Rust on a frame

[tomas_v]

Was changing wheels on my 2011 A4 and noticed quite a lot of rust on a car frame (not body or suspension parts)
Is it normal? Should I be concerned? Do something about it?
Hope you all can see rust in these photos.
http://imgur.com/a/Qt1qK

[Lemonslap]

My S4 has this rust on the subframe, I was told from my main dealer that it isn't covered due to being a "consumable part"?? I really hate dealing with these clueless people..

[green A8]

As you're based in Norway I've no idea what your yearly vehicle test requirements are regarding corrosion. In the UK the rust you've pictured would be classed as surface rust. It might get mentioned at MOT time as an advisory, but it would appear to be just a minor surface rust issue at the moment. But once started it will only get worse.

That said. if that was my car, I'd be looking at removing the surface rust using wire brushes or whatever is required, and getting some sort of protection in the form of either anti rust paint or anti rust compound. Over the years I've used quite a few products from many different companies. For the last few years I've been using Bilt Hamber's excellent range of products, check out their website via Google search for further details. I'm pretty sure that they will be able to export their products over to you in Norway. At this point I must point out that I am in no way connected with this company, I simply use their products and reccomend them to others as they do seem to keep rust in check. Audi's front and rear subframes/axles do seem to be somewhat rust prone. That said they're nowhere near as bad as some other's I could mention.


Hope this helps.

[Crasher]

Yes, totally normal for Audi's since I have worked on them for the last 33 years. I remember reading in a magazine before the type 44 Audi 100 came out in 83 with its galvanised shell that thy were working feverishly on rust of under body components too but that must have failed or been abandoned, all thy still gt is a whisper tin coat of paint, not even powdercoat! Mind you, powdercoated subframes were a disaster on Jags, they rotted away under the powercoat but the coating hid this, quite scary! I have been under a 2011 8K A4 today and there is rust around the edges of almost every steel underbody components.

[green A8]

Good point 'bout the subframes only getting a very thin lick of paint Crasher. Next time I have an Audi on my ramp I'll get the paint depth gauge out and measure just how little or how much paint is slapped on at Audi. I doubt it'll be more than a few microns. My old A8 D2 is the exception to the rule as I dropped both front subframe and rear axle assembly dismantled the lot had every steel part shot blasted then repainted everything with good old hammerite. I also injected Bilt hamber products into whatever cavities I could. But as I intend to keep that old beast for ever (It's still the best driving Audi I've ever had the pleasure of owning). I thought it was well worth the effort. I've yet to investigate the underside of my A8 D4 as it's under warranty i'll let Audi worry about that for the time being.

[Crasher]

We are doing quite a lot of resto work at the moment and we take all the ferrous bits for blast and powdercoat, I just had a huge pile done for a Mk2 restomod. This is just a small selection, I even took the steels out of the number bumpers and had them done.

[green A8]

That's an impressive pile of powdercoat Crasher. How do you get on with re-assembly? I found PC to be vunerable to scratching/chipping on rebuild also it seems to be very stone chip prone. A pal of mine has a fully restored Stag that had a fully PC'd suspension fitted a couple of years ago, it's now starting to look frayed around the edges again after less than 2,000 miles use. That was the only reason I chose to paint my A8 bits really.

You're not restoring a GTi are you? If so look under the plastic wheel arch trims and get your mig/tig out! I repaired an 89/90 Jetta GTi a year or so ago. Really tidy looking low miled car, right up to the point we removed one of the rear wheel arch trims to investigate a few minor bubbles. It then turned into a rot box. I spent a happy few hours grinding out the rot and tigging on new panels. The inner arches were also moth eaten so I fabricated new ones from scratch on the english wheel and fitted those whilst I was at it. The Jetta survived it's surgery and returned to roadworthy status, only to be written off a few months later when a tree fell on it's garage

[Crasher]

It's very tough, much less prone to handling damage than even blasted bare steel that has been primed and painted with Eastwood chassis black. I do wheel bearing hubs that way with Wurth 1K etch then POR 15 engine enamel as a powder coated hub is an absolute pain to get the powdercoat out of areas you don't want it and masking is impractical. I have been doing this for years and everything, even springs and the stuff my chap uses is flexible but tough, I have no idea what it is. The aforementioned Eastwood powedercoat is the next best thing when you want to spray it from a can and now they are doing two pack in cans! Jaguar did have a terrible problem with cracking and lifting powdercoat as I said and it made subframes rot away but you could not see it.

I spent literally months and months letting in new sills, inner and outer rear arches, fuel filler flap area repair panel rear panel, floorpan edges etc etc and then flame stripped the complete floor and inner wings to bare steel (when I found more rust) and then wire wheel buffed the entire area, treated and surface rust by spot blasting, Jenolite and rust primer and then etch primed, sealed, stone guarded and then base coat and clear. Next is 12 litres of Dinitrol inside the box sections. It also had a new tailgate, doors, wings and bonnet.




Floor in etch

[green A8]

Now that's a top job Crasher. Nice to see someone doing the job properly I doff my cap to you sir. The Jetta wasn't restored to that standard I have to admit, but then it was a tidy old motor before it got squashed. I was unaware that you could buy an inner wheel arch panel 'off the shelf' so I fabricated my own repair section, up to the seam that lurks roughly mid way in the arch in one of your photos, oddly the main rot in this area was well away fron the sill area.

Green tail lights? Hmmm interesting...Not seen those before I did see a Golf fail it's MOT with blue tail lights fited, not sure if the lights were the cause of the MOT fail though. Seen plenty of blacked out ones. The MOT examiner I go to hates 'em.


At some point in the near future, when I'm feeling brave. I'll start restoring my only non Audi. A 1988 Passat B2 1.8 GT Estate, It's only had two other owners and done just over 50K miles. The Golf GTI engine an gearbox are sweet as. Problem is it 's a rot box and will need many hours of welding. I was told that there are only a few of these left on the road. No blooming wonder, they decay on some very strange places. (Corner of bulkhead where inner wings are welded on, and tailgate hinge area) I'm also trying to locate what panels I can. Out of interst Crasher where do you get your panels? I feel a trip to the Fatherland coming on, as I'm after floorpans and inner wings as well as the usual Sills and outer wings. If I can't get 'em I'll have to fabricate my own.

[Crasher]

Hmmmm, those lights. I tried to convince him to go for a more modern look like the clear glass or smoke LED but my pleading was ignored so I polished and clear lacquered the glass and tidied up the outer plastic with a tickle of Wurth fine texture paint and a wash coat of their RAL 9005 satin Black. These are ultra modern and I suppose that isn't what he wants, he prefers the 90's look and that is when I sold him those lights, back in the early 1990's at GTI International, the Hella red, blue, green, yellow and full smoke rear lights were really big sellers.