I might just start off by saying that perhaps I am too keen to poke things with a screwdriver and perhaps some things are worth not knowing about?

Anyway, I wanted to be absolutely sure about the condition of my sills (here are my offside) so I poked them in various places and two failed.

That's pretty obvious where the new hole is and didn't hold up much resistance sadly. The area surrounding it seems to be fine. The next one is the sill end and there is a hole (just that the picture is awful). The hole about 1 mm in diameter so it is tiny but I fear it is a rusted from the inside out job.


For those who don't know I'm 16 with no knowledge of cars, but this is a learning curve. So what's the process for repairing a rusty sill?

 

Hey Seb,

Depending on har far it has gone, a new sill would be best. You can either patch it with a repair patch or replace the sill. You'll need to weld or have someone weld.

If you could weld, you'd start by removing the rust and seeing how far gone the area is. Cutting back as much rust and as little good metal as possible. When all the rust is removed, you'll want to weld on the repair patch/sill. Flood it on the inside with wax or some sort of rust protective stuff and then get it painted. Recommended is a good underfloor sealant which can be painted on, i order to stop stone chips causing more rust.

A good shop shouldn't charge mich. I cam get a sill replaced herr for around €150/side incl. paint afterwards.

 

I do want to get into welding as part of the project. My concern is while I start cutting sections of sill out, won't that comprimise the strength of the car and it'll start to crush in on itself?

And when you say "too far" is that if the rot spreads through the first flange (I think that's what it is called? The piece of metal that joins the inner and outer sill?)

 

The outer layer is rarely a carrying load bareing part. Like the wings...If you cut the roof off amd leave the doors open, then it'll bend

 

Dr Wilkes
You have a very interesting, but important and useful learning curve ahead of you. Just about everyone on here will confirm that doing the work yourself is the very best and most certain way to have it done properly. I know wealthy people who have spent substantial sums and still not got their XJSs running properly, people who really can diagnose and fix faults are rare as hens' teeth and getting rarer. But you CANNOT do it without being properly prepared. Go to the Local FE college and learn to weld properly. Find a kind soul to lend you a shed or the corner of a barn or an unused garage, enrol a friend to learn with you (the world is still full of car-mad guys and girls - the first date I had with my lovely wife she was helping me strip the shell of an Austin Healey Sprite), get the tools for Christmas and birthday presents. Get a part time job, you will be amazed how supportive people can be when they realise you have a project and a passion.
Then, one job at a time, fix the car. The car needs to be under cover, it will deteriorate faster than you can fix it outside. I am not trying to dissuade you, far from it, but on a big heavy car like this, you must be prepared, and you must have the tools and the time, and being under cover takes a huge load from the repairer's shoulders, makes things far less dangerous, and far more do-able.
Greg

 

Yep, I can only agree with Greg regarding on job at a time. Keep focussed on one job until completed. I my case, I've kept the front axle my main job, doing my engine "on the side". When the axle is back in place, then it is again back to the engine. Getting that ready to be slotted in, whilst purchasing parts to do the rear axle. When the engine is back in and running (important!), then the rear axle will be out...

Once I've done the mechanicals, it will be bodywork time.

 

Good advice from Greg and Damien.

If you own an XJS and don't have deep pockets you will need to learn to do most of the work yourself. And even deep pockets don't guarantee quality workmanship.

My brother spent $250K having someone restore a Shelby Mustang GT500 and it took him 2 years to iron out all the issues, and that's on top of the $250k.