FD3S Common rust areas
 

I did a light search of the 3rd Gen area and didn't come up with a whole lot.

I'd like to make a thread that deals with all the rust & corrosion areas (common and otherwise) that are particular to the 3rd Gen FD RX-7. Reason being, the cars are getting older now and this becomes more of an issue as they age.

Maybe some common areas you've found, how you treated/prevented it, and where to look to see if your car has any hidden signs of rust forming that you dont know about or did not think to check.

I will start off, and add some pictures in the next post.

Areas I've noticed to be common:

*Under the rear tail lights in the body (where the bumper cover meets and screws down) water can pool and begin rust without you seeing it. The rear bumper cover bolts under the tail lights can also rust up and strip the heads if not treated/prevented.



*Removal of the rear bumper cover exposes some steel tabs on the back of the unibody which are spot welded on, and water often collects/drains and forms rust where you cannot see it.



*side view mirrors attaching bolts can become corroded. Twist the side view mirror to expose the bolts and address this problem.



*water drainage channels along the sides of the rear hatch can become clogged or full of mud and debris from rain runoff from the roof. I have seen rust in these channels to the point where the rear guards are nearly falling off the car. These channels drain into the area under/behind the tail lights, further exacerbating rust in those areas.



*When the rear hatch is opened during rain/wet weather, water can run off and into the trunk area, where it eventually settles in the lowest point- the spare wheel well. This then leads to rusting of the spare wheel well as it is not often checked and dried out.



*There are plastic strips along the tops of the door openings, where the roof meets the door opening. Removing these plastic strips exposes a pinchweld seam which sometimes can have water trapped behind the plastic, along with debris, which can lead to seam rusting over time.



*Opening the hood reveals flat areas near the hood hinges, where water can drain into small holes and then down into cavities behind the front guards. Rust can form in these cavities on the unibody itself.



*The usual leaking windshield/heater core can lead to water pooling under the thick carpet/foam insulation in the footwells, which can cause the carpet to rot and smell odd, the windows to fog up and ultimately floor rust where some strengthener ribs in the floor are spot welded to the floorpan.



*Under the bottoms of each door are small water drainage holes for water to drain from the window glass runoff. Over time, silt and muddy debris builds up in the bottoms of the doors and these small drainage holes become clogged, leading to rust forming in the bottoms of the doors.



*In the rear hatch (as my car is starting to show) some people remove the rear spoiler and forget to plug the mounting holes left behind. Rainwater enters the insides of the rear hatch and rusts it from the inside out, and also pools in the hatch plastics, and then leaks out into the trunk, to ultimately find its way into the spare wheel well, causing rust in that area as well.




That is all I can think of for now. I aim to take photos of all these points shortly and compile a list, and then describe some of the preventative actions that are possible to stop the onset of the rust issues.

:)

Anything under the car needs treatment or looked at of course. The only main rust issues I've had was top of gas tank fuel tree, and the bolts in that area need to be replaces ASAP. All were rusted really bad. Next biggest rust issue I've had was the rear sway bar mount brackets. I broke one rusted bolt into the chassis for that bracket and was considered one of the most PITA problems I've had to deal with.

I'd say any bolts that haven't been turned in 20 years most likely will give issues. Caution on messing with the old stuff. My side mirrors are faded badly and I want to remove them for paint. The screws holding it in will not move, very scared to strip them since their Phillips heads and stripped most Phillips screws on this car.

Cavity at the rear of the front wheel arches. They rust from the inside out, only way to identify is to either remove the underseal or poke it with a screwdriver.

Front of the rear wheel arch, At the bottom where the inside wheel arch joins the rest, common rust spot.

Front seatbelt mount cavities rust.

Sills rust.

Rear box sections rust, the ones that make up the structure of the rear end.

I'd recommend using a cavity nozzle to inject a good rust converter (I use FE-123), followed by a decent rust proofing cavity wax like Dinitrol. Its a bit of a pain doing all the cavities, there are plenty of them and its a messy job, but its definitely worth doing imo.

Mmmm electronic rust pertection. The under side of my car is the same as it came out of the factory

You believe they work? I've seen quite a few independent tests that show they only work under certain lab conditions and not in the real world.

The main reason we get issues in the UK is due to all the salt put down on the roads in the winter, so UK cars like mine that have been driving on the salt for 20 years suffer. I've spent the last year cutting out rust and welding in new steel & now I can finally say my car is rust free :D.

The best protection imo is a decent coat of something like epoxy mastic, I've done my entire underside in the stuff, should be good for 30 years or more :)..

My rust Issues:

1) R door sill under aluminum trim.

2) Above L door trim (arched area) a rust bubble appeared. It seem to originate from a spot weld on the inside of the frame.

3) Front of rear wheel well.

4) Under rubber weather seal for trunk lid.

For those with the battery relocated to the interior this may be a contributor to corrosion in certain areas.

Well my car is Imported from japan so at a guess I would say it spent 2 months at sea/ salty environment when it got here it had surface rust on the head light frame and the top of the hatch. First thing I did was get a new battery and reconnect the rust stopper( battery removed for importing) those spots are the same as the day it got here. My new wrx has one so yes I do think they work

Under the car where the fuel rail plastics bolt up to the car

Nice to get some discussion going :)

For rust prevention, I prefer to use "Valvoline Tectyl 506" which is basically a cavity wax (brown aerosol application) that repels water and seals things off with a hard, thick waxy coating. Also good, it can be removed at any time later with paint thinner if you need to, without adversely affecting the surface underneath. I used this stuff on the tops of the side view mirrors phillips head screws a few years ago, and the screw heads are still perfect (albeit covered in brown wax) :p

Here's a link:

Valvoline Tectyl 506 Rust Preventative, 400g - Supercheap Auto Australia



I have found that a lot of the "sound deadener in a can" IE the spray-on thick bitumenous black coatings from auto stores can actually hurt more than help- they dry to be porous and can hold water and moisture in them once dry, and hold it close to the steel for long periods, encouraging rust to start...

What I like to do is spray on the cavity wax first, allow it to dry completely, and then use the spray-on sound deadener/mastic/bitumenous black stuff over the top.

Also, fish oil is very good stuff to apply as it will "creep" into seams and spot welded gaps and then dry hard and seal air and moisture from getting in there. Downside is the car will smell odd for a while afterwards and it can take a while to dry...

Another good product is something called "Penetrol Anti Rust Treatment" made by Flood
This stuff is basically like super fish oil in that it will even creep uphill, into seams and gaps and spot weld areas and then sets hard and traps out air and moisture. Downside is that you cant paint anything but enamel over the top of it. It seems to react when sprayed with acrylic lacquers. But it is very good stuff anyways.

Not sure that it's available outside Aus, but here's a link for some good reading:

http://www.floodaustralia.net/produc...-anti_rust.php

Getting into areas like the sills and other boxed cavities can be difficult, but there is a long attachment you can buy for spray guns which is basically a long pipe with small holes radially around it. This can be fed into the sill and then fired, coating the insides of the sills properly.

Some of my friends used to attempt to fire the hardware grade 'Space-Invader' polyurethane foams into the sills and box sections of their cars for supposed increased strength. They later regretted it as the stuff is "open-celled foam", meaning it can take in and hold water in the sills and box sections and start rust. And its flammable. If you ever have the need to foam fill a hollow box section, be sure to use the automotive-grade polyurethane 2-part foam, which dries closed cell and does not trap water :)

I have just this week been doing a bit of rust prevention on my FD.

Iv had my car for about 7 years now, and my biggest trouble spot is the rear tyre well. Not the actual wheel well, that's still got a good coat of paint & sound deadening, but the threaded hole where the bolt goes in to secure the rear tyre..that was starting to look like i should give it some attention..

Anyway i put a nice new 316 stainless bolt in there to clear out a bit of the rust, then i used CRC rust converter in the hole, then I applied white zinc over that..
Should last forever now! :icon_tup:

Also my the metal cover in the boot that covers the fuel pump, mines pretty rusty from having wet carpet sitting on it (from my hatch leaking somewhere)
Iv got a good secondhand replacement one of those to install this weekend..will probably add zinc spray or glav spray to it to make it more rust resistant :nod:

Oh also under my battery tray(on the cross member & the chassis rail), that was starting to look like I should do some preventative maintenance..gave that the same treatment (rust converter then zinc spray) :icon_tup:

I've always wondered if that zinc spray actually does work? Have you had good results with it?

I haven’t really used it before quite honestly, but im quite confident it will be good. It sure looks nice, but time will tell.
Supposedly it can handle outdoor conditions so should be fine. Will keep an eye on it :icon_tup:

all 4 corners of my sun/moon roof tray rusted, I fiberglassed it but later decided to swap it for a mint used one.


if you have sideskirts, check the mounting screws.

^ Good tip. I will check those mounting screws under the side skirts today..

Do any of you guys experiencing rust have cars which have always been garage kept? Mine has, and that is one of the reasons I bought it. I am sitting here chewing my fingernails thinking that I may have hidden rust. I highly doubt I do, but anything is possible.

Very useful thread!

I've found a 2 square millimiters bit of rust where my taillight meets my rear fender. I've lightly sanded it to remove it and put just a bit of paint with a match (yes, with a match).

I've heard rust is cancer. I've sanded it ALL, no rust was remaining. Will it come back? It rusted because a bit of paint was gone when I installed my tail light and it's a great place for water to pool. Now it's painted again.

I work on a ship and I won't see the car back before a while (2-4 months).

Thanks for your help guys!

Thank you guys!

As long as you removed as much of the surface rust as possible, you should be okay.

Having said that, straight paint on top of raw steel is not ideal to keep rust at bay.

A better option would have been to scour the rust off as you have done, and then brush on any of the following things:

rust converter

rust de-oxidizer and sealer

epoxy primer

fish oil

And then a layer of paint over that. Straight body paint or touch up paint will not stop or slow down rust on its own.

*I live in a very wet, rainy/cold coastal area and my car is kept outside 100% of the time- like the rest of my cars. I do not have a garage for it. I have no rust, but I have extensively treated the car to seal all the problem areas*

I've sent my girlfriend to see my car and she told me that 0 rust or semi-rust was there.

BUT, let me tell you that you rock. Your answer is just perfect, couldn't have anything better. Next time I will use one of these products and inspect everywhere you mentionned in the original post.

Thanks to you!

For us USA folks, I use Wurth Wax Cavity, and other Wurth products:
WURTH USA | Automotive Chemicals, Fasteners, Hand Tools & Electrical Supplies | PDF Catalog - Auto
Wurth Wax Cavity Protection Spray - 892082500

:-) neil

Just discovered a hole 3"x 2" in diameter beneath L front peice of the 2 piece 99 factory skirts. WOW!! This was on my visibly rust free FD. I plan to remove the right side front piece also to inspect it. Makes me wonder where else rust is hidden.

Fd3 corrosion
 

Hi guys?I'd just like to add my bit to the corrosion issues,my fd3 had a problem with the drivers side (UK rhd model)sill to floor corroding through,have any of you had this before ?

Yep. I just repaired that area in my car, but on the opposite side. You can check out the fix in my build thread. I believe the car rusts there due to improper jacking.