1986 Carrera Door Sill Bulge

[NeedAJoker]

I am somewhat afraid to even ask after seeing some videos of rusty door sills, but I noticed a bulge under my passenger door sill trim that I either have never paid attention to, or is newish. When I push down, it feels pretty solid, almost like a screw is working its way out, but I don't think there is a screw under there?

Owned for 8 years, has never seen water under my watch beyond maybe a dozen car washes(sad I know). Was previously an Arizona car at least to start its life, and I don't see signs of rust anywhere else.

The door sill trim is in good shape so hate to pop it off unnecessarily and have to deal with the glue, but, I can't just leave it without looking can I? Can I just pry up this back part and take a look or will I likely need to pull it completely off and replace?

Thanks in advance.

[wazzz]

You can just pull it partly. Or fully, it won't hurt it. You can stick it back with special tape.

[NeedAJoker]

Well ****. Am I screwed here or is there a chance this is just surface rust? I scraped off the loose rust and there is no through hole that I can see. I can tap on it with the plastic trim tool and it sounds solid.

There is a hole in the door seal(that is not on the drivers side) right above the rust spot. Could that have caused water from washing the car to just sit there and corrode?

I guess most importantly, what is my next step?

[rokemester]

Sorry to be the bearer of bad tidings but further exploration is required on both sides of your car. This is a well known trouble spot for 911s. Been there and dealt with it on my 87. The body and paintwork forum has many examples of this repair. Requires professional intervention for sure.

Interestingly enough I only had an issue on my passenger side. Hopefully same for you.

[RobFrost]

Looks like it's from the top rather than the bottom. If you enjoy driving it, hit it with some rust converter, paint over blue and glue the trim back on.

Don't go down the rabbit hole unless you're ready for $3,500 per kidney bowl and six months off the road.

Sent from my SM-G988B using Tapatalk

[Glenfield]

If you can, take the rear wheels off and look fwd of the wheels into the back side of the kidney bowls. Poke around with a screwdriver and a flash light to see if that’s where the rust emanated from. If so, it’s a bigger pain.

I had surface rust there last year and got lucky. Was just that, surface rust caused by plastic pulling back and car wash water standing.

[NeedAJoker]

Thanks for the help everybody. Have close to zero knowledge when it comes to rust. I do have a pint of Iris Blue paint, so:



1. Should I try to grind/sand it down gently with a Dremel/hand to remove as much rust as possible? If I can get to metal, that would be a decent indicator it is from top and not bottom?
2. Then hit it with rust converter?
3. Then prime? Then paint.
4. Replace Sill

I did a bit of poking and prodding, tapping around above the oil lines, and everything seems very solid. I did this with my face 5mm from the floor though so might jack it up for a better look. Will update with some pics.

[Coastr]

It looks to my eye that this is rust from water sitting, not coming up from inside the sill.

Your plan sounds good - small wire wheel on dremel, rust converter, prime and paint, stick sill back down. I’d do it with a brush. Follow the instructions on the paint to a tee and take photos of each stage. If you can’t see/ find any in the sills or kidney bowls you’re probably ok or another 5 years from finding it.

[prschmn]

Is it a Targa? Kinda common on them-if the door gaps don't open up a ton when on a lift
clean it up and forget it or spend probably $2K a side to fix it.

[NeedAJoker]

No, it is a Coupe. The hole in the bottom of the door(drain?), aligns perfectly with the hole in the door seal, which sits right on top of the rusty spot so I think it is just pooling there. If I can fix the rust, I will still have this same problem in the future so will just be very cognizant to let that area dry post car wash. Probably should replace the seal.

Hopefully when I get into it today there isn't a through hole where it has been leaking inside, if there is, I will just take it in to be sure we don't have bigger issues.

[Dpmulvan]

Originally Posted by NeedAJoker

Thanks for the help everybody. Have close to zero knowledge when it comes to rust. I do have a pint of Iris Blue paint, so:



1. Should I try to grind/sand it down gently with a Dremel/hand to remove as much rust as possible? If I can get to metal, that would be a decent indicator it is from top and not bottom?
2. Then hit it with rust converter?
3. Then prime? Then paint.
4. Replace Sill

I did a bit of poking and prodding, tapping around above the oil lines, and everything seems very solid. I did this with my face 5mm from the floor though so might jack it up for a better look. Will update with some pics.

Use some 80 grit and sand down to clean metal, hit the nooks and crannies with a sand blaster if you have access to one.If you can’t get every spec of rust hit it with some rust converter ( just the rust) not the clean metal. Then either use a 2k epoxy primer or a etching primer 2coats, then use the paint in your hand.

[NeedAJoker]

Dpmulvan, this helps a lot! Heading out for supplies shortly and I would not have known to get the etching primer. Much appreciated!

[NeedAJoker]

Used a combination of brass brushes and conical sander on the Dremel to get to this point. There are indeed two holes that go through. The larger one on the left is a shallow bubble just a few mm deep, then more hard metal. The pin hole on the right is too small to see through, but does look like it is maybe hollow under there. Hit all the areas you can see in the picture pretty hard with metal screwdriver and no give anywhere. That dark line in the middle is not a hole, it is a ridge that has shadow but is solid.





About 6 inches right of the problem area is a factory hole, and while I can't see down there too great, I do see a lot of blue on the walls and don't see any visible rust.

Jacked up the car using the jack pad for the first time in 5-6 years, and no weird sounds or cracks, car moved up as soon as engaged, no give in the jack point. Checked from below, in passenger rear wheel well, tapped and banged on everything and solid as can be everywhere I thump.





Am I heading to Home Depot to get a borescope to look around inside that factory hole?

[Locker537]

Checkout the "depstech" brand of borescopes on Amazon. Cheap, but good for the money and infrequent use.

My car has the same little problem area on one side. I've been ignoring it.

[NeedAJoker]

I think it will drive me nuts not knowing what is under there so I have to look, but as long as it isn't expansive rot, I will probably ignore it for the time being and keep it dry and an eye on it until a later date. Will see if I can source a cam locally so I can get it done with and off my mind before the weekend.

[GaryR]

I would have that area cut out, inspect the inner rocker, and replace with new metal properly prepped and painted.. 95% of the time rust is like an iceberg, better to deal with it now than later..

[Locker537]

Originally Posted by NeedAJoker

I think it will drive me nuts not knowing what is under there so I have to look, but as long as it isn't expansive rot, I will probably ignore it for the time being and keep it dry and an eye on it until a later date. Will see if I can source a cam locally so I can get it done with and off my mind before the weekend.

Auto parts places usually have the cameras for "free rental with deposit" as well.

[Dpmulvan]

You can buy a good camera for 20 bucks off Amazon that hooks up to your iPad/iPhone with about 10 feet of cable.

[Dpmulvan]

Originally Posted by GaryR

I would have that area cut out, inspect the inner rocker, and replace with new metal properly prepped and painted.. 95% of the time rust is like an iceberg, better to deal with it now than later..

Your right but considering the OP is using a Dremel tool he probably doesn’t have the welder or other tools/ experience to cut and weld in patch panel or drill out spot welds and replace.

[NeedAJoker]

This is absolutely correct, I do not possess any of those tools, skills or knowledge. That said, after spending the last 6 years deferring tasks on my small pile of cars to focus on little humans, I kind of have the itch to get my hands dirty. Admittedly, this is probably not the car or the task to practice on, so after a good look I will likely take it in to my Euro mech.