"Rear inner sill panels corroded" - MOT advisory

[MK21800]

As the title suggests.

I have to admit to not quite knowing what I'm looking at but I crawled under it with a torch and had a good look around. I can't see anything that I recognise as "corrosion".

There was a spot of brown but it turned out to be kind of dusty stuff that I could wipe off with my finger. Aside from that, I'm just looking at underseal as far as I can tell.

The inspector said to me when I was chatting to him about the advisories "No problem, simply scrape the old underseal off with a screwdriver, treat the rust then put some more underseal on. This should stop it in its tracks,". But I didn't have the presence of mind to get him to point out exactly where he thought it was,as I was assuming it would be obvious. Bearing in mind this was just an advisory. I think they were indicating that it's just surface corrosion.

He was also claiming that this is due to the underseal that is put on when the car is produced at the factory "trapping some moisture". Seems weird to only spot this after 31 years....

Are there particular spots I should be looking at? Is it hard to spot?

Also, is there a place you could recommend that might get it on ramps and give me a second opinion? South West of London.

Is it possible that the guy was just kind of making it up to appear more "thorough" in the MOT? I seem to be getting advisories each year that are then not spotted the year after.

I feel slightly concerned about this. Should I be?

How serious is this if it gets worse?

Any comments welcome...sorry about the slightly vague "how long is a piece of string" post but I am not too familiar with this subject. I did have a car once that had to be scrapped due to MOT failure on rotten sill panels, so I find myself a little worried.

It was a couple of months ago that this was pointed out to me.

[GT_II]

The picture below (from post by Godspeedos on vwgolfmk1.org.uk), shows the area they are most likely talking about - around the rear beam mounting bracket. This area is not easy to examine from the ground, even with the car jacked up, particularly if your car has the body kit. A good light and a large mirror might help you check it over, particularly the inner edge of the pinch weld at the right of the picture:

Rear inner sill.jpg

[essextom]

if you've caught it early it should be fine. but id suggest getting someone to strip the area back treat and repaint professionally. no offence to your mot guy but he might not be experienced in this work. best to get this done properly once.

[MK21800]

Thanks for the help. Sorry about the slight delay on getting back to you, I've not been able to get on here for a while.

So the advice is basically to get it done by a pro, maybe describe to them the area we're talking about.

I have a body shop that has been recommended to me by a friend which is apparently not the cheapest but very honest and communicative. Is there a particular price range I should be expecting for this kind of work?

[RussGLAuto]

If it's a relatively small area we're talking about, assuming you may need some welding (?) I would budget £5-700... depending on how much time it takes.