Is this hole supposed to be there? (W123 under battery tray)

[BenA105]

Hey folks,

I've been interior leak hunting on my '82 W123 wagon and I currently have the battery tray out of the car. I'm cleaning it up and giving it a coat of POR15/Miracle Paint to preserve it. As well as that, I've been trying to see if there's leaks coming into the cabin from underneath. I do get that dreaded wet floor on the passenger side of the car. I also live in Vancouver, BC, so we get a fair amount of rain!

So my question: is this hole a drainage hole, or is this a nicely rounded rust hole? Pic attached:





I'm not convinced it is a rust hole. It's basically perfect. I don't want to fix it if it doesn't need fixing!

Thanks!

[BenA105]

No thoughts?

[optimusprime]

A rust hole,it will let water in to the footwell .Push a wire through it you will find it come out in the footwell .

[Ferdman]

BenA105, it's likely a drain hole to prevent water accumulation in that area. I am unfamiliar with 123 vehicles.

[Stretch]

There is a drain hole around there - I'm pretty sure there is - been some time since I was last poking around my W123 though.

If you remove the plastic covers behind the rear wheel in the arch you might be able to see a better view of what the structure looks like. If there's evidence of a lipped / pressed recess then it is meant to be there (and probably a rubber drain like bung too)...

[Demothen]

I can't really see in the picture, but there is a drain hole with a tube that exits underneath the fender in that general area. If you pour a bit of water there and it drips out onto the tire, that's fine - but if it's into the passenger compartment you have an issue.

[BenA105]

Thanks for the comments everyone - it's appreciated. The hole I found is indeed a drainage hole, which is excellent!

I did a lot of exploring today and came up with some issues.

I began with the hosepipe-down-the-passenger-side-drain scenario first. The rear passenger footwell immediately filled with water, channeling down the plastic wire cover. I didn't spot it initially. Damn stealthy water leak! I had all the carpets removed that side, and also took the lower dash panel off too for extra access (I really must replace my heater blower too - thing is starting to squeal its nads off).

Following this, my wife's hairdryer (ssshhh!!) proved extremely useful to ensure all the flooring was then thoroughly dried. It seems like the protective layer on the floor in the passenger side rear footwell is starting to crack and soften from moisture getting in now, although there's no signs of rust there yet thankfully.

So it seems like there's a leak coming from right in the corner of the bulkhead somewhere. Also, one of the rubber pipes that travels through the bulkhead has a rubber grommet that's all wasted away, so you can see daylight from under the dash. Not a lot of daylight - and the leak clearly wasn't coming from there - but it's not going to help matters, so I'll be re-grommeting (yes, I made up my own word) that!

I then got the car jacked up, wheel off, and removed the plastic wheel arch protector. After I'd removed the garden load of compost that was stuffed inside the wheel arch and at the base of the front wing, I could see a lot of extremely damp metal on the inner arch, with some (not too severe) rust forming on bits of it, and some sealant between panels starting to decompose. Looks like my leak is coming from a gap between panels!

Fortunately, it looks like I've caught the rot in its fairly early stages. It, of course, needs sorting as soon as possible, and luckily it's far from fatal at this point, phew! The car is going into (underground, secure) storage in March for about six months whilst I'm overseas (in the land of non-rusty old Mercedeseses - the Middle East. Parts anyone?!) I think I'm going to stop the rot from making any more progress for now, and then wipe it out when I get back and have more time.

For now, I've made sure the inner arch is damn clean (34 years of mud and crap builds up pretty nice!) and also thoroughly cleaned the plastic inner arch liner. I ran out of daylight today so I'll be continuing tomorrow.

A couple of questions following this adventure:

- Resealing the cracked protective lining on the passenger rear footwell: any recommended products for this?

- Any recommendations for sealant to replace the decomposing sealant on the inner wing too?

Also, here's a few pictures (everyone loves pictures, right? )





Battery tray before


Battery tray after


The dent on the wing has been driving me crazy since I bought the car ten months ago, but there's more important things in life to spend that money on (for now!)




On my shopping list too

[Stretch]

The dent in the wing looks way worse than it is. Go and see a "paintless dent removal" chap (not a "normal" body shop) and I'm sure they'll be able to make it look so so much better. Don't be tempted to buy a new / replacement wing the effort required in replacing and getting it to look correct is immense.

Sealant on the inner wing is probably RTV - silicone and paint isn't such a great match but if you clean out these areas - degrease (!) - and then repaint with something like POR15 then it'll be a pretty good repair for the next few years. If you are going for a beautiful repair, however, you have a whole load more work to do...

...cracked sound proofing on the floor pan usually means rust underneath.

What has probably happened despite the liberal use of your wife's hair dryer is that water has gotten under this sound deadening and has spread itself across the entire floor pan. Capillary action is a bugger!

If I were you I'd hack all of the old sound deadening away from the floor pan and replace with a modern equivalent. These "horse hair" and bitumen type pads are still available from the dealership but they come really stiff and flat and need serious amounts of heat and patience to get them to fit. I don't think it is worth the effort.

[BenA105]

I remember back in the day about ten years ago you could buy sheets of that self-adhesive deadening. Car audio places would be best for that I'd imagine! Thanks for the suggestions on products too.

I did actually lift up all the deadening on the affected area in the rear footwell. It's dirty and damp under there, but fortunately not rusty. Lucky escape! I left a heater blower in the car for an hour to fully dry out the area and next I'll be resealing it all.

So I have found the source of the leak for sure. This morning I spent a while cleaning up the inner arch area with a Dremel, and exploring the full extent of the rust. Underneath some crusty, 35 year old sealant I found this absolute gem:





Fortunately, the hole itself is not too big and there's plenty of decent metal around it. It's a little nasty looking but some chopping and welding then resealing and she'll be as good as new (almost).

With my imminent departure from Canadian shores for a while I'm going to (for now) have to stop the rot in its tracks, clean it all up, and get it welded later on. At least the car will be warm and dry for the time I'm away and I know what exactly needs to be done, instead of constantly drying the rear footwell!