Wheel arch liner sealing strips

Hi I'm refitting the plastic liners to the front wheel arches of my 1999 C2 and have bought some new fixings, rubber lip, air ducts and also these self adhesive foam sealing strips (items 9 and 10 in the D911 diagram) : https://www.design911.co.uk/pages/diagramsBrowser.aspx?categoryID=8&diagramID=2680# There weren't any strips on the car when I removed the liners and I'm trying to work out in what position they should be fitted. Stuck to the wheel arch or the plastic liner? Can anyone offer any guidance? Many thanks

I recently removed all the under body plastics to check / clean / waxoil and noted they were stuck to the front wings just inside the rolled edge of the wing , I expect to stop rubbing / rattling. I did wonder if the bilt hambler wax would melt them over time - I guess we'll see!!

What exactly were you waxoiling under there?

Here it is....near fuel filler

Waxoiled everything!! Inside of wings got a light misting. Exposed bits had a liberal coating as did sills and box sections on floor pan. Basically checking for trapped crud and rust. Got 1 kg of crud from behind one of the rear arch liners. Fronts had a bit at the rear / start of sill. Luckily minimal rust. Regards Ian

Brilliant! Thank you Ian. Sounds like I am on the same mission as you cleaning, de-rusting and protecting. How are you finding the bolt hamber stuff? I think it's great to use. Hopefully the longevity will be just as good

The Bilt rustproofing range recommended by a friend restoring a classic mini. All the tubes etc worked well. A tip from my dearly departed father was to put in hot water first to thin and aid application. Hardly any rust found - mainly where plastic liners had rubbed - couple of spots in front arches and the seam in the centre of the rear arch. Also three spots either side of the floor box sections. Looks like manual weld points as too many layers to spot weld. Sills / sill plugs were spotless. Resealed the rears with tigerseal (cheap at ECP) where I had to cut them out of the seam sealer. I buzzed off the rust with the dremmel, kurust, zinc 182 and black hammerite (car slate grey). Several new trim clips, self tappers etc replaced the two wood screws used on the front arch liner Over all pleasantly surprised how clean it was for 17 years old. Ian

Good stuff Ian. Sounds like you've found the rust in similar places to me. All in all not too bad though. Worst bits on my car are rear arches where they meet the sill. I have the aero kit and there was an awful lot of crud hiding behind the side skirt/arch liner. It all feels solid though so I'm hoping I've caught it in time. It's going into the bodyshop soon for some other bits and pieces so I'll get them to attend to the rust at the same time. Just hope there's no other nasties hiding behind the side skirts!

I scrapped out a load of crud from inside my wheel liners as well and noticed a couple of small patches of rust 1cm ish. What's the recommended procedure for treating this sort of rust....I've never attempted to fix anything like this before.

Most of what I found was superficial rust. My method was buzz over with a wire wheel in a cordless drill to remove all rust leaving clean metal, degrease/panel wipe, zinc primer (I used bilt hamber electrox), seam sealer in areas where I'd removed any of the factory sealer, prime again, two coats stonechip paint (I used upol gravitex), bilt hamber dynax uc sprayed over everything I could to provide ongoing anti-corrosion protection. You could put a top coat of metal paint (hammerite or similar) over the stonechip to make it look prettier. I'll probably do this in the future in combination with a suspension overhaul. You could also incorporate a rust conversion stage if you can't remove all with the wire wheel. Something like bilt hamber deox or hydrate 80.

Did you say they were foam? Good for trapping moisture in then, common on VW/Audi etc as they have a foam block in the inner wheel arch that basically causes the arch rust that is so common.

It's not really like a water holding foam. More like a sort of soft rubber. E46s are notorious for having the arches rust out due to the liner rubbing on the inside lip. So you can't win either way. I removed all my liners recently as the visible areas in the front arches were in a terrible state. The fronts are only stonechip coated to half way up so I stripped them back to bare metal, treated the rust then primed, stone chipped, seam sealed and top coated. I'm in 2 minds about sticking a wax protection coat on as it dries out over time and creates a right mess. The rears seem to be quite common for rust on these but mine were solid in the places they usually start rusting. However, my jacking points were a right mess and subsequently I found splits in the thick stone chip coating along the sill pinch weld. Water was sitting in behind this rusting the steel from the outside. I pulled all this off and have given it the same treatment. It did make me wonder how bad that area could get on aero cars. Be very easy not to notice until one day the skirt falls off with what remains of the sill attached.

...vis a vis 996s and rust; no doubt in my mind that the worst effected will be aero kit cars...years and years of water ,salt and crud sitting behind the sill skirts is a guaranteed recipe for some serious oxidation !

Underside plastics I am thing the same thing at the moment, started with seeing a little rust around the rear jacking points, I now have all the plastics off and making sure all rust is removed and repaired before protecting. Has anyone found a bulk source for the fittings, such as the sheet metal nuts (speed nuts), and screws, I have been checking placed like Wurth and can't find an exact match? I just wanted to check before paying OEM individual prices.

I've bought bulk packs of screws and nuts from eBay for my VWs and these are the same size as needed for 996 so I've replaced with those when I've been doing maintenance. Some specific clips and nuts I have got from OPC though. One place to check which has had rust on my 1998 C2 is on the top rear of the rear arches where the muffler bracket attaches. It's 3 layers of metal with the stud that attaches the bracket welded in as the centre layer. With the layers it seems to attract rust and on one side of mine had corroded so that the stud broke when I was removing the nut holding the bracket in place. Maybe if it had been treated earlier that could have been avoided. Also rear wheel arch to front sill section has got corrosion on mine, again an area that might be avoided if treated