I found the positive terminal was a little loose when inspecting the battery. On closer inspection, the acid ate through the clamp on the positive terminal. A light pull and it broke free.

If it weren't for the massive glob of dielectric grease put on there by the dealer, this would have come loose long before. As usual, the battery post is lead. Duh! But the big surprise was that the clamp was copper based. WTF was Mazda thinking? If you have a copper clamp and a lead terminal, you will have major corrosion and the sacrificial metal will be the copper. This explains why there was so much corrosion.

I went to the dealer and ordered a new terminal. (Hoping Mazda figured out the problem.) I got part number F151-67-TB1 . Thank God, the material looks like zinc coated steel or aluminized steel. I suspect this will hold up better. BTW: don't forget to stop by Home Depot and pick up a new 8mm x 1.25 metric nut. My old one was so corroded that I nearly broke the stud trying to remove it.

The dealer had no knowledge of a TSB on this. Anyone have the same issue?

 

Stock audio or aftermarket?

 

Consider getting an AGM battery when the time comes and you'll never have to worry about battery-instigated corrosion again.

My OEM positive terminal clamp looks like steel -- 2004 build.

 

Check the charging system too.

 

I had a similar problem, the retaining arm that goes over the battery has accumulated a bit of corrosion on it, and I can't figure out where the acid is coming from. The top of the battery is junk free. FYI I have had a charger hooked up to it while it is being stored during the winter.

 

All stock electrical. No goofy ground wires or anything like that.

Judging by the greenish corrosion, I'd say the copper terminal is the leading cause.

 

I've been told that gluing a copper penny to the top of the battery will keep the terminal from corroding. The penny was changed from copper to zinc in the 1982, so look for an older penny.

 

Even back when cable ends were made of lead they'd accumulate blue fuzzy corrosion. There's also no getting rid of copper, since at some point (like the cable end of the clamp) the clamp gets attached to the copper wire leading to the electrical system.

Felt anti-corrosion pads that go under the clamps may do some good. Coating the posts and clamps with vaseline before installing, then smearing vaseline on top after they're on, helps tremendously.

Ken

 

Holy Dead Thread! Sorry to bring it back. Since getting the 350Z, I rarely drive the RX anymore. (It's the wife's DD now.)

Looks like the corrosion issue is much better with the new terminal. Just thought I'd document that for future searchs on this topic.

Assuming people actually do a search.

 

looks like i'm going to mazda tomorrow to get myself the same part. mine did the same thing.

 

so i received the F151-67-TB1 but now don't know how to replace. here is a picture of what the terminal looked like when it snapped:



but i was hoping this part would include the bend and is just the terminal. not sure how i'll get the old off since it's pretty much on there and be able to replace it with the new.

 

Price the dealership and price your local junkyard. I bet the latter is cheaper

 

Cut off old, put on new. Simple as that.

 

I think the retaining arm "corrosion" is actually just the white lettering on the battery top [Interstate] abrating due to vibration. Once wiped off it hasn't returned for me.

 

so find something to cut along the red line i have added below and add then attach the new? sounds easy enough but i haven't done it before so i didn't want to screw something up.

 

If I'm not mistaken, you need to remove the top nut holding the broken piece in place. Then clean very well with a baking soda-water mix to neutralize the acid. Apply vaseline to the new part and install in place of the old part. Coat the assembly with vaseline, and reinstall on the battery. Hope this helps.

 

okay - so finally had enough time to work on this yesterday and it was a pain. luckily the black plastic piece unclips at the bottom so i could remove and work on it outside the engine bay. from there i rinsed several times in baking soda and water and finally was able to (with the help of some vice grips and socket wrench) get the nut off.

after getting the nut off, i tried to push the bolt through but it was too solidly set so i had to get some needle nose pliers to remove the old back piece (would be the bottom not readily shown in the picture) to then remove more corrosion from the back of the bolt and free it. after pulling out the remaining pieces of the old terminal and cleaning again, i was able to attach the new piece, add some vaseline, and reinstall. everything works great now so thanks to all for the help.

i probably won't check this thread again after a few weeks so if someone ends up having this issue and bumps it, feel free to send me a PM and i can walk through more detailed steps if the above didn't make sense.

 

Just checked my battery yesterday, as I typically do when periodically under the hood, and aside from a little dust it was clean. There's no more 'white substance' so again presumably it was just the raised white lettering of the Interstate where it's worn by the hold down rod.

Difficult for me to comprehend how the OP's terminals got to such a condition. That didn't happen over night/week/month ... Preventive inspection and maintenance, or "an ounce of prevention is worth a pound of cure!" Sorry you had to learn the hard way.

 

but how often do people really check every nook and cranny of their car? i know i cleaned my engine bay a couple months ago and even took the battery cover off to clean it and didn't see anything. our positive terminal has a cover on it where i'm assuming that all of that corrosion was happening b/c i didn't see it. and quite honestly, i don't check that closely that often but really wanted a clean engine bay so happened to have taken off my cover.

i check my oil and other fluids but never thought i'd need to take off the battery cover and positive terminal cover to check things. obviously with what i've seen now, i will be keeping an eye on it but i wouldn't expect that to be something everyone does on a regular basis.

 

I bought a 2008 RX-8 in May just back from a three year lease. The car had 17k miles on it and was serviced by the dealer every 5k. The only repair receipt I found was for a new battery, but I didn't think much of it. At 22k I had the car serviced no problems; at 25k the battery is dead and the negative cable and terminal are covered in corrosion. I called the dealer and that say that the corrosion could spread and would cost $400.00 to fix if it could not be cleaned with a service. I contacted Mazda USA to see if they will cover the repair. Has anyone else been able to get Mazda to pay for this recurring problem?

 

corrosion @ battery terminal is nothing new. don't make it sound like it's Mazda's problem. it's actually YOUR problem just like fuel, brake pad, etc.

 

Yep, it is called preventative maintenance..

But hey, my OE 1910 model T never corroded...I will NEVER buy another Mazda EVER AGAIN! (JK)

 

The terminal is not the issue, I have never seen the cable so interwoven with corrosion.

 

The battery was checked ny the dealer at 22k, it goes in every 5k. I think that qualifies as preventative maintenance.

 

Went old school, clean everything with a toothbrush and diet coke; then put on anti-corrosion pads. No problems since.