Battery Tray in OK shape?

[eforty6_m3]

While swapping in a new Champion H5 battery over the weekend, I got a real good look at my battery tray. Should I be at all concerned with the current look of this area, or is this par for the course? Wondering if I should look into any sort of rust treatment/prevention or leave it, as is?

Also, unsure what my options are with that hole. Is this hole a result of doing what post #15 from this thread says? And if so, does that mean I can plug that up with the plug also referenced in post #15 (#41007140847)?

Thanks in advance!

[Tbonem3]

I just went through this area. I would add the plug or make your own out of silicone or something.

Have you cleaned the area up yet?

[elbert]

I had something similar but not nearly as bad.
A track buddy had to replace sheetmetal in his car due to the severity so you should definitely try to fix it.

I removed the tray, sanded the rust, and sprayed it with paint. Probably could have used a perfect color matching paint, but I wanted to get it fixed asap.
Bought a new tray and the five (?) nuts that hold it down.

[Nick_P]

I would definitely clean all that rust off, otherwise it will probably spread like cancer

[eacmen]

I had something similar but not nearly as bad.
A track buddy had to replace sheetmetal in his car due to the severity so you should definitely try to fix it.

I removed the tray, sanded the rust, and sprayed it with paint. Probably could have used a perfect color matching paint, but I wanted to get it fixed asap.
Bought a new tray and the five (?) nuts that hold it down.

I did the same thing. Wire wheel and then some spray paint meant to inhibit rust. Took the time and painted the bracket itself as well.

For The hole I would get one of those plastic push rivets for plastic trim, combined with some RTV to seal it up.

[ejendow]

what causes rust in this area?

[eacmen]

what causes rust in this area?

Acid vapor or straight up acid spills.

[antknee]

This was a big prob with e30s. On all 5-6 e30s I’ve owned this area was notorious for rusting (battery acid and just moisture in that area from trunk and/or taillight seals going bad. It would eventually create a hole in that area

my advice, take all those brackets out of the way clean and assess how bad it really is. I would take a wire brush to the rust areas, clean away, use Por-15 (goes on thick with a paint brush) and spray with etched primer after. You want to take care of that sooner than later

[Ianb]

Looks like most of the corrosion is the bolt in tray part, the main car part looks to be fairly good, imagine alot of it is just staining/dirt and will look a load better after a good scrub.

[zeta4]

I seem to remember that this kind of corrosion in the battery tray can be caused by a leaking tail light gasket. Might be wrong but worth checking.

[White_335i]

I had a similar issue with my car. Water from the tail light rubber seal leaks in to it. Check the seal. I replaced the black tray with a new one and under the tray, I used Drexel to sand the rust and put a layer of POR15.

[Altaran]

Mine looked similar. I cleaned it, grinded the rest off (the corners are sometimes hard to reach) and then treated it 3 times with Fertan.

Will add some paint soon to finish it off, but I need to add those two little covers back on. The original ones were bad so I took them out.

[eforty6_m3]

I just went through this area. I would add the plug or make your own out of silicone or something.

Have you cleaned the area up yet?

Not yet. I'm trying to do some research to figure out the best approach to cleaning this up and preventing any future corrosion from appearing. Once I figure out my best course of action, I'll remove the battery and replace the battery tray with a new one from FCP.

This was a big prob with e30s. On all 5-6 e30s I’ve owned this area was notorious for rusting (battery acid and just moisture in that area from trunk and/or taillight seals going bad. It would eventually create a hole in that area

my advice, take all those brackets out of the way clean and assess how bad it really is. I would take a wire brush to the rust areas, clean away, use Por-15 (goes on thick with a paint brush) and spray with etched primer after. You want to take care of that sooner than later

Yep, had similar issue with my 2 E30's, as well.

Thanks for the suggestion! Did you end up painting over the primer, or did you just leave the battery compartment primed permanently?

Looks like most of the corrosion is the bolt in tray part, the main car part looks to be fairly good, imagine alot of it is just staining/dirt and will look a load better after a good scrub.

Agreed! The battery tray (black, bolt-in piece) seems to be in the worst shape, so I'll replace that. I need to get in some elbow grease time and see what that area looks like after a thorough cleaning. Thanks!

I seem to remember that this kind of corrosion in the battery tray can be caused by a leaking tail light gasket. Might be wrong but worth checking.

Will do, thanks!

I had a similar issue with my car. Water from the tail light rubber seal leaks in to it. Check the seal. I replaced the black tray with a new one and under the tray, I used Drexel to sand the rust and put a layer of POR15.

I assume you meant Dremel here? Mainly because I googled Drexel and it wanted to correct to Dremel, ha!

I've now seen two recommendations for POR15. Looks like that will probably be the direction I go in.

Mine looked similar. I cleaned it, grinded the rest off (the corners are sometimes hard to reach) and then treated it 3 times with Fertan.

Will add some paint soon to finish it off, but I need to add those two little covers back on. The original ones were bad so I took them out.

[antknee]

Yep, had similar issue with my 2 E30's, as well.

Thanks for the suggestion! Did you end up painting over the primer, or did you just leave the battery compartment primed permanently?

With my E30, i left tray area inside just primer color (greenish primer).

I have a Silver Grey E46, and i think the color down there is like a greyish primer if i'm not mistaken?

[eforty6_m3]

With my E30, i left tray area inside just primer color (greenish primer).

I have a Silver Grey E46, and i think the color down there is like a greyish primer if i'm not mistaken?

Correct...gray primer.

Here is how things currently look after removing the black tray, vacuuming out the area and cleaning up the rest with All-Purpose Cleaner and some towels:

















Wondering if I should I leave it, as is. Is it overkill to use some wire brushes to get rid of the remaining rust and perhaps treat the area and primer it? Thoughts?