Help identifying smell !!

[Sotovo]

Hello all,

I am in need of some help. I have a 1998 limited 4x4 with 170k miles on it. There's is a pretty weird smell that occurs when I put the pedal to the metal. When I fully floor the gas pedal, a weird smell of rubber burning/exhaust fumes(?) happens, or maybe a burning rubber... It comes through the A/C vents and if I have the windows down it's worse. But the vehicle drives great and is in great mechanical condition.

Took it in for an oil change today and the toyota specialist said it's not an exhaust leak for sure because he checked.

But I don't know. This is my first toyota and I'm unsure of what it could be. I haven't driven much after the oil change so maybe it's gone now, but I'm not sure what it could possibly be. But it only occurs when I really open the throttle and really redline her. Which I dont do often, but just sometimes for the heck of it. haha...any help is appreciated.

 

[02SE]

Well,, if a Toyota Specialist had the 4Runner in front of him, and couldn't determine the source of the smell, how are a bunch of people on the Internet going to be able to identify it?

I'd take it to another, more competent specialist, and get another opinion.

 

[Kanger328]

I have a similar issue. I smell slight exhaust fumes at idle, but at WOT the smell is much worse. I believe I also smell what you refer to as the "burning rubber" smell...not really burning rubber, but burning something. I passed this off as just a reality of driving an older vehicle. You have a '98 model, so it's roughly 16 yrs old (mine is older). I'm assuming the fuel isn't burning as cleanly as it did when new. The fumes can escape through many different places and it's probably just seepage through one of those places.

I say this because I recently noticed the smell got REALLY bad. I discovered I had a crack in my exhaust just before the cat. Got it welded up and the smell improved significantly, but still there. So my conclusion, some sort of fume leak. If you want to try and fix it, check the entire exhaust system for leaks from headers to cat to muffler. Do a tune up (if not done already), change O2 sensors, etc. My $0.02.

 

[98OzarksRunner]

Might be the cat. I had a 95 that had a bad smell and when the cat finally went bad (guts fell apart) and I put a new one on it, the smell was gone. It smelled like the exhaust of an old dump truck or something, and most of the time I didn't notice it, except when passing or something like that (WOT).

 

[mxer]

Well,, if a Toyota Specialist had the 4Runner in front of him, and couldn't determine the source of the smell, how are a bunch of people on the Internet going to be able to identify it?

I'd take it to another, more competent specialist, and get another opinion.

Maybe out of the thousands of members someone else has experience this same problem and knows how to fix it?

 

[viceversa]

I just picked up my first 4runner and also experience this but I'm fairly sure its one of the belts. From my brief inspection under the hood, it seems the alternator belt is too loose. Might be slipping a bit at WOT and burning some rubber off the belt.

TLDR: check your belts.

 

[donkeyhoatie]

I just picked up my first 4runner and also experience this but I'm fairly sure its one of the belts. From my brief inspection under the hood, it seems the alternator belt is too loose. Might be slipping a bit at WOT and burning some rubber off the belt.

TLDR: check your belts.

I had a similar issue with a Nissan Altima recently. Horrible burnt rubber smell. I thought it was the belt slipping, but it turned out the alternator pulley and the alternator themselves were both bad. Replaced it and the issue was resolved.

 

[ki1022]

is your valve cover leaking? Probably oil dripping on to the exhaust and burning off. Hold the throttle at high RPMs and watch around the valve cover gasket with a flashlight for drips. It's a pretty common problem on 3rd gen 4runners.

 

[cfranck1]

Do you have the rear window (rear hatch) down while driving it? It will come into the cabin when acceleration from all the turbulent air behind the vehicle.

If so close the rear window and try your shot gun starts and see if the smell goes away?

 

[02SE]

Maybe out of the thousands of members someone else has experience this same problem and knows how to fix it?

Maybe you can smell his 4Runner through your monitor, but I can't. It could be any number of things.

Without smelling what he is smelling, and inspecting the vehicle, it's impossible to say what the issue is.

 

[viceversa]

Maybe you can smell his 4Runner through your monitor, but I can't. It could be any number of things.

Without smelling what he is smelling, and inspecting the vehicle, it's impossible to say what the issue is.

you need to install the e-sniff browser plugin bro!

Seems like OP is at a loss for what to check. Providing some key areas to check can do no harm here.

 

[Run 4 Fun]

Maybe you can smell his 4Runner through your monitor, but I can't. It could be any number of things.

Without smelling what he is smelling, and inspecting the vehicle, it's impossible to say what the issue is.

What's the point of these forums right? People should just stop posting any questions where there is sound, smell, or feel involved cause we can't physically be there to inspect...

Just pulling your chain! That's what this whole forums is about, helping others out when they're stumped. Things to check because someone else might have experienced is pretty vital in some cases. Like the old saying, the only stupid question is the one not asked.

 

[02SE]

Seems like OP is at a loss for what to check. Providing some key areas to check can do no harm here.

Alright, he said he smelled burning rubber. My advice would be to look for anything made of rubber, which is burning.

Seriously, there are so many possibilities that it would be a disservice to him to try and list them all.

I used to diagnose noises, smells, vibrations, etc. on consumer cars, for a living.

I tend to be a little blunt and to the point: His best bet is to have someone that's qualified, take a look at it in person.

 

[Sotovo]

Well,, if a Toyota Specialist had the 4Runner in front of him, and couldn't determine the source of the smell, how are a bunch of people on the Internet going to be able to identify it?

I'd take it to another, more competent specialist, and get another opinion.

He didn't actually drive and try to diagnose it, he just checked for exhaust leaks while changing the oil. He is a very competent specialist, been doing Yota's since 73!

 

[Sotovo]

I have a similar issue. I smell slight exhaust fumes at idle, but at WOT the smell is much worse. I believe I also smell what you refer to as the "burning rubber" smell...not really burning rubber, but burning something. I passed this off as just a reality of driving an older vehicle. You have a '98 model, so it's roughly 16 yrs old (mine is older). I'm assuming the fuel isn't burning as cleanly as it did when new. The fumes can escape through many different places and it's probably just seepage through one of those places.

I say this because I recently noticed the smell got REALLY bad. I discovered I had a crack in my exhaust just before the cat. Got it welded up and the smell improved significantly, but still there. So my conclusion, some sort of fume leak. If you want to try and fix it, check the entire exhaust system for leaks from headers to cat to muffler. Do a tune up (if not done already), change O2 sensors, etc. My $0.02.

That's great advice! I do intend on replacing 02 sensors, and some other PM as the weeks progress. Thanks so much.

 

[Sotovo]

Might be the cat. I had a 95 that had a bad smell and when the cat finally went bad (guts fell apart) and I put a new one on it, the smell was gone. It smelled like the exhaust of an old dump truck or something, and most of the time I didn't notice it, except when passing or something like that (WOT).

I just really can't pin point what it smells like most lol... It's either exhaust or burnt rubber. Sometimes it smells like more than one than the other, and sometimes it's a mix. It looks like Im going to need to just replace things until I find the problem. Which I'd like to do anyhow. New stuff, less issues. Thanks for the info!

 

[A.Wilson013]

He didn't actually drive and try to diagnose it, he just checked for exhaust leaks while changing the oil. He is a very competent specialist, been doing Yota's since 73!

He should drive and diagnose it. :cheers:

I could be wrong, but I imagine the only things that get hot enough to burn/melt rubber would be exhaust components...? I'd start at the block and follow it back to see if anything is touching the exhaust system.

If nothing is touching, I'd then drink a finger (or two) of my favorite scotch and start touching stuff in the engine bay with my fingers until something hurt. Then I'd look for rubber stuff touching that thing that burnt me.

If all of that failed I'd stop driving it, let it sit in my garage for a few months, forget about, then maybe, someday, call a mechanic and schedule a diagnosis appointment.

 

[Sotovo]

Maybe out of the thousands of members someone else has experience this same problem and knows how to fix it?

Haha God forbid I see if anyone else maybe had the same issue??

 

[Sotovo]

I just picked up my first 4runner and also experience this but I'm fairly sure its one of the belts. From my brief inspection under the hood, it seems the alternator belt is too loose. Might be slipping a bit at WOT and burning some rubber off the belt.

TLDR: check your belts.

Wow good to know! I will definitely do that. That is what my thought is as well. There's got to be some sort of friction happening. Thanks for sharing!

 

[Run 4 Fun]

If nothing is touching, I'd then drink a finger (or two) of my favorite scotch and start touching stuff in the engine bay with my fingers until something hurt. Then I'd look for rubber stuff touching that thing that burnt me.

If all of that failed I'd stop driving it, let it sit in my garage for a few months, forget about, then maybe, someday, call a mechanic and schedule a diagnosis appointment.

Lol!