Z3 silly question (with pics)

[Zeddicus]

Oops can’t edit title but silly=sill. Stupid autocorrect!!

Hello,
Making advance prep for MoT at beginning of October.
There’s a patch of rust on the drivers side sill of the 2001 (facelift) 1.9i Z3 I’m picking up next week.

I wondered if someone could confirm a few things for me.
I took these pics to a local body shop & they said (ballpark figures) that to fit & spray a replacement sill would be in region of £700. And to weld in a patch (if damage wasn’t too bad) would be in region of £275.
Also advised that sill damage was structural (if it’s penetrated the metal)

Does all this sound correct?
If damage isn’t too severe is there a cost effective alternative to welding a patch in?

Can I buy one prepainted black and fit myself?
If so what’s the official name for this part?

Pics attached (I hope). Lots of reflections.

 

[t-tony]

That is a bolt on part and is not a structural part of the car. Unless it has a projection or sharp edge which could cause injury it is not a testable item.

Tony.

 

[Zeddicus]

Thank you. Body shop man disagreed. If it’s non structural then I can fill and paint as I see fit?

 

[stevie_a]

I am no expert in this bag sure somebody will correct me if I am wrong !

all Z3 body panels,including the sill just unbolt,

 

[stevie_a]

I stole this image from another website, you can clearly see the sill and the wing unbolted

 

[t-tony]

And that means they're not structural. The seat belts are bolted to the structure inside of the body. Tell you body man to go on an MOT testers course.. if he still disagrees tell him to contact me.

Tony.

 

[andyglym]

Nonsense. Circa £110 per side less paint.

 

[stevie_a]

 

[Dino D]

Go to another body shop, seriously this one sounds like a rip off (or maybe he’s just never seen a Z3 before but even then should be able to figure it out by looking at the BOLTS that hold the sill cover to the car )

 

[Sean d]

That sill is tossed and really needs replacing, you could fill and paint it but it won't last 5 minutes, it would be well advised to remove it and take a good look at whats on the innner sill, this is the part that is structural, for some reason some rot a lot and others barely rust at all, this is one that I have just sorted

during

done

 

[mrscalex]

I’d tread a little cautiously here.

It’s 100% true it’s not an MOT item. And you have also been quoted more money than you need to pay.

But these things normally rot from the inside out. So Sean is also right to warn you about getting the cover off to check - easy enough btw.

It could be hiding something nasty on the structural sill underneath. Fortunately most rust found on the inner sill is surface rust and can be treated. Preferably with Por-15 or similar. Sean was unlucky to discover what he did.

 

[Mazza]

Mine had some surface rust on the inside of the sill, which came off with a wire brush. Treated the areas with a phosphate paint, which turned the rust black, and then red oxide and a top coat. ( cant see the quality of my painting when its bolted back on...luckily )
You need to remove the front wing panel as there are a couple of fixings you need to get to, and just loosen the rear wing down the edge of the door to get to a bolt that is behind it.
You may need some replacement clips as they often get broken when removing all the trim parts from the door area to get to the 3 bolts underneath the trim.

 

[roadvoyager1]

As others have said the sill cover needs to come off and the inner sill, which is structural, needs checking and repairing if needed.
Normally, corrosion is in the areas subject to stone chips, particularly the sill ends where they are in the wheel arch. The rust you show is not a stone chip area and may be due to some damage and repair earlier in the cars life. All the more reason to check the condition of the inner sill.
I replaced both of my outer sills and front wings last year for under £500. I fiited them myself but painting was done by a bodyshop to my specification. The £700 for one sill is way over the top, total labour should be no more than 4hrs, although there will be more time than that waiting for paint to dry.
The underside of the outer sill panel, including the return flanges in the wheel arch, should be protected with a stone chip protection paint (PVC or PU) before it is painted with primer, basecoat and clearcoat. I also painted the inside face with waxoyl before it was refitted.
For the inner sill; remove the jack pads and take off all of the loose rust. If the sill is perforated it will need welding, but on most it is just surface rust. Treat the rust with your preferred product (POR15 is favoured by many on the forum). I also sprayed inside the inner sill with a protective wax. There are a couple of drain holes (embossed areas) where the sill is fixed to the underfloor. Use the end of a cable tie or similar non metallic poker to ensure they are clear. I also replaced all if the fixing bolts, which is not really necessary.

 

[Zeddicus]

So many helpful responses thank you (and i appreciated the pictures / videos).
Some follow up questions:

I found this guide...
https://zroadster.org/articles/bmw-z3-sill-removal-and-protection.67/
Is appropriate to my model?
It looks to be within my capabilities (as an ex 110 Land Rover owner), but I’ve sometimes been defeated by hard to get at bolts... and particularly broken trim fittings etc (not the clips and bolts themselves, but the tired bits they attach to!
Assuming i can remove everything without too much trouble, I’m happy to sand, grind a little, and paint / treat.

It does sound as though it’s worth removing the sill... even if only to convince myself there’s nothing too bad lurking behind.
The current owner (a relative) has had the car for around 10 years, so whatever it is it’s taken its time developing.

From painting perspective, will it be best to fit the new one first, and then take it somewhere for painting? (Not just get it sprayed bmw black first? I thought that might be cheaper.

Can anyone point me at a reasonable supplier of a drivers side sill
and also the trim clips that i’m probably going to break a few of.

 

[roadvoyager1]

Get your new sill from your BMW dealer and ask for 10% discount. They nearly all give the discount if you are a BMWCC member and will often apply it if you mention this forum.
You will almost certainly break some trim clips and these are available on ebay or from BMW.
Have a look on realoem for part numbers using your VINnumber to get the correct model details
https://www.realoem.com/bmw/enUS/select

 

[roadvoyager1]

For painting, opinions will certainly differ. Best for colour match is to paint on the body, however, as yours is black and non- metallic any good bodyshop should be able to get a good enough match spraying off the body. For applying rust protection off body painting makes it easier. The final paint finish is better heat cured (typically up to 80 deg C) and if you have carefully applied wax etc. to the inner it could well be affected. So for painting on the body you will need to make sure you carefully choose the protection products you use.
Basically, either option is viable if you chose the correct products.

 

[colb]

All good and valid advice on here, what you have been quoted is certainly over the top for one sill. If you can take a Landrover to bits the BMW sills will be a doddle. Best take the outers off and see what condition the inners are and treat if corroded. I did mine last year and posted pictures over on the other forum here https://www.zroadster.net/forum/viewtopic.php?f=5&t=45073&p=415842&hilit=sills#p415422

 

[mrscalex]

Definitely have it sprayed off the car. They will get a good colour match off the old one unless they are complete numpties.

It doesn't need to be blended with adjacent panels - that would be a massive job. The paint job will be much neater on the edges of the sill cover and it will avoid a load of masking up and risk of over spray on the car body. Plus you haven't got to leave the car there.

 

[Sp02zbr]

I had both mine supplied and painte

r by BMW for £270.

I then wrapped them in clear paint protect film

 

[allen]

I had both mine supplied and painteView attachment 88304 r by BMW for £270.

I then wrapped them in clear paint protect film

where was these from mate?