sided00r

Ok, all I find searching for bad smell toyota truck is 'rotten egg', I'm from this century, I have no clue what a rotten egg smells like.

But, my truck, and I'm noticing this is really only apparent in 4wd, and ya, driving more slow, stinks like propane. Really bad. Get back on paved highway, don't really smell it anymore, just the sour remnant in the rug. First time I smelled it up the backroad I had passed somebody and was sure he was burning propane tanks there on the side of the road. Few miles later I realized it was coming from my truck. I'm pretty sure now a few weeks later that it only really happens in 4wd.

Ideas what to look at/sniff closely? Tire shop didn't see any exhaust holes when they had her hoisted.

creswellhick

i know newer toys have that problem its the cat at least it is in my aunts car

sided00r

Forgot, it's '94. Does the catalytic work harder in 4wd or something? Do rotten eggs smell similar to propane?

sided00r

I installed the new cat. It still smells. Sour propane mixed with fuel. Especially prominent as soon as I put it in 4wd. Smell almost unnoticeable IF I close the window, rear slider window doesn't seem to suck it in like the driver's window does. I got out today after a run and sniffed everything, looked for signs of fresh drippings anywhere, can't locate the source of this stink. It's bad. Cat smells fine compared too, so does the tailpipe. Sniffed the upper area under the hood, can't find anything.

Last week I got under someone's Tacoma to look at something, and smelled the same smell that I get in my cab, only faint.

So ya i just put in the brand new Magnaflow. I don't know where to start, there don't seem to be any clues to this?? I ran before with a household CO detector plugged in and it never beeped...

??? blech!!

rworegon

The 'rotten egg' smell is similiar to the smell of water that comes from a well or a hot spring with a high sulfur content. The additive they put into the odorless propane to give propane its distinct smell, methyl mercaptan, has sulfur in it. So, the rotten egg smell may also smell like propane thanks to the sulfur.

Propane [with the additive] smells like rotten eggs, a skunk's spray, or a dead animal. {borrowed from a propane website}

cubuff4runner

I found it depends on where you get gas. There used to be certain gas stations / fuel mixtures that would cause my cat to put off a horrible odor. Others would have no smell.

xxxtreme22r

Bad cat, or running extremely rich under load. Do you have a check engine light on?
My new cat smelled for while (about a month worth of driving) after I put it on. It's been fine since then.

MudHippy

Me thinks him maybe smelling a gear oil leak(or just the ordinary ventilation of the odors of it coming from where it's housed). Might be coming up through the t-case shifter boot or the breather there.

You do know what gear oil smells like right? You say you smelled it getting into someone else's truck. Did it have gear oil in the transmission/transfer case too. I know mine does, and it occasionally can be smelled inside the vehicle. Doesn't bother me that much, maybe that's because I know what I'm smelling though?

Propane is odorless BTW. So technically you can't smell it. You can however smell the odorants they add to it for leak detection purposes.

creswellhick

i was just going to say old gear oil smells pretty rotten but he beat me to it

sixstringslut

Amen to that, I recently changed speedo gear in my T100. It ran down my arm into my coat before I could move my arm. That was two weeks ago and still smells pretty ripe, almost like dead mouse.

sided00r

I think I read somewhere on here gear oil smells like beer nuts and vomit? No, I don't know. But it's heavy the moment i engage 4wd. Like I said, the cat is brand new Magnaflow, and I can see through the old one too, it was never clogged. The smell is the same. I am idling high right now, but I think that's besides the point, different matter. We popped the cork on the transfer case before and the oil looked ok, i didn't sniff it; i will tomorrow, i have a seal for the rear output, and a bunch of leaky spots i'll trace come spring. I also have the black ooze coming out of the clutch release fork boot. Valve cover gasket was done, it's a rebuild and had a new clutch put in one or two years ago.

I have sniffed both cats, i'm sniffing the old one right now, it just smells like metal. They don't possess the smell that i'm smelling. I've lit matches, it isn't exactly sulfur, but in the same family, same strength but more pungent, cabbagey, gross.

I would like to try different gas, but dunno the canadian recipes, saw a page on sulfur content in diesels but that won't help me. But if it really was just the cat, then wouldn't it always smell anyways. What gets churned around more as soon as you engage 4wd?? What else can you put in a transfer case besides gear oil?

I'm also a girl with no mechanical experience and don't want to wreck the truck. I ran it by a toyota guy and he smelled it right away in 4wd but shrugged his shoulders. Heater on or off makes no difference. I have limited funds but will hack my way through whatever i have to do.

But it seems like i have to somehow strap myself somewhere under the truck while someone else drives it, sniffing stuff or watching for drips.

rworegon

Is your front differential vent kicking out gear oil when you engage the 4wd? The vent tube is typically up on the inside of the fender well and gear oil definately has the rotten egg sulfur smell.

bmcghie

2x on something being up with your front differential. If you can't make it smell in 2wd... Seems likely the cause is in the OTHER 2 wheels when they are driven. IE, front diff.

Look for stains on the front diff cover, check the vent hole on the side/top is clear... and at minimum check the fluid level. I believe you need a 24mm socket? FSM will say. I would almost bet somebody overfilled it. Take out the top bolt on the housing, and fluid should seep out a tiny bit (Gear oil should be level with the bottom of the bolt hole).

Good luck, keep us posted.

sided00r

Well i took out the side bolt, that's as far as i got today because i got havin too much fun finding snowbanks to warm things up in. Had to peel off a quarter inch of oil and grime to find the front diff, oil inside just trickled a little, it's translucent grey, and i concur it smells like very mild mild beer nuts and vomit, mild though, nothing like the heavy propane bbq wafts i get. There looks like fresh oil coming down from the engine block but i wiped it all and will look later. Like i said that's as far as i got today, sudsing my little oil pan skid plate that was in the way and have to look up torque on that relief screw. The little chimney-vent thing on top of the front diff, that doesn't go anywhere? Nothing supposed to be attached to it? I don't see any signs of anything coming out of it either way...I dunno, whole assembly there looks in good shape. Not that hot either, wonder if i do have oil leaking, and it is synthetic according to service records, maybe it leaves a bad taste somewhere. Don't see anything dripping straight onto exhaust anywhere.

And I found these now but never heard anything toyota related:
GM gear oil smell - add cabin filter
http://www.acadiaforum.net/forum/ind...?topic=8063.20
Chevy Traverse
http://chevytraverseforum.com/index....-like-propane/
"Removed drive shaft, exhaust pipe, skid plate, right front axle shaft, rear engine mount and bracket, and transfer case (I think this is the middle transfer case). Replaced transfer case vent, re-installed transfer case, routed vent tube to fuel filler cap and secured. Re-assembled all else. Topped up transmission and transfer case fluids. " owner says propane smell pretty much gones

And I'm filling up at the Shell this week, and sometimes i think i smell it in 2wd but it's faint and rare and if it does come it's not anthing prominent like the moment it goes in H4. It's normally a huge relief to pop it in H2, smell go away. Odor lingers in the cab for some time, but i can find no trace of the smell anywhere else.

xxxtreme22r

If you have grey fluid inside the front diff, drain it and refill with new 80-90 immediately. You have water in it.

And that thingy on the top of the diff is called a breather. It should have at least a plastic cap on it with a little rubber disk between the cap and fitting. If not, that explains both the smell and the water in the diff.

Breather should look something similar to this:

sided00r

Ok, i do have that cap but didn't want to wreck the crimp to look for a rubber disk. I changed the front diff yesterday, sure glad I did, traded out ick black charcoal for honey!...so I suppose all my oils will be looking like that. I will do the rear the same, but it looks like the Redline stuff for the tranny will cost me a few bucks and that will have to wait a week or two. I read on here if I'm concerned about seals leaking and cross contamination then I could put the same Redline in the transfer. I know I have seals leaking but I think I will be flushing these all again in a few months - so IS IT a big concern if the oils mix through leaky seals? The other stuff is Castrol Hypoid sp? something 80W90. Mainly, I have not driven a lot since yesterday but my initial perception is that yes I still have the propane smell. So basically I'd like to put the Castrol in the transfer in the next day or two even though the plan is Redline in the trans and there are leaky seals on this rig. Ok to do this?