Panelhead

My car had an odor when it arrived. Plus a lot of air fresheners. When inspecting the spare, the smell was terrible. With the truck floor closed not too bad.
Pulled the spare and found the inside of the wheel was coated in some nasty dried black material. Organic material. Thought maybe this wheel had be used for daily visits out to slop the hogs.
Scrubbed real well, got most of it off and put tire back. Smell was gone. After a month it got smelling again. Used Clorox, let sit, used detergent, and then Clorox again. After a month or two smell returned. Gave it another good bleaching and black crap wiped off. But not is smelling again.
I am starting to think this is some anerobic bacterium of something. The smell is putrid and seems be be in the metal. The wheel is a factory 19 inch steel/chrome. The stuff is not on the chrome. On the steel it is much reduced, but does not come off completely.

aTOMic

My first thought is "flood car". Do you know its history? Did it come from a state where floods occur and/or where they have to report it on the title?

In any case, I would get a tub or that Dri-Zall or whatever it's called, (WalMart has it) and some strong double-stick mounting tape and put it into the spare tire well. I'd also put the tire in a black trash bag and leave it in the sun a couple days to kill any bacteria.

I've also heard of people removing odors from cars by dumping a bag of charcoal briquets (I'd crush them somewhat to increase surface area).

-Tom

Fez2013

I would remove all the floor panels just to dig deeper and let those "air" out as well.

MP4.2+6.0

Look at the trunk upholstery more closely. When you open the side panels for example (for the battery on right and electronics on left), does it smell in there? What about the basic floor panel, etc.?

Also, is it inside the car at all? Did you pull back seat lower cushion and look under? The smell can just come forward from the flow through ventilation set up (it goes through the rear deck and ultimately exits behind the bumper cover and below the tail lights at some flimsy louvered vents), but I would check and see if it is also in the car.

As far as purging it, variously I have used animal odor type removers and also simply a multi pound bag of Baking Soda I literally sprinkled and worked into the upholstery and floorboards and such and let it sit for days, finally vacuuming it out with a shop vac after I also had everything thoroughly dry before I sprinkled on the baking soda. Happened over the years and vehicles with various trunk gasket leaks and one time with a van where a floor plug came out and then lots of water got in the far back when we put a towed boat in the water one day.

Panelhead

The car did come from NYC, and there was flooding in the area. The smell is only strong when lifting the floor of the truck. And the smell of the spare almost made my throw up. The odor came from the backside of the spare wheel. The black organic material looked like what we call "gumbo" on the gulf coast. Very heavy clay soil with a lot of organic material mixed in.
The wheel does not match the four onn the car, it is the 12 triangular blades and definately steel and chrome -plated. There is not on the chrome.
I really wondered if the previous owner was a pig farmer. He said he replaced the wheels. There is only a little salt corrosion on the underneath. No pig manure.
I will give the wheel another good bleaching, the tub a good scrub, and will set the wheel in the backyard in a black trash bag to bake for a day or two. There is none of this on the really nice Falken tire. It looks new. I do not know who would have mounted with the mystery black on the back of the wheel. It was a 1/2" thick in places.

powderlvr

When I bought my car I noticed a strange odor in the trunk as well. It smelled like livestock or a feedlot, but there was nothing amiss in there. Strange. Mine was definitely not a flood car as I've talked with the previous owner.

-JT

Panelhead

Mine was covered up, or attempted too. When it rolled off the car hauler, the first thing I noticed was all the aitfreshners. Seems like there were four I threw out immediately, and two I found under the front seats later. About a month ago, a dog run in front of and when I locked it down to keep from hitting, and a really big air freshner rolled out from the under the passenger seat. So maybe a total of seven, all different brands and flavors.
The odor is much better, but can still smell lifting the floor in the truck. None in the battery box, the other side has a sub installed.
If this last "bleaching" does not get rid of it, another 19" wheel is in my future. Maybe one that matches the wheels on the car.
I think this odor is why the car was sold. The seller had several interested local buyers and all the deals fell through. I can see why.
The spare being the problem may not have been noticed.

Mister Bally

Maybe the smell has something to do with clogged sunroof drains. If it is indeed just the spare wheel &tire, why not just put it in a large plasticgarbage bag and securly tape shut? Make sure it is large enough to fit in the tub without tearing. You will have to poke a hole for the tire hold-a-matic but you can always put a puece of packing or duct tape to minimize any hole and air leak.

aTOMic

How would they even balance it? I'll answer my own question be saying some tire techs just don't give a crap. They did mine at Discount Tire at Hendersonville, TN and did no cleaning/ wiping of any kind. All four looked dirtier when I picked up the car than when I dropped it off. All four require periodic airing up ( ~3 PSI/two weeks, yes I am accounting for temperature). Luckily, one of my hobbies is tire-pressure checking (do it every week or two max). Also they did not do the TPMS maintenance that the guy talked me into. (I walked back after the tech did the first one and asked why he didn't do it, you can see the work area from the waiting room).
I called the next day and they refunded my $ for the TPMS service plus $100 but they lost my business.
/Rant off
I agree with MrBally on encapsulating the spare; and you could pour some silica gel dessicant or charcoal into the bag around the tire after it's in the well, then seal the bag.