Hi y'all,

So, I've been putting off looking for a while because I was a little afraid, but today I pulled the battery and the computer to get a look down in the HH. I knew there was *some rust there from last time I saw it a few years ago.

But now it looks a little worse, and there are a couple tiny holes. I knocked around the rest of the metal with a socket wrench handle and the rest of the metal still sounds pretty solid.

So I guess my question is, is there any way to stop this rust before it gets worse and I need to replace the whole area?

Can I use POR 15 so something like that to mitigate this? THANKS!

Click to view attachment

Sand it a bit with a flap disc see how deep it goes

I'd pull the firewall insulation and the rear wall in the interior as well before I decided what to do.

I don't think you have all the damage exposed yet.

I can see where it already went through. What you see is only 20% of what's there.

Not what you want to hear, but if you want to do this right, you need to (at the very minimum) cut a hole big enough to get a scope in there.

Uhg, if I cut a hole to scope it out - and the longs are ok - would I just have to weld a patch over the hole?

Sir Andy is right. Your longs won’t be ok because the water mixed with battery acid goes through the hell hole and then sits in the longs. Some of it washes down and in the rear suspension console and since the drain hole is usually clogged up, it sits there and corrodes it from the tank side out. It’s also why so many 914’s have big rust areas on the rear right side long and lower corner of the firewall. It can also compromise the reinforcement bracket that secures the seat belt mount.
Hope for the best but expect the rust.

I have seen this called the "iceburg rule", the majority is hidden.

I would probably scope it and go from there

Remove the engine lid if still on. You will have to pull that bottom corner, at a minimum, of the pad up. Use a light touch. Clean the work area. Bottom side too. Then assess what has to be replaced. Prep. Weld in replacement. Treat salvageable metal with a product like Mar-Hyde. Paint to finish. What kind of shape is the lower firewall in? This is one of those projects that explodes in to way more than you planned. You’re on your head most of the time.

Move along move along nothing to See here

My two cars looked better than that. Both required extensive welding. You have to cut away all of the rusted metal in order to make a decent patch. Else you are just kidding yourself. If you want to slow the rust while you wait I suggest motor oil mixed with the wax from a toilet ring. I would certainly not use Por15. For a lot of reasons. Your most important reason would be that it will make it considerably harder to fix properly when the time comes. There are horror stories about the framework failing, but you also want some good news. These cars were built quite well originally. It takes a lot of rust to make the frame give way. If when someone gets in the car you have a difference in door gap or roof fitting that is a bad sign though.
Good luck. These cars will give back in driving joy what work goes into them: for me. If you doubt that idea maybe it would be best to look for another.

Pull off the rocker. You may have to drill out some pop rivets, but it is pretty non invasive. Post pictures. I hope weare all wrong!

An awl or ice pick is your friend (or frenemy). You can poke HARD before you start any more disassembly and see how much rot is down there. And if you don't know, there are multiple layers of sheet metal along the top of the "frame" there.

I had a similar situation in that corner, and mine turned out to not be that bad. After opening up the longs inside were very clean, sometimes you get lucky. Keep the faith...

Click to view attachment
Click to view attachment
Click to view attachment
Click to view attachment

If it is a East coast car it needs opened up. It is the worst repair to fix on the car. Once it is fixed, the car will go for a long time. Please save this east coast car.

Matt

Thanks for the advice everyone. It was a California car for 48 years and moved to TN (with me) 2 years ago. I think First I'll pull the rocker and see what I can see. Ill post pictures.

Since this is a pretty common repair, can anyone give me an estimate (range) of what it would cost to fix? Since I'm not a welder.

sand blast POR-15 paint chrome yellow

Ok - took the rockers off.

After my shock of 50 years of dirt falling out - it looks like my Jack support plate is trashed, but, aside from that, the rest looks pretty solid?

Click to view attachment

Click to view attachment

Click to view attachment

My 914 was a CA car, 1975. I had to repair the hell hole and the lower firewall due to a leaking rear window. There was a hole in the engine bar support where it attached to the frame. I pulled the rocker covers, but the were solid. That seems like a lot of rust on the jack supports for a CA car.

It is a commitment for sure when you address this properly to avoid future issues. If you do not want to handle the repair yourself, look for a shop familiar with working on 914 rust repairs so they are not learning on your chassis. Probably easiest to drop the motor/transaxle before you tackle this.

It is rare for the rust to be limited to the surface you are seeing. The good news is once done, your chassis will be way better and you won't have to think about it again. If you repair it, be sure to take photos of the entire process. if you ever sell the car, having this area repaired will alleviate concerns by a potential buyer and increase value.

Looks more solid than others, and less than some.

If it were mine, I'd cut /grind most of the lower half of the jack plate off (in red), remove all of the visible rust with a wire wheel, and see what was left over. I'd also want a look inside the long, so I'd either cut a piece out (in yellow) and then look inside- especially since I can already see from the pictures that it's not solid there. After cutting away the lower half of the jack plate and grinding off all of the visible rust, the yellow piece to cut out might need be bigger, depending what shape the metal is in.

Click to view attachment

Very similar to a repair I did on my car (my car's engine shelf was solid- no rust, no holes. This was all due to crud trapped by the rocker panel). Pictures show the 2 layers of metal. Final picture is it all buttoned up with both bad layers replaced. I didn't bother replacing the jack plate because the upper part was fine, and replacing the whole thing may have necessitated cutting into the side panel and I don't ever use the side receivers to jack the car up.

Click to view attachment

Sorry to say that, but you have a lot more rust hiding there. if you thoroughly investigate, you will find a lot more… All depends how deep a restoration you want to undertake.

And for your upper view, no this is not a case of sand bast, Por-15, and paint over as mentioned above.

You can see the rust hole. If this is perforated, the rust is spread a lot farther all around it. The long construction is doubled layered in that area, perfect to trap moisture.

Again, sorry for your finding but not atypical on many 914s even nice looking ones. Most of them have rust, depends what is your tolerance to it.

Good luck, plenty of documented ressources here!

Again, get the ice pick out and stop just looking.

And check both the inner and outer rear suspension consoles.

Above all, don't get discouraged. many of our 50 +/- machines have seen a hard life and getting them back in shape is not too bad for the payoff.

Thanks for all the advice. It's not an adventure I was planning on undertaking this year, but, as you know - never a dull moment with these cars.

Yeah. Good luck. If you were closer I would be happy to help. The secret that no one has yet mentioned: buy two. Yep, work on one while happily driving the other car. I am here to tell you that it works. My ‘76 restoration has taken more than three years, but the six conversion keeps me happy. When I was welding the conversion body, the ‘76 kept me happy. Then of course it comes to buying property to use for car storage. Genius of the whole thing is that I am still married. Good luck!

Lucky guy, must have gotten an angel

Very Lucky! ...and that's why I'm restoring my LE in the backyard! Not ideal but still happily married.

Hello CoronaMike,

Saw that you're in Maryville. I'm in Farragut. Be glad to help of you ever need something.

Regarding your rust, I would just wire brush it, seal the pinholes and treat it with some rust neutralizer and continue to enjoy the car. The rust isn't too bad. I wouldn't be concerned about the integrity. To replace all that nicely is somewhat involved. Document it well if you decide to repair so the next potential owners can see the condition prior which isn't that serious. Don't use those jack points! Use the underbody locations. I'll keep an eye out for ya. My 914 is still in South Carolina.

I agree. Put a little preventative on there and enjoy it. Keep it out of the rain and salt but enjoy the car. The repair will be exactly as involved today as it would be after it is much worse than that.