Rust penetration in wheel well - water leaking interior?

[Cressida]

I have been struggling with water getting into the passenger floor of my 1993 Olds Ciera for several months now. After cleaning out the cowl, beefing up the door seals, having the heater core replaced (it was leaking) and checking the evaporator a/c drain I was still getting water inside! So yesterday I pulled out part of the carpet and was surprised to find that the water is entering from a rusted out area in the wheel well. I was able to confirm the water was coming in here by pouring water down the right windshield area and saw water coming in a rusted area right up under that black material in this first picture.

I was surprised that my screw driver poked through as shown in the second picture. My plan is to take the tire off and hit that rust area with fluid film and wondered what I might then cover it with? For example, put J.B. Weld over the area; and/or spray some rubberized sealant over it, etc? Or, do I need to find a welder or body shop and let them add more material?

The car has 135k miles with a strong 3.3l engine and has been well cared for in the BITOG fashion over the past 20 years. I've never had a body rust hole like this to deal with before so I welcome advice on making the repair. It's not a long term keeper so don't want to over spend, just want to keep it dry and going another two years.

 

[AdmiralYoda]

Since this isn't some classic car in need of a "professional" repair, and you state that you aren't going to have it forever....here is what I would do.

Take off that wheel liner to expose the rotted/rusted out area. Use a scraper to get rid of the undercoating or whatever gunk/paint is on there. If it isn't a big hole and is just a crack...fill it up with some automotive seam sealer.

If the hole is a bit bigger, get a thin piece of aluminum and make it fit over the hole on the inside of the car. Use a bunch of seam sealer to adhere the panel on the inside, making sure 100% of the patch has seam sealer on it. Let it dry and apply some to the outside to smooth it out. Problem solved for a couple years at least.

I think it is too late for Fluid Film, Woolwax, etc.

 

[crashz]

I'm with the Admiral here. And don't Fluid Film first. It will cause the sealer to not adhere to the surrounding metal.

 

[50yr Street Mech]

The Admiral has the correct fix, but I'm lazier than the Admiral. 06' Camry. Took off the wheel, removed the entire plastic wheel well so I could see everything, and to have more access. Chopped out the rust. Wire wheeled what I could to get good metal. Mixed up a couple of batches of Bondo. Cut it all to size before it fully cured. While curing, took apart the other side to look for damage. No damage, just cleaned out the leaves and junk. Put it back together. Came back to the bondo area, hit it with undercoating spray. Done. 6 hrs tops. You say it's not a long term keeper anyway......FOR SALE Oh, you REALLY gotta watch the brake lines and fuel lines on those things. They leak like crazy......

 

[eljefino]

Seam sealer and bondo will fall out. Get some aluminum-- it can be flashing. Or use steel from metal roofing or an old computer case. Stick it on with a couple self-tapping screws, then once the holes are drilled, remove it, put seam sealer, caulk, or RTV on back then reapply over the same holes, put the screws in, put more in to suit your idea of structural integrity. That hole sees a lot of splash so it needs to be repaired pretty tightly.

 

[50yr Street Mech]

He said " it's not a long term keeper", so I gave him a short term solution. I had a 93' Cierra with that 6 cylinder. 4 door / Red. Bought it for $500 bucks with low miles...., and it wasn't sitting on the grass either.... Never had a water issue. BUT....and a BIG BUT....were the rotten brake lines and fuel lines. Joplin gets snow, that means Joplin gets road salt. I'm in NY. The salt shaker capital of the world. Cressida, have a looksy at the condition of the above mentioned lines ( there's a canister fuel filter by the driver rear wheel too, good luck getting that apart. Threaded fittings ). I have never changed so many leaking brake lines, or fuel lines, or fuel return lines in my life, except on that Oldsmobile. I pieced out most of the fuel lines with fuel hose and wire loom for protection. They're still gonna rust because the lines are cheap factory garbage, even if the car never seen salt. Great engine and tranny, that's about it. Lemme know what you find snoopin along those lines. That's why I gave you a " short term solution" Undercoating on that car is almost non-existent.

 

[Cressida]

So far I've never had a problem with the brake or fuel lines. However based on your comments, I'll take a good look at them and maybe spray some rust preventative on them. I already changed out that fuel filter canister a couple of years ago and I don't remember running into anything major in the job.

Thanks for the comments. I'll report back how it goes later.

 

[50yr Street Mech]

Good, glad you haven't had any problems. But yes, get the car up on jack stands as high as you can safely get it. Remove the wheels. The majority of the stuff in question is on the driver side . Get a good look at all those lines. Like I said, GM put the cheapest garbage under that car. Check the gas tank too, and the straps that hold it up. That 93' Cierra gave me PTSD !!! ....Now, every car/truck I own, I examine all the lines, clean them, and spray paint them with " Rustoleum Farm & Implement" paint. It's 10x better than enamel, and can withstand road salt. It's paint, not undercoating, so if you ever need to make a repair, it's not all gummed up with spray undercoating. You need to change that fuel filter YEARLY. The gas tank is steel, and rust inside the tank plugs that filter up in no time. I replaced mine every 6 months. And it was already clogged in 6 months. I couldn't blow air thru it...... A plugged filter will leave you stranded. Already happened to me. Same car. ......It's a shame, GM put such a great engine and tranny in that model, but cheaped out on undercoating. I have an 06' Toyota Camry LE. The brake and fuel lines were dipped in this rubbery solution that hardened up like a thick coat of paint. That's the only car I didn't have to spray the lines. Sorry for the novel I just wrote you ....Please change out that fuel filter before you're sittin on the side of the road like I was, waiting hours for a tow.....

 

[Fifth87]

Since this isn't some classic car in need of a "professional" repair, and you state that you aren't going to have it forever....here is what I would do.

Take off that wheel liner to expose the rotted/rusted out area. Use a scraper to get rid of the undercoating or whatever gunk/paint is on there. If it isn't a big hole and is just a crack...fill it up with some automotive seam sealer.

If the hole is a bit bigger, get a thin piece of aluminum and make it fit over the hole on the inside of the car. Use a bunch of seam sealer to adhere the panel on the inside, making sure 100% of the patch has seam sealer on it. Let it dry and apply some to the outside to smooth it out. Problem solved for a couple years at least.

I think it is too late for Fluid Film, Woolwax, etc.

+1 this. Did the same thing to a '92 Buick Skylark that rotted out in the cowl. Worked well.
A panel bond adhesive may work better on a curved surface such as a wheel well to hold a patch. 3M makes one that is readily available.

 

[John105]

That too happened with my Maxima. A "t" in the rear right wheel well where the power antenna drain and sunroof drains combined to go out the well, rusted away, dumping the water in the well. It was my first lesson in rust repair. Nothing short of cutting it out can fix it. Always comes back.

 

[50yr Street Mech]

It amazes me the different ways water gets inside a car. Neighbor bought a 2024 Toyota Cross, brand new. A month later water laying in the pass side floor pan after a heavy rain. Brought it back to Toyota 3X. " We can't find the source. Checked sunroof, windshield, heater- A/C cowl , pass window, weather strippings, etc " So, I tell him, yeah, there just gonna keep blowing you off until warranty expires. " Maybe you left the pass window cracked open or the sunroof " Toyota say.... I told him just keep bringing it back until warranty expires, then drill some weep holes in the floor pan. Sell it soon after before floor pan rots out....