Rust Alert! Clean behind your plastic fender inserts

[orange4boy]

Look what I found while replacing the transaxle in my Prius. I wasn't looking for it there if you were wondering. I had some time to pop these out. Took less than 5 minutes to get them out once the wheels are off. There was a few pounds of crap lodged in there. I carefully scooped out as much as I could and then hosed the rest out. Found a rust spot and bubbling paint which I will repair before undercoating it.

To remove the plastic clips, Pry under the inner disc with a smallish slot screwdriver or pry tool till it pops out about 1/4" then pry under the main disk and it should pop out. These are re useable. The rest of the screws are 10mm.

Nip this in the bud and your car will last many years longer.

Nasty



Nice:



Don't forget to clean under the fender lip too.

I plan to do the back fender wells also and seal them off better so this does not happen so quickly

[Frank Lee]

Those nooks are crannys kill your tin!

The best thing to do I suppose is seal it up good with oil, tar, whatever works. I've never done that but maybe some day before I die I'll get the hint and actually do what I know I should???

In the meantime I do know that some nooks and crannys can be blasted out with a pressure washer but the key is to know where they are and figure out access to that spot. The example I have in mind is on pickup trucks- ALL of them in this rust-belt region rot out above the rear wheelwells, because dirt/gravel and whatnot all pile up on top of the inner fender and nobody thinks to blast that out of there. I've been hosing that spot out since my truck was new in '94 and that is one place on my truck that isn't rotted out- but other trucks the same vintage in town are. Brand doesn't matter either in this instance. My truck is suffering rotted rockers under the extra cab and I found out that it occurred from the INSIDE out due to chunks of sound deadening foam stuffed in there that hold condensation.

People would probably wonder what I'm up to were they to watch me wash a vehicle. Most spend all their effort on the top side making it look good while I concentrate on the wheelwells and underside bits.

[thatguitarguy]

I've always been horrified looking inside wheel wells. Except for the plastic shields, they look like they are made to catch crap and store it to rot the vehicle away. I wonder if filling these spaces with something like "Great Stuff" would keep all the crap out, or is this the same as the sound deadening foam that traps condensation??

[orange4boy]

I wonder if filling these spaces with something like "Great Stuff" would keep all the crap out, or is this the same as the sound deadening foam that traps condensation??

I tried that years ago but it just got waterlogged. Try removing that stuff from nooks and crannies.

The best thing is to leave the sheet metal stock and undercoat it. As long as it can dry out from time to time, your car won't rust. Garaging is the best if you can. It's also possible to improve /add to the stock plastic fender liners so less crap gets in behind.

In the meantime I do know that some nooks and crannys can be blasted out with a pressure washer

I have been warned not to use a pressure washer because it forces water into places it shouldn't go. That said, If you're careful and don't aim it at, say, the fuel injectors, it's still better than leaving the gunk in.

Anyone have a favourite DIY undercoating?

[rkcarguy]

I purchased a car which had some good buildup behind the front tires, such that a small tree was starting grow out of the mud flap/fender seam behind the front wheel! I removed the mudflap and simply washed it out with a garden sprayer. Thankfully no rust or paint bubbling had occured.

[orange4boy]

a small tree was starting grow out of the mud flap/fender seam behind the front wheel!

That's funny. How eco is that? Growing it's own carbon sink.

It reminded me of my teens and Dad's old Volare station wagon which he drove till it was literally falling apart but still ran. One fall day I borrowed it and there was a crop of mushrooms growing in the passenger foot well. The car was returning to the earth but the slant-6 was still kicking.

[ChrstphrR]

When I had to replace one of my inner fenders on Greta, my TDI Jetta in 2008, I found out that all the pine needles that fell in by the windshield wipers eventually made it through to that cranny between the firewall and the inner fender. ... to the tune of about 1-2 pounds of pine needles and trapped dust.



Per side! Yes, as soon as I found out the bad, cracked inner fender had this, I went and changed the good side too. Around 4 pounds of extra weight trapped in where you couldn't see.



The good news - Not too much for rust, considering what WAS back there, for up to 8 years before it was found...



But thanks for the reminder, come spring, I'll tackle this again, and finish rustproofing the metal tangs where the inner fender bolts on again, to be thorough.

[orange4boy]

EEWWWWW! Grody to the max! Nice to get it clean though huh?

I think I dug out a couple of pounds per side of mostly black road sand and scunge.

I just picked up can of Rustguard rocker panel coating and a can of under coating. Will try to get to it tomorrow but I'm also finishing up the tranny installation so that's the priority.

I'm still trying to figure out the best way to seal it up better but I have the same problem of the cowl draining into that cavity. Hmmm.

[bgd73]

great tip.

my old sube does this, or it used to. it seems steel wheels carry a signal to cram things there, it has not built up since alloys 1/2 wider installed. I assume steel warmth makes things invisible, creates paths in other words...


a hammer of flying debris...chemistry included.

[JonnyG]

I've noticed that I'm starting to get rust where the plastic rests against the fender, but no rust underneath the plastic. It's a very small amount and I can't figure out how it started. Rubbing maybe? Any thoughts?