Fatal rust?

Noticed today that my car is getting really rusty in really sketchy spots. The passenger side inner fender where the motor mount goes is about to rust through, my rear pass frame rail is gone all the way to the trailing arms (sway bars, whatever the hell you wanna call them lol) about a 6in section is gone on the bottom of the frame and my rear floorboards are super soft..Are there ways to save these spots I’ve mentioned? Oddly enough the strut towers are fine?
 

pcb

The Diagram Dude
:
2002 MP5
The only thing that you can really do is get metal welded in but that is expensive and would probably cost more than the car is worth. You could put a layer of fiberglass over the floorboards but the structural stuff needs the strength of new steel.

Your car is becoming unsafe and a big pothole might rip the rear end off the car.

My driver's side floorboards were rusting through so I put fiberglass over it to strengthen it and seal it up.


 
I’ve got angle iron for the rear frame rail,just haven’t measured and cut it yet,it looks like it’ll work. Good thing I’m decent with a welder and we have a ton of random metal laying around from building derby cars lol. The rear tire doesn’t concern me as much as the front does,atleast the bolts haven’t started to pull through yet. im supposed to be going to check out another P5 Friday,it knocks so if I end up with it I’ll just swap engines and part out what’s left of the one I have now
 

pcb

The Diagram Dude
:
2002 MP5
If you can weld then you're in good shape.
It's just a matter of your time and effort or if that other P5 is in good shape then an engine swap would be perfect.

I've got a little 120 volt Arc welder but I completely suck at it. All I do is burn holes. Lol

I punched through my trailing arm connection with my t-stands a few years ago.
I had a piece of metal welded in so that my trailing arm wouldn't break off.
It cost me about $150.

 
Last edited:

Natey

Moderator
Contributor
Patron
MY MSP was from California and never saw snow. I live a block from the pounding surf though, so the salt around here is airborne.

When I sold it, it had under 75K miles on it, had never been wrecked or even tracked and was 100% stock. (Find a sub- 80K mile MSP that's never been modded).
I had a buyer for it for 4500 bucks, but upon closer inspection, all four doors were so rusted behind those black plastic coated B Pillars, that structurally, it was dangerous. I couldn't just sell it as is.
I told my buyer about it and sold him the car for 2 grand. My Protege 5 had the same problem. Behind those black door pillars was a rusty nightmare.

Moral: 3rd gen Proteges are among my favorite cars ever, but they're not exactly made of Japanese Samurai Sword material.
 

pcb

The Diagram Dude
:
2002 MP5
I remember reading here on the forum years ago that all P5's were 100% built in Japan and they have really strict environmental laws where they are required to use 100% recycled metal.
Apparently, it's really hard to get all the impurities out of the metal during the smelting process which leads to the metal rusting exceptionally bad.

When I bought my car about 11 years ago, I took it in to have it undercoated the day I bought it.

They drilled holes in the pillars and all around to spray inside the cavities.
The car was pretty rusty when I got it but if I wouldn't have had it sprayed every year, my car would have rotted away more than 5 years ago.





 

pcb

The Diagram Dude
:
2002 MP5
PS...

I found a hidden rusted spot on my front strut towers.
It's up in behind the front wheel well area.





Both my front sides are rusted out then dirt, crap, and saltwater gets flung up inside that area and rot things out really bad.
I keep spraying down the area with undercoating.
There's a plastic plug that I remove to spray down that area.





It's supposed to be a sealed cavity but mine aren't sealed anymore.

Interestingly, my parts car isn't rusted out at those spots but it's way worse for rust everywhere else.
 
If you can weld then you're in good shape.
It's just a matter of your time and effort or if that other P5 is in good shape then an engine swap would be perfect.

I've got a little 120 volt Arc welder but I completely suck at it. All I do is burn holes. Lol

I punched through my trailing arm connection with my t-stands a few years ago.
I had a piece of metal welded in so that my trailing arm wouldn't break off.
It cost me about $150.

Yeah I’m definitely gonna check out the other P5 before I “waste” good angle iron,that’s how we make our core supports,and frame rails,and possibly the c-notches for my truck lol. Hell I’d love to have an arc welder,we got a little Hobart mig and I can never set my feed at the right speed. You should just start collecting random pieces of scrap metal to practice welding together,I was lucky enough to go to a vocational school with welders and unlimited metal to test on.
Oh and on the rusty areas under your hood,next time you put undercoating on it,wipe it down with some ATF first. For some reason it’ll drastically slow the rust down and it makes the metal last a little longer. Old derby trick,we do it with our driveshafts all the time. I also did it to the subframe on a cavalier I had that was rotting out bad. I figured the subframe would’ve broke but it didn’t,the slave cylinder went out before the frame went lol. Not 100% sure how it’ll work with the Japanese metal but it works wonders on good metal
 
MY MSP was from California and never saw snow. I live a block from the pounding surf though, so the salt around here is airborne.

When I sold it, it had under 75K miles on it, had never been wrecked or even tracked and was 100% stock. (Find a sub- 80K mile MSP that's never been modded).
I had a buyer for it for 4500 bucks, but upon closer inspection, all four doors were so rusted behind those black plastic coated B Pillars, that structurally, it was dangerous. I couldn't just sell it as is.
I told my buyer about it and sold him the car for 2 grand. My Protege 5 had the same problem. Behind those black door pillars was a rusty nightmare.

Moral: 3rd gen Proteges are among my favorite cars ever, but they're not exactly made of Japanese Samurai Sword material.
I’m pretty sure my doors are rusting out like that,my car sat in the weeds for 3 years and all that moisture getting in everywhere definitely took its toll.
Ya know now that you mention it,I’ve never seen a MSP with less than 140k around here. Almost all of them have rust too,found one that needs frame patching and axles for 900,hard telling what else it needs being so ate up with rust
 

pcb

The Diagram Dude
:
2002 MP5
I've never tried ATF but I did spray down the underside of my 626 with 10W30 and in a couple of months it looked like it was never sprayed and the oil dissolved all my rubber boots on the cables and such.

The undercoating spray oil is synthetic so it doesn't dissolve rubber, and it's nice and goopy. It still creeps and spreads but it stays there and doesn't wash off.

This is what I use. I think it's only available in Canada.

Fluid Film is great too but it is quite expensive (and may dissolve rubber too?)


 
I've never tried ATF but I did spray down the underside of my 626 with 10W30 and in a couple of months it looked like it was never sprayed and the oil dissolved all my rubber boots on the cables and such.

The undercoating spray oil is synthetic so it doesn't dissolve rubber, and it's nice and goopy. It still creeps and spreads but it stays there and doesn't wash off.

This is what I use. I think it's only available in Canada.

Fluid Film is great too but it is quite expensive (and may dissolve rubber too?)


I didn’t even think about the rubber components lol ATF would probably chew right through it too. I know one decent coat of it though and you don’t have to do it again.
yeah I’ve never heard of that stuff before,last thing I undercoated I just got a few cans of sprayable rhino liner,a bunch of painters tape and cardboard then went to town. It was on my old Tahoe,kept my rear rockers in one piece until I scrapped it lol even when they were tearing it apart with the excavator the rhino liner didn’t wanna come off
 

pcb

The Diagram Dude
:
2002 MP5
...,last thing I undercoated I just got a few cans of sprayable rhino liner, a bunch of painters tape and cardboard then went to town...
The problem with truck bed liner or rubberized asphalt undergoing is that you pretty much need to apply it to clean rust-free metal.
If you apply it on rusty metal, it seals in the rust and moisture and the rust keeps creeping underneath.
The coating can crack and let moisture creep in then the rust just carries on.


I've had about 5 cars in my life and lost all of them to rust.
I wish I could have afforded a new car that I could have protected properly from the start.


Another awesome redneck rust inhibitor is a 50/50 mix of grease and roofing tar.
You heat it up on the stove to blend it and thin it out then spread it on with a paintbrush.
It hardens up a bit when it cools so it's not so messy but it stays oily/greasy so that the metal is always coated and protected.



That's what I covered my floorboard fix with.

 
The problem with truck bed liner or rubberized asphalt undergoing is that you pretty much need to apply it to clean rust-free metal.
If you apply it on rusty metal, it seals in the rust and moisture and the rust keeps creeping underneath.
The coating can crack and let moisture creep in then the rust just carries on.


I've had about 5 cars in my life and lost all of them to rust.
I wish I could have afforded a new car that I could have protected properly from the start.


Another awesome redneck rust inhibitor is a 50/50 mix of grease and roofing tar.
You heat it up on the stove to blend it and thin it out then spread it on with a paintbrush.
It hardens up a bit when it cools so it's not so messy but it stays oily/greasy so that the metal is always coated and protected.



That's what I covered my floorboard fix with.

Before I undercoat I always spray some rust neutralizer on everything to keep it from spreading,I too have lost far too many vehicles to rust. I had a 95 s10 ss for years,drove it til the frame broke then wedged some cut logs in the frame,ratchet strapped it and drove it for another year🤣 all my Honda’s but one got destroyed by the copious amounts of salt Ohio puts on the roads in the winter.

that’s pretty nifty though,I’m gonna have to give that a try. It’s gotta be cheaper than 3 cans of bedliner
 

pcb

The Diagram Dude
:
2002 MP5
I can confirm that FluidFilm cause rubber deterioration.
Apparently, FluidFilm has sheep lanoline in it which makes it expensive.

I remember buying a gallon of the stuff for about $80 at the time and coated my Tracker.
I pulled all the paneling off the truck and spread it everywhere with a paintbrush.

It lasted for the entire 8-9 years I had the truck.
It just stays there all goopy and oily and keeps protecting everything.
 

pcb

The Diagram Dude
:
2002 MP5
... that’s pretty nifty though,I’m gonna have to give that a try. It’s gotta be cheaper than 3 cans of bedliner

The roofing tar cost about $11a gallon and the grease was cheap too.
The best part is how it stays a bit oily so the metal is always coated and sealed.

I've had problems with rust converter, it just didn't seem to last.

I'm sure it wouldn't work for something like this. Lol




An oily coating will stop the rust but you can't paint it. Lol

A link to my battle with rust...

 
Top