A4 fender rust

I have (2) 2002 golfs. I’ve cleaned behind those front liners every year. I’ve also had one fender replaced on each car about 7 or so years ago under the vw replacement plan. I now have a fender on each car that is rusting through at the bottom again. Being that these cars are close to 2 decades old, I am almost totally against spending $3k on each car to do this the right way. The reality is that all four fenders rockers would have to be done to really be able to get it perfect. I know the rocker is an “endcap” right behind the fender liner that is replaceable. My question is how structural is that part? I bet more than half the a4s around are driving with rust in that area (I look at everyone I run across). I pressed the lower portion of my fender with my thumb yesterday and put a small hole through it. Definitely a horrible design. Not much you can do other than clean stuff out as it just is always wet and moist in there. So for those of you that have this, what have you done. I’ve already done this repair once in each car and kind of feel frustrated with this at this point.

I clean and paint mine with POR 17 each summer, late spring. So far the fender bottoms are ok. I’ve also removed that rust causing foam block at the top of the wheel arch and painted that area with POR, in fact I’ve painted almost all of the back of the fender, and the area on the body in the wheel well immediately in front of the door.

I have some rust forming but I keep after it.

Aftermarket fenders are available for less than $100. We are talking an old car here. Certainly you could find someone to paint them? For far less than $3000. Just drop them off at the body shop, they come preprimed. Attach them yourself. 5 bolts on top of the fender, one at the bottom of the dogleg , one in the hinge area and a couple in the headlight area.

I posted the above comment in your duplicate thread and I see you asked for that to be deleted.

Thanks for the reply. I think the aftermarket fenders, from what eve read are a poor fit and need a lot of manipulation to fit properly. Not sure. Maybe I will go the route of replacing them myself though. They should in future cars have a tube that runs from the cowl straight through the bottom of the rocker so al this junk exits the area. This is pretty inevitable to happen though. I routinely cleaned this area out and my feeling is that once it gets moist in there and sits even for a short period, the paint starts deteriorating and that’s it. Just a matter of time at that point. My cars are daily drivers. My main gripe in having a shop do it, is the rest of the cars may have other spots that I’m unaware of at this point.

I bought an aftermarket fender several years ago, for my old 2000 Golf, after my daughter had contact with a guard rail and it fit fine. I forget where I bought it. ebay or rockauto one or the other.

I may do this in the spring. Quite frightening to have pushed that lower portion with my thumb and it just sunk in.....

I was able to badger the dealership to sell me 2 new primed fenders and hardware kit for $220.

Please explain....

My old TDI (99.5 Jetta) was in need of paint and the fenders were rusting. I stupidly missed the 12 year recall. I went to the dealer, sat down with the service manager and he agreed to drop the price a bit. Fact is those fenders are old stock and they can sell them for whatever they want. Got the fenders, hood and roof resprayed, car looked great for less than 2 years then got totalled, very sad. Depending on your needs you might be better off with some good used fenders (car-part.com) in the right color. Be sure to see the TSB when you install.

Another treatment to bare metal is: "rustbullet" sold by Summit Racing. Sold as silver or black.

I have been using in on Mk. II's and now, Mk. IV inner-fenders, pinch welds, inner rear fender behind filler necks, etc. Works like a champo…….make sure it CAN NOT come in contact with your eyes.....no joke.

I remove the wheel well liner twice a year, clean out any collected mud/dirt/leaves, and apply a coating of Fluid Film to the interior of the quarter panel (fender) and in the recess behind the wheel well liner.

You live in the rust belt...Winter salt will get in there. So do you clean off all that salt that will get in there???? If not than its to be expected.....

I do too. Take off fender liner spring and fall, clean out the muck and spray it with corrosion free (atleast before winter). Reinstall fender liner with two nylon washers for each bottom screw To serve as a crap gap. Oilhammer recently mentioned spraying flexseal on this area, which I believe is silicone.
After seeing the dealer applied black tar like protectant that hardens, and the rust that forms underneath, I’ve decided to take the routine maintenance approach.

I usually clean it out several times a year, but yes, I live in the rust belt, and yes, it’s still a poor design that traps everything inside.

I just drive with 1 rotted fender. The driver side is fine, for some reason.

Here we have had an attack by esthetics police, most probably spearheaded by body shops greedy for expensive repair work. It is now in the inspection criteria that you can't have perforations in body work, and repairs have to be "factory like" (the verbiage related to me). Just what constitutes factory like is up to the inspecting shop, but the state also has roving compliance officers, and heaven help you if that officer doesn't like your shop. Or rather, heaven help the clients that will be rejected for what appear to normal people as insignificant details.

Cheers,

PH

In 17 years I've replaced the front fenders on my Wagon twice. Once because the mud flaps rubbed the paint off, and the second time under VW's rust repair warranty because I neglected to keep the dirt out from the tops of the rockers. I just had my guru pull the fenders and POR 15 them, and epoxy the tops of the rockers so moisture wouldn't get in. I think I'm just buying time until I'll need the rockers repaired again. Fortunately I have a shop what's willing to do that work. Small price to pay for a car I don't want to give up.