Burning smell

[Jaketino]

So I have been smelling something hot for quite awhile now but it has finally gotten to me and I wanna try to fix it. It occurs when I am either accelerating quickly (getting on to the freeway) or coasting down the freeway (right after I let off the gas). The only way I smell it is with the rear window down slightly and the front windows cracked which makes me believe it's something below the vehicle like the diffs or something. I'll check the diff fluid tomorrow to make sure that's fine. Any other ideas?

 

[D Farms]

I think it might be the exhaust being sucked into the truck a little bit, or if there is any tar or grime on the exhaust it could just be getting hot then and getting sucked into the truck. btw also happens too me.

 

[JRZEE2000TR4LTD]

Get underneath. Look for leaks. What ever it is has to be getting on something hot. (exhaust or manifolds) Could be a number of different things. The usual suspects are leaking valve cover gaskets. Check all your fluid levels. Look for wetness and follow it forward. ie if your transfer case is wet don't assume that's leaking as it could be something forward from it and just getting blown back while driving. Just like when some think their rack and pinion is leaking when really it's the valve cover gaskets dripping down unto them. When you smell it pull over when it's safe and try to find the culprit. I doubt it's a gas leak, that's a pretty distinctive smell.

 

[traffic61]

I have noticed on occasion, that I get a whiff of what I assume to be my slowly failing catalytic converter. It is usually after pulling off the highway with the rear window down.

Hope yours is nothing major.

 

[BlackCat914]

same here. There's nothing to worry about, it's normal.

 

[So Many Roads]

exhaust + carbon monoxide. your brain cells will thank you for closing the rear window.

 

[Jaketino]

exhaust + carbon monoxide. your brain cells will thank you for closing the rear window.

But that rear window is one of the reasons I love my 4runner!
It is just the back window though. I've tried combinations of the other ones and smell nothing. I'll be climbing under there soon to check for leaks and burnt material though. I'm just worried that it's the diff for some reason. Don't want to hurt that locker!

 

[slomatt]

Have you recently greased your u-joints? if they are over filled they can fling grease on the exhaust which results in a burning smell.

- Matt

 

[98OzarksRunner]

I have noticed on occasion, that I get a whiff of what I assume to be my slowly failing catalytic converter. It is usually after pulling off the highway with the rear window down.

Hope yours is nothing major.

Exactly. I had the same thing on my 95 (2nd gen). It smelled like something burning, and sometimes like a dump truck. When the guts of the cat finally broke loose and started rattling around (it went from smelling like a dump truck to sounding like one), I put a new cat on it and the smell went away completely. Sounds like you'll be buying a cat one of these days.