I have a '91 4Runner, 22RE, 5 speed manual, 108K miles. Just bought it from the original owner around a month ago. I get this hot smell, sort of a burnt electronic smell almost, when driving under load. Most of the time it only happens driving offroad going uphill but I am seeming to notice it every so often onroad going up longer hills as well. This thread from '02 describes my issue really well but there is no resolution, https://www.yotatech.com/forums/show...ight=hot+smell.

When I smell it the coolant temp is good, the oil level is good, I have pulled the dipstick & oil fill cap and smelled the oil and it does not appear to be coming from there. Initially I thought it was the clutch but it doesn't smell like clutch. Also there is no clutch slippage whatsoever & I took it to a transmission guy who sat in the rig and felt the clutch engagement and thought it was completely normal.

Everything else on the rig is great. It runs & drives excellent. I'm concerned though that I'm doing some sort of damage just continuing to drive it. Any ideas on the source of the smell? Any thoughts on how to diagnose it?

Thanks in advance,
-Roger

 

i'm not sure i can really offer any solution, but i smell the same kinda thing from my '95 auto 4runner whenever the engine has to strain going uphill or gassing it offroad. i used to worry about it, but its been like that for so long and there seems to be nothing thats being damaged. i think its just the smell of the engine as it gets hot (still at a perfectly safe temp.) i've tried lots of times to find the source of the smell and cannot pinpoint it to anything particular. i've smelled the same kinda thing in my bro's grand cherokee the few times he has to really gun it and drop it into third to get up a hill, so i don't think its anything to worry too much about, IMO. hope that helps put your mind at ease a little.

 

I think the overwhelming majority of 3.slows have this odor. My 91 had the same as well. But I would describe it as old, cheese-laiden, burning foot. It was only when I stepped on it. I blame it on the cat converter, but who knows.

 

Is the exhaust system or any parts of it new? That is often the source of a burning odor until the protective coating burns off. Can you rule out that it's NOT coming from under the hood? That in itself would relieve me a lot if I were you.

 

I'm almost certain there are no new exhaust components as the previous owner had all receipts & documentation on the truck and there is nothing in this area. The hot smell seems to be coming generally from the transmission area. You don't really smell it at the front of the truck, you pick up the smell standing by the side just behind the front wheel. And, this may be my imagination I don't know, it seems more prevalent on the passenger side.

Part of me thinks I'll just live with it and part of me thinks I should get to the bottom of it. I sure wish I knew what it was.

 

If it smells similar to a clutch burning smell. Check your brakes and make sure they are not dragging. Hot brakes smell like a burning clutch, and you an smell it at low speeds as there is less air flow to carry it away.

 

This had occurred to me as worthwhile to check. It doesn't smell like brakes or clutch but I'm willing to check most anything I can. If for no reason than to rule things in or out. What would be the proper way to check if my brakes are dragging?

 

Is it possible that you are smelling the rust film or may the better way to say is the road grime flim that builds up on the down pipe. It is noted in the other post that it could just be the smell of the metal parts getting hot or being hot, and burning off all of the stuff that has coated the system......I do not think that you have any thing major to woory about here....If you drive to those temps often then the smell does decrease.......

 

my 98 runner limited does this. it has done it from the day that i owned it, two years ago. it didnt change after i lifted my truck this spring. The only thing that changed is that how often it does this now. Everytime i try to go up a hill on the highway and it downshifts, i get the smell and it happens quite often. I was and still am a little nervous about it, but i just try to keep it under 3 grand on the tach. the smell doesn't change at all and hasn't in the two years i've had it.

 

My runner has the smell also,especialy when I drive with back window open so I think it must be coming from exhaust. Don't worry

 

Well man, I feel left out...maybe its because I've always had an air freshener in the car but I've never had the privilege of smelling this "hot smell." Sounds like its a normal thing to not worry about, as long as no temp lights are popping up on the dash and everything is running alright then you should be good.

You could try a tranny cooler and see if that helps, if not, well its still a good mod!

Good luck and don't sweat it,

Fink

 

yep i have this smell as well....its eaither something the exhaust or in the tranny because it happens to me when climbing hills at higher RPMs in 2nd or 3rd gear.

the same thing happens in my dads triumph

nobody knows what this is?

i was thinking maybe its the tranny?

 

I've got the same smell. I really noticed it after a fuel injector servicing. It's been like that now for a while. I've stopped worrying about it because I can't figure out what it is. Actually, I'm just lazy...

 

Same smell with mine too, freaked me out at first but now I try not to worry about it. Like payyourtoll, I blame it on the cat converter.

 

Same here. I've had that burning smell since I got my rig in January 2005. I don't know what it is and now I just live with it.

Troy

 

I first thought it was the old mud on my cat that was just frying an leting off a bad smell, almost like firework smoke mixed w/...well, u know. Anyway, everything in my car is filled and good. I just ignore it now.
-mike

 

I will tell you what it is. It is both the o2 sensor and the smell of an overheated cat converter. TRUST ME

 

I replaced both my Cats on my '00 T4R last year and I've still had this smell. Every 3rd gen that I personally know of has this smell when climbing hills, must be the 02 sensors then, I'll have to check those.