Should a 2005 Audi A6 (C6) be rusting this badly?

**Ryan M** · 21-04-2018,02:31 PM

Hey guys I picked up a '2005 Audi A6 C6' a couple of months ago and I'm wondering if the C6's are notorious for rusting on the bottom of the doors, rear arches, sills or have I just got a lemon car. I knew about the rust on the sills and plan to fix it but on further inspections and when cleaning the car I've noticed a whole lot more that would've put me off the car when purchasing. Myself and the car are located in Scotland where the council uses to much salt during the winter months so that has probably made a big difference.

All my doors, sills and arches have rust on them and I'm unsure what to-do about the problem, either spending a tonne of money or just selling it and buying something better in my price range without rust. I do love the car and the C6's in general but the only gripe I have with the car is the rust present on the vehicle.

Full Imgur album: https://imgur.com/a/wlopKk6

I've attached a few pictures of the rust problems below but will include the full album to avoid posting 30+ pictures:

**Amo Zirins** · 21-04-2018,02:34 PM

Originally Posted by Ryan M

Hey guys I picked up a '2005 Audi A6 C6' a couple of months ago and I'm wondering if the C6's are notorious for rusting on the bottom of the doors, rear arches, sills or have I just got a lemon car. I knew about the rust on the sills and plan to fix it but on further inspections and when cleaning the car I've noticed a whole lot more that would've put me off the car when purchasing. Myself and the car are located in Scotland where the council uses to much salt during the winter months so that has probably made a big difference.

All my doors, sills and arches have rust on them and I'm unsure what to-do about the problem, either spending a tonne of money or just selling it and buying something better in my price range without rust. I do love the car and the C6's in general but the only gripe I have with the car is the rust present on the vehicle.

Full Imgur album: https://imgur.com/a/wlopKk6

I've attached a few pictures of the rust problems below but will include the full album to avoid posting 30+ pictures:

I’ve had a same problem with mu A6 C6 2005 avant. Was starting bubbling like motherf.... so sold it before it pops

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**Rob69** · 21-04-2018,03:20 PM

yours is slightly worse than the rust that was coming through on my B5 2005 passat, nice moisture trapping trim on the doors, they are 13 year old cars though. What is like underneath - subframes etc ?

**Ryan M** · 21-04-2018,03:36 PM

Originally Posted by Rob69

yours is slightly worse than the rust that was coming through on my B5 2005 passat, nice moisture trapping trim on the doors, they are 13 year old cars though. What is like underneath - subframes etc ?

The underside is actually ok for its mileage and with it being driven in Scotland surprisingly good. I had a good look under when my more mechanically driven friends changed the clutch and flywheel. Weird how the underside has stood the test of time, but the exterior is showing signs of rust. I'm guessing it's not a surprise for a 175k mile car which I only paid £2000 for.

Would the door rust be easy to rectify Rob depending on how rusty it is, grind down and paint?

**Rob69** · 21-04-2018,05:01 PM

That'd be a labour of love and it always comes back through soon enough - in my opinion!!

**B5NUT** · 21-04-2018,07:08 PM

My A6 was the same, so it went in the Audi scrappage scheme. It was worse than your car, it had rust in the same places plus both sill's were rotten.

**Ryan M** · 22-04-2018,01:15 AM

I'm surprised to hear your vehicle was like this @B5NUT. Your car always looked nice and presentable from the thread you done over on Audi-Sport. I knew you had issues on the sills from the A6 Facebook group but didn't realise that your doors and other areas were effected by rust. I'm not in a position to either buy a new car with the scrappage scheme or buy a new car in general so I'll need to hopefully get it fixed during the summer. Do you have any photo's of the rust on your vehicle @B5NUT?

Edit: Forgot to mention that the underside of my wheel arches are the same as you and I'll hopefully be following the same method to combat it under the arches.

**lynalldiscovery** · 22-04-2018,08:06 AM

I think the doors can be an easy fix/bodge get some aerosol chain/wire rope lube and spray inside the door, the lube will work its way out and stop it getting any worse.
The wing rot again grease but this time wheel bearing grease and a big dob on the inside will stop it dead.

Every time I am under any of our cars and see rust/rusty pipe/bolt/union it gets a blast from the aerosol, it lasts a long time

I had the same issues with a merc w210 model and the wifes merc w203 both proper rot bags, grease slowed the 210 rot down but the end was nigh, luckily for me it got totalled, the 203 actually lasted well with the grease. so well it was still sound 3 yrs later when it got traded in.

**B5NUT** · 22-04-2018,09:43 AM

Originally Posted by Ryan M

I'm surprised to hear your vehicle was like this @B5NUT. Your car always looked nice and presentable from the thread you done over on Audi-Sport. I knew you had issues on the sills from the A6 Facebook group but didn't realise that your doors and other areas were effected by rust. I'm not in a position to either buy a new car with the scrappage scheme or buy a new car in general so I'll need to hopefully get it fixed during the summer. Do you have any photo's of the rust on your vehicle @B5NUT?

Edit: Forgot to mention that the underside of my wheel arches are the same as you and I'll hopefully be following the same method to combat it under the arches.

The outside did look good from a distance but when you got close up, you could see the issues. Above the windscreen had the same sort of damage, and there was a small amount of bubbling on the rear wheel arch. The inside of the doors were all starting to go same as the OP's. The tailgate I had fixed however a year later the rust started to come back, so it was clear that a new tailgate was required.

I cleaned up the inside of the arches as they were badly corroded and the rust was still gone after a year. The sill's however were a different story. Well before I got the car someone jacked up the car on the sill and damaged both sides, water had clearly got in and rotted them from inside out. I had a sill from a breaker cut away and welded onto my car but after a couple of years it was coming back and needed a new sill but at £900 each + pro welding and paint I was looking at a £3K bill.

Mrs B5 wanted a smaller car and I got the C7 so it was time to let the C6 go, and the scrappage deal was too good to pass up.

**Rob69** · 22-04-2018,10:43 AM

My B5 passat looked tidy but getting up closer the bubbling was there and doors were similar to OP photos, it hadn't broken out through the paint but it was only a matter of time, I'm not really interested in chasing rust and fiddling with paint so just lived with it until the car was sold on. Ican't say I was too disappointed though for 13 years old and mixed ownership / care.