted discs (the body is much better painted) will just perish. Might be an idea to give the new covers a coat or three of Hammerite before gumming down.

Chris

[gcams]

Just for anybody that's interested, here's what the underside of the rusted service hole covers look like. Pretty shabby! :)

The gap under the service covers and on top of the fuel tank looks like a Grade One Mudtrap - mud and w.h.y. thrown up from the road will just accumulate there. The space on ours has half-a-centimetre of dried mud and caked track-dust on top of the fuel/wiring parts.

As you say, add a bit of winter salt, and the poorly-painted discs (the body is much better painted) will just perish. Might be an idea to give the new covers a coat or three of Hammerite before gumming down.

Chris

Great idea Chris, and one that had already crossed my, no so normally forward-thinking, mind. :) Before I installed the new covers, I gave them 3 coats of POR15 Rust Prevention paint. If you've never used it, I highly recommend it. It sticks like the proverbial to a blanket and cures to a finish like granite. I'm slowly treating the entire underside of my Rav with it. I'm not sure if I'm winning against the rust yet, but the race is long, and one of endurance. LOL! :D

[Big Kev]

So these two far king ferrous doughnuts were £43.00 "including carriage".........?

Toyota dealers must desist from using Concorde 'planes for delivery, FFS.......

[Parts-King]

So these two far king ferrous doughnuts were £43.00 "including carriage".........?

Toyota dealers must desist from using Concorde 'planes for delivery, FFS.......

Would you like half a dozen of 'em big boy? I have your card details...................:D: :D: :D:

[Davrav]

So these two far king ferrous doughnuts were £43.00 "including carriage".........?

Toyota dealers must desist from using Concorde 'planes for delivery, FFS.......

So how much are ones without the rust