Rusty sills

[Kieron G]

I noticed some bubbling under the paint on the rear of n/s sill on our 2001 multispace.
After scraping paint off realised that is corroded through from inside. 
Cut a square out with grinder and found that it all felt thin and rusty. 
Purchased full replacements on eBay so now in process of replacing most of the sill.
I say most as the the top half is rust free so decided to split the new sill and join it to the good metal. 
The inner sills are still good, just needed grinding off in places and I painted black magic rust inhibitor on them. 
If sills on your M49 /M59 are still good I would definitely recommend getting some oily /waxy substance pumped into them.
That's the next job to do on the 1.8i I'm working on.

[notsofast]

My M49 van's offside sill started showing some corrosion about 4-5 years ago, on the top where the sill meets the side panel, about 6-8 inches forward of the rear wheel arch.  My theory is this might have started due to wet loads in the cargo area, and condensation running down the inside of the side panel.

In December 2019 I had the area welded and resprayed by a bodyshop, who also said they waxoyled the joint from the inside (i.e. accessed it from inside the cargo area).  Not convinced they did this as well as they could have, as the paint on the outside again started bubbling a little this summer.  I didn't want to have it all re-done (not yet anyway), so I scraped out the worst pitting, treated the rest with Kurust and repainted with primer and touch-up paint.  The job was complicated a little by the existence of a factory sealant along the seam where the sill meets the side panel, which had to be re-sealed to prevent further water ingress.  As the sealant has to be paintable I used some tiger seal that I already opened a while back (I managed to scoop out some uncured and workable sealant from inside the tube - worked OK but somewhat fiddly/messy to apply this way....)

It will be interesting to see how my temporary DIY fix compares to the bodyshop job at keeping the bubbling at bay.

[Kieron G]

I guess anywhere that can hold water or damp muck will be a problem.
Can't really complain the Berlingo fairs better than any other older vehicle I've owned for corrosion by a long way.

[Gadgetman]

Does your Berlingo have a sliding rear door on that side?
There are issues with the door opening on these.

Mine also rusted through on the passenger side. It was rust held in place all the way. Cost me around £1000 t get it cut out, a new panel fitted and spray-painted with a colour-matched paint. The guy at the workshop was rather surprised that there was no 3rd party replacement panels for this... until he noticed the price. The OEM panel was about £100.

[Kieron G]

Yes this Berlingo has the sliding doors. ( I sold our 3 door multispace ).
The rust wasn't around the door opening but all along the bottom 3rd of the sill.
I opted to split the new sill and join to the good metal after removing the bottom half of the original sill. partly because I need use of the car most days and couldn't be without it at the moment.
I can see why a full sill replacement would cost £1000.
I paid £160 for both sills from a seller on Ebay

[Gadgetman]

The door opening lets the water in. Movement and any incline where you park the car decides where in the sill it rusts through first...

[geoff]

As Neil Young and Crazy Horse said " Rust Never Sleeps " ......