and you think gas is bad after 5-10 years...try 40 like what was in the tank of my 49 Lincoln 4 door before I hacked the tank out of it, its horrendous.

 

Old rotting interior pieces, gear oil... what really stinks the most is hearing a loud thump and then the truck veers hard to the left...

 

the stuff under the rubber floor mat of the old 85 4x4 farm truck I got. had to replace metal floor boards to get that out peeewwww gag barf

 

When you get the call your friend smashed your baby (03 F-350 6.0L PSD) into a tree while he was drunk, now that stinks.

other than that used gear oil for sure

 

Old brake fluid

 

While we're on the subjet of old stuff, how about old people?

 

the baddest car small i can think of is when people letter their car get trashed with old food and who know what...and then it come to my work to get some body work done and we bake the paint on the car ...some cars smell so bad u have to hang out the window to drive them outta the spary booth so u can breath

 

The worst smell by far is the motorcraft friction modifier that you put in the rear end, dont get it on your stuff- it wont come out and people will just look at you funny...

 

I've worked at a McDonalds for 4 years now, the smell of it makes me cringe now....

Car wise I'd have to agree with the guy who said crap under the floormats... I had a hydraulic jack leak behind my seat once and it took about a month before I could breathe without the windows open...

The smell of antifreeze is always a pleasant one though!!!

 

My rommate hit a vulture w/his mustang and it threw up all over his car. It smelled horrible for the next few days as we were finding animal parts everywhere in the engine compartment Thankfully it really didnt have time to ferment

 

x2 on the friction modifier,
once had a truck come into the shop, tranny gave out making a trash run, sat out in the sun for a few days before comin to the shop, man it was rank, parked it out back and had the new guy drop the tranny out in the back lot and re install the rebuilt one as well, that was a nasty smelling rig.

x2 on the gear lube as well! specially burnt gear lube

 

dead people...end of story.
my buddy worked for tri-gard. (a vault company) and they broke something and i brought out my welder and tools. And they were exhuming someone....They broke the vault...I sneezed like a month later and the smell came back...ehhh

 

truck bed full of horse ****(especially the one summer day when it sat in the bed over night) and gear oil i just changed mine yesterday and the smell still makes me want to gag!

 

gear lube or main cap bearing oil. both about the same to me.
non truck related.
my dad had a cow that wouldnt drop a calf, so he called the vet. found out the calf died in the cow and sat in there for a day or so.
and when i walked in there to see wat was going on my dad stuck his hand in my face and said smell. so i did. how i did not throw up right there and then i will never know. then i got a nice downwind smell of it.
MY GOD i will never forget that. i hope noone ever EVER has to smell that.
Mitch

 

Cow is much worse. I live on a horse farm. We fill a dump trailer load of horse crap all week long. The trailer has an enclosed box, so it gets a little rank in there in the summer.