MOT Failure due to rust?

[sproutdreamer]

our 04 Yaris 1.3 is due its test next week. The previous test showed advisories for rust just about everywhere underside. However the tester was very picky in this as he also listed as an advisory the bottom edge of a rear door that had a few rust bubbles in the paint. That definatelt should not have been an advisory. I have worked away with a finger sander and chipping tool on the rear halfunderside of the car and after cleaning it up have mostly done it with Hammerite and then Bitumin Underseal. Lots of superficial rust but no holes so the back half should be ok, No time to do the front but visually the back was much worse than the was worse than the front.

So my question is who has had a Yaris fail the MOT through rust in the structural bits and where abouts on the car was it. Also was it possible to repair it?.

[monkeydave]

he sounds a right pain, i have some surface rust already on my front lower control arms and at the bottom of my front struts and that is on a 66 plate, not the best quality

bottom edge of the door is not structural and shouldnt even be put as advisory

[sproutdreamer]

Yes he was a pain and I was quite annoyed at him listing separately about 8 areas of rust. I showed the test place when I had my Avensis done the rust on the Yaris door bottom and they confirmed that not only was the door not an advisory but the car did not even need a door for the test!

[sproutdreamer]

I am most impressed that there are no rust MOT failures. Perhaps the fact of being in an owners club means that car problems are identified and rectified at an early stageor that underbody protection, phosphate coating etc was much improved from a certain date. Maybe around 2000? Certainly you do not see cars around with obvious rusty bodywork which you used to see in the 90's.

[Stevie J]

I had my old Yaris, a 1999 1.0 CDX fail the MOT more than once, on severe corrosion, and it needed extensive welding doing to remedy the situations. It first needed welding at 14 years old, and at that time had only covered about 60K miles.

The areas failed first were the rear outer sills, where the nearside had rust that went through the sill under the back door, towards the back of the sill, near the wheel arch.

The follwoing year the inner wheel arches rotted through, just above the join to the rear sills on both sides of the car, and these needed extensive cutting out of the rotten through areas and welding of new metal.

I had a failure for the petrol filler pipe rotting through and allowing fumes to escape and water to get into the fuel tank, as the filler neck on the Mk1 is metal and unshielded, and they rot through towards the top, so that had to be replaced as well.

Most of the advisories for rust on that car were all involving the rear section of the underside, - sills, inner wheel arches, suspension mounting prescribed areas, and they can, and will, rot through.

My 13 year old 06 plate current Yaris has never failed for rust - yet, but is due its next MOT in 2 weeks.

[sproutdreamer]

Thanks for that ifo Stevie J. I will look more closely at the areas you have cited. I have to get it through the test as wifey loves her car; having said it does not seem a car for a long run (too much road noise over 55mph) it is a brilliant town car as it will fit parking spots unavailable in an Avensis

My Yaris is much worse at the back end than the front but so far I have cleaned up both sub frame suspension mounting areas at the rear, the the trailing arms and the rear cross beam as well as the underside completely  as far forwards as under the rear seats. The sill areas have superfiacial bubbling of paint but seem sound. The only actual rot is a corroded bracket securing the handbrake cable which was easily re-made from strip seal. So far used about a litre of Hammerite and the same of bitumin based underseal. I am impressed with the spray can bitumin  underseal for the hard to get to bits.

I hope I do not need any welding as not many garages seem to do that now around here.

[Madasafish]

I treated ours long ago to prevent rust as the above listed causes - especially the filler pipe - seemed obvious (I wrote much of the  Honest John guide to what goes wrong). I use Dinitrol. The rear sills at join in wheelarch need redoing...regularly due to stone and water damage.

[m456an]

Once a year I give it a little autosol using a metal brush, just takes a minute or 2.

[sproutdreamer]

Yes when I have finished hammerite and underseal I am going to Waxoyl inside the sills and box sections - lots of rubber grommits along under the sills which is what I assume is what they are for? Hopefully this will stabalize as it is for a few years. A lot of work on such an old car but having started I might as well finish it!

[sproutdreamer]

Result - passed MOT with only advisories as slight rust on front floors and sills-so just about to underseal those areas as well as box sections at the front. I was planning to Waxoyl inside the sill and chassis box sections. Is this the best stuff for squirting in and controlling the rust levels as it is at present? One other thought is that I will be wasting my time as the box sections and sill will be rusty and cruddy inside? I have no idea what if anything the box sections are treated with internally-any ideas. The car underside is only undersealed from new in a few specific areas which surprises me.

Strangely an advisory was given as a rear wheel bearing with slight play- except that I have just replaced that one with a new hub/bearing and ABS unit. I wonder if he input the wrong wheel?

[Madasafish]

In my experience - and born out by scientific tests - Dintrol far surpassess Waxoyl  Wax is easily washed away and requires to be diluted with thinners when spraying inside box sections or it may not penetrate rust but sit on top of it. Dinitrol makes specific treatments for external and internal use. The bottom sections of the Yaris were galvanised when new iirc but welding will destroy that at weld points.. The entire floorpan is galvanised..  hence the lack of underseal. But galvanising wears away with time if exposed to water and air- expect a 10 year life of exposed new metal..if galvanised.I don't think the box sections were wax injected from new...

[sproutdreamer]

Thanks Madas...I will go for Dinitrol. Reference my previous post about a new rear bearing having an MOT advisory for some play. I was sure they mustt have input the wrong side into the printed cert but no when I jacked it up there is play-very dissapointing for a new housing/bearing/ABS unit!

[sproutdreamer]

There seem to be a number of Dinitrol sprays for box sections-4941,3125,1000 and 3654 and ML. The ML seems to be the penetrating one. Is ML the best one to use?

[Madasafish]

As the most likely bit to rust are the welds, I would use a penetrating spray.